Sustainable Vegetable Growing Demo

I certainly had no expectations for this session . Billed as a Vegetable Growing Demo we gathered at 7pm last evening. Initially the turnout was barely adequate, but after 15 minutes we had a respectable number, perhaps 18 folk. The session started oddly. Helena asked us to uncross our legs, close our eyes and listen to the birds. I mused on whether we would be asked next to all hold hands and sing Kumbaya! But that was an unworthy thought, because Helena then ran a 90 minute session that was a tour de force on sustainable growing.  

We did introductions and gave Helena a sense of our knowledge and skill levels. From that she deduced our needs; high priorities articulated were management of diseases and pests, sustainable methods and productivity. As a professional market gardener supplying local markets and restaurant trade her immediate responses showed she knew her business, but critically important to her was the sustainability of practices.  

The demo moved into high gear as Helena demonstrated some key guidance:

  1. Community working. Central objective of the evening was to create a first stage community project bed. The idea is to plant heirloom or heritage seed based plants and let them run fully cycle to seed, that then provides an initial stock of saved seeds for sustainable growing for potentially the entire community in their own plots. Some of us already practice seed saving, but mostly in an ad hoc manner. Helena showed and urged us to focus on developing seeds that we demonstrate for ourselves that grow well in our specific environment.
  2. Inter planting. Companion planting if you like, but not as you know it!. The idea is to establish guilds that complement, not just in demand for nutrients and soil type, but also deters weeds and pests. Example: Alliums, carrots and salads, plus pest deterrent flowers such as nasturtiums. A further aspect of inter-planting is to cover all the ground with green manure, to prevent weed growth or comfrey leaves to provide slow release of nutrients. Helena will provide detailed notes on practical guilds and all the aspects of the demonstrated practices.
  3. Multi-purpose feed and feeding. Many of us make Comfrey tea, often adding nettles for raised nitrogen and perhaps egg shells for balance. Helena uses an array of herbs in the tea also to provide targeted pest and disease prevention in addition to nutrients. Again Helena will be sending recipes and suggested timing of use.  
  4. Communal resources. Taking the ideas of feed to the next stage, Helena recommends we establish communal resources for source plants (herbs, comfrey, nettles etc) and stocks of various types of feed. The amount of space for this wouldn’t be huge.

Helena talked as she planted, setting up pea supports in the process. We all then got involved in planting and the bed was full in jig time.

The process is continuing with one demonstration a month through August. Utterly brilliant exercise in teaching and demonstrating a viable approach to sustainable growing. In the process Helena covered pretty much all the questions that were raised at the start of the session and many more. A really professional grower practicing what she teaches, as well as a hugely inspirational teacher!

Blarney Castle Gardens

Over the past couple of years Marie and I have been lucky enough to live just a few Kms from Blarney Castle and its gardens. While Blarney Castle must be one of Ireland’s most well known and most visited tourist attractions, the surrounding gardens themselves must also count as a national treasure. During lockdown it has been an amazing facility to walk around the gardens and trails, and with or without lockdown we typically walk there at least twice a week, sometimes more. On our visits we have often chatted to the gardeners who do such an amazing job across a wide range of formal and informal gardens, as well as the more remote areas through the woods and beside the lake and rivers. In this way we learnt about the volunteer gardeners who provide support to the professional gardeners that develop and maintain this huge gardening effort.
So this week I felt very privileged to join one of the two groups of volunteer gardeners and help in the overall effort, and to become part of this great gardening effort.
My first session was in the huge walled garden pruning apple trees. The orchard comprises a huge variety of species, about half are well established, the other half relatively newly planted.
We focused on the established trees. Our lead gardener talked us through the pruning task:
The core advice went something like this:
First for each tree remember “the three Ds”. Look for and deal with Dead, Damaged or Diseased wood. Second consider the shape of the tree – whether its pyramidal or chalice like and ensure any pruning supports the development of that shape. Third make minimum necessary cuts. This was particularly interesting. These trees have been regularly pruned and the shape is mostly pretty good. But making minimum necessary cuts to maintain the shape, ensure growth lets light to all parts of the tree, keeping branches from growing into each other.
Third, in trimming growth, don’t cut fruit buds unless really necessary and leave three leaf buds in place.
The point about minimum necessary cutting is reinforced with the idea that while pruning in February is recommended. Pruning throughout the year has advantages – you can see what new growth needs attention and encourage and or discourage growth where it’s needed. So revisiting the pruning task in April/May is useful.
I asked about feeding; the expert guidance is not a lot of feeding is necessary. Certainly not every year. But removing grass and weeds around the trees and mulching every year is important.
With this guidance I found that most of my time was spent studying each tree, and making careful decisions before each pruning cut. And where I wasn’t sure, particularly in the case of diseased or damaged wood, I asked for expert guidance.
I’m definitely no expert, but I did feel I now have a rationale for each tree and each cut. Which is very different to how I have pruned in the past which has been guided more by tree shape and less by branch by branch decision making.

Autumn 2020 – Session 5 (14/12/2020)

Diseases are microbial; Pests anything bigger!

Diseases: three main pathogenic microbes: virus, bacterial, fungal

Fungal diseases spread through the air; 1 cell organism

Most vegetable diseases are caused by fungi. They damage plants by killing cells and/or causing plant stress. Sources of fungal infections are infected seed, soil, crop debris, nearby crops and weeds. Fungi are spread by wind and water splash, and through the movement of contaminated soil, animals, workers, machinery, tools, seedlings and other plant material. They enter plants through natural openings such as stomata and through wounds caused by pruning, harvesting, hail, insects, other diseases, and mechanical damage.

Black spot – Fungal leaf spot attacks lettuce and can also occur on brassicas and other vegetables including such as cabbage, cauliflower, Chinese cabbage, broccoli, Brussels sprouts, kohlrabi, kale, turnip and rutabaga.

Damping offDamping off is a disease of seedlings caused by several different fungi and fungus-like organisms. This disease causes emerging seedlings to collapse, often submerged in a mass of white fungal growth. It is particularly a problem when sowing seed indoors or under glass.

Black Leg Potato blackleg is caused by the bacteria Erwinia carotovora subspecies atroseptica. Bacteria remain dormant in seed potatoes and become active when conditions are right, making it both unpredictable and brutal. Like with cole crop blackleg, there are no sprays or chemicals that can stop this blackleg, only cultural controls will destroy the disease. Blackleg symptoms in potatoes typically involve very inky black lesions that form on infected stems and tubers. Leaves above these spots will yellow and tend to roll upwards. If the weather is very wet, affected potatoes may be slimy; in dry weather, infected tissue may simply shrivel and die.

Cole crop (brassicas) blackleg appears first on young plants as small brown lesions that expand into circular areas with gray centers covered in black dots. As these areas grow, young plants may die quickly. Older plants can sometimes tolerate a low-level infection, causing lesions with reddish margins. If these spots appear low on stems though, the plants can be girdled and will die. Roots can also become infected, causing wilt symptoms including yellow leaves that don’t fall off the plant.

Grey MouldGrey mould, caused by the fungus Botrytis cinerea, is a very common disease, causing a soft decay of plant tissues accompanied by a growth of fuzzy grey-brown mould. It affects many plants, especially those grown under glass where conditions are humid. It is also a common disease of soft fruit, such as gooseberries, strawberries and grapes. Also onions just before harvesting.

Mildew(Powdery) mildew grows as a white powdery coating over the surfaces of leaves. Pea, bean, okra, cucumber, squash, muskmelon, and pumpkin are common host plants. Leaves around the base of the plant are first affected. This fungal disease is favored by warm weather and can be destructive in dry as well as hot seasons.

  • Mildews
    • End of life cycle
    • Plant is weak
    • Especially peas and beans
    • Wet summer

All the fungal diseases are accelerated by weather conditions

[Signs and symptoms of plant disease: Is it fungal, viral or bacterial?]

Irish climate inherently conducive to fungal diseases; relatively little that can be done once a plant is diseased. So preventative measures are essential:

Start by planting healthy stock. … check seed descriptions for “mildew resistant”

Choose planting sites based on plant needs. …  maintain plant distance

Remove affected material immediately

Avoid overhead watering. …

Water early in the day. …

Don’t crowd plants. …

Don’t work a wet garden. …

Ensure good airflow, keep tunnel doors open

Control Weeds

But in the end there’s little that can be done (in an organic situation).

Potato Blight is prevented by bluestone  (copper sulphate) solution. Seals leaves to prevent spores attaching to the plant.

Tomato blight –  . .

Strictly blight spraying is not allowed by the International Organic System. But each country has its own overlays and it is accepted in Ireland. However, we know fluids travel up AND down the plant stems. So, we must ask whether we are happy with copper sulphate in our potatoes?


Organic Trust

Organic Standards

(and find they are not clear or helpful?) ☹

Also can try Horsetail Tea

Horsetail is a beautiful, highly invasive and incredibly resilient plant; a great survivor. With roots growing 10 feet and more into the earth and a history of survival stretching back over millions of years to the time of the dinosaurs, it is extremely difficult to erradicate so I never have living plants in my own garden and dispose of any roots with caution.

Horsetail is a powerful plant, rich in minerals, alkaloids and silica, used in some biodynamic preparations as well as extensively in herbal remedies. A natural fungicide, horsetail ‘tea’ is used to treat fungal problems including powdery mildew and black spot and makes a magnesium rich spray which can be applied directly to plants and as a soil feed. The spray helps to prevent damping off, rust, treats mildew on roses, make a root dip,is used to treat peach tree leaf curl and is an effective, purifying cleaner for greenhouses and cold frames.

Weed Control Actions

  • Square foot gardening
  • Dense planting
  • Mulching
  • Stale seed bed
  • Flame thrower!!
  • Allow 1 or 2 seed growths and then sow out
  • Boiling water (kills weeds)
  • Vinegar

Pests: A pest is any animal or plant harmful to humans or human concerns. The term is particularly used for creatures that damage crops, livestock, and forestry.

General strategies:

  1. Plant out more than is needed
  2. Plant sacrificial crop
  3. Plant perimeter crop to deter (e.g radishes)
    Companion Planting: Effects of Radishes on Squash Bugs
  4. Plant spicy leaves on perimeter
  5. Biological control (see Bacillus thuringiensis below)
  6. Parasitic wasps
    BBC report on Parasitoid wasps
    I note from FHF site that Borage is recommended as favourite plant for beneficials (spiders, damsel bugs, ground beetles, parasitoid wasps)
  7. Ecosystem problem? Move entire site for a few years! (drastic? Actually not necessarily if plots available!)

Pest Specifics

Slugs, snails, (no natural predators except thushes, geese, ducks). Remove, mulch, find in March). Good garden hygiene removes hiding places, use gravel paths, ensure nowhere overgrown. Use Neudorff organic slug pellets also stocked by Griffins, Dripsea

Note slugs eat toxic foliage (e.f rhubarb leaves) , and are themselves toxic

101 ways to kill a slug

Caterpillars, cabbage white month mid summer. Consider biological control – bocillis thurengiensis . . .

Bacillus thuringiensis (Bt) is a natural occurring, soil-borne bacteria that has been used since the 1950s for natural insect control. It consists of a spore, which gives it persistence, and a protein crystal within the spore, which is toxic.

for control of larvae of wax moths and other moth species, larvae of mosquitoes, black flies, and other flies, many types of caterpillars, larvae of elm leaf beetle, larvae of elm leaf beetle

BUT . . . Not cheap see Fruithill farm below . . .

Alternatively consider Bionet netting, bit cheaper!!

Greenfly, blackfly, wooly aphids, aphids (love greenhouses, wet and warm conditions, really vicious little teeth, attract or buy ladybirds), they feed in clusters, usually on the undersides of leaves near the point where the leaf attaches to the stem, or on tender young shoots and buds. As they feed, they secrete a sticky fluid called honeydew. When enough aphids are feeding on the tree, this honeydew will begin dripping from the leaves. Solution – encourage ladybirds with wide variety of flowers.

Try Limnanthes douglasii (poached egg plants) around your raspberries and soft fruits: they will attract bees and so improve pollination and fruit production while also encouraging hoverflies which will feed on aphids.

Also consider natural insecticide spray, (deadly) nightshade leaves crushed with garlic, washing up liquid and cold water. (actually garlic alone works also IME)

NOTE: Blarney Castle Gardens has a Poisonous Plant Garden

Blarney Castle’s Poison Gardens are located behind the castle battlements. Though at a glance they may seem like any other botanical garden, warning signs with skull and crossbones and cages carefully constructed to contain the deadliest of the plants reveal this is no ordinary garden. . . Wolfsbane, Mandrake, Hellebore, Hemlock, Nightshade, and Ricinus communis, which produces castor oil and the lethal poison ricin.

white fly, root flies (carrot and cabbage),

cabbage fly – use collars around the plants

wire worms – trap with sacrificial potato plants

flea beetles, small bugs, tiny beetles attach to young brassicas/rocket and spicy leaves. Whole plant is riddled with holes!

also use nematodes – not cheap!!  . ..  small, usually microscopic, unsegmented roundworms with a narrow cylindrical body. They are not a pest and occur naturally in the soil. Buy from Fruithill farm

ants (find eggs at end of summer, white pearls – expose to birds),  . . .

Pigeons – love brassicas

Coypu (in River Lee?)

NZ Flatworm – attack and eat earthworms. Kill on sight!!


Plants manufacture their own food under the influence of sunlight. It happens in the leaves of plants and is distributed to the rest of the plant via the stems.  Note the stems separate transport (similar to the human arteries and veins) to facilitate transmission of water and oxygen (simplistically) up to the leaf structure and sugars down to the roots. When a plant is damaged the plant can be helped by cutting away damaged leaves and stems.

Carbon + Water = Sugars + Oxygen

CO + H2O = C12H22O11  + O

(note the chemical or molecular formula for sucrose is C12H22O11, which means each molecule of sugar contains 12 carbon atoms, 22 hydrogen atoms and 11 oxygen atoms.)

Credits: Many thanks to our tutor this term –
Selvi Lyilikci and the Cork Education Training Board (CETB)

Autumn 2020 – Session 4 (7/12/2020)

Solanaceae (Nightshades) and Composting Workshop

Continuing last week’s session . . .

Solanaceae or Nightshades

. . . are Potatoes and Tomatoes, (plus for completeness eggplant, bell and chili peppers). The Nightshade varieties are all hungry and need a lot of organic matter. They don’t like poor soil. Guideline: One Wheelbarrow load of compost per sq yard! Just to put that into context, that’s THREE barrow loads for an FRC raised bed!


Three main habits: Bush, Intermediate (Upright) and Tumbler.

Main issue with Tomatoes is getting them to ripen.

Keep foliage to minimum is really important. Cut side shoots off from day 1. Keep bottom of stem clear with lots of light.

Train into one main leader.

Sow Jan/Feb indoors. Plant out when strong. Feed once per week with comfrey or other liquid feed.

Pests and Diseases: Like potatoes, can be susceptible to blight. Little that can be done. Make sure the soil is not reused. We’ll talk about aphids next week.


Checkout the RTE programme – currently on the Player

1st Early – March – St Patrick’s Day planting should be regarded as a guide to be adjusted depending on the weather

2nd Early – April

Main Crop – June

Plant deep;

Plant as Deep as Possible

In figure above: LH planted too shallow. RH planted deep or (dotted line) earthed up. Note the potato is a strong plant and in good soil should produce 12 potatoes per plant.

Another way to earth up is to plant in an old tyre and then add second tyre as the plant grows.

Fresh manure will burn (scab).

Potatoes originate from South America; grown at altitude in the Andes blight wasn’t a problem because of the dry conditions. In Ireland’s damp climate blight is inevitable. Note no seed potatoes are grown in Ireland. All done in Scotland (presumably at altitude!!) Answer to blight is a) rotate crops. b) use blight resistant varieties (Sapo Miro or Bionica). or c) plant earlies and get them out of the ground by July when humid conditions occur. “IRISH GROWERS REALLY NEED TO CHANGE VARIETIES”. Checkout Fruithill Farm for lots of guidance and ideas for varieties.

Answer to wire worms – clean out soil a) with a sacrificial crop or b) picking out by hand! I recall Margaret Griffin recommended covering the ground with black matting before planting. Wireworms will come up to the surface for the warmth and after just 24 hours can be picked off. (I haven’t tried this myself, but it sounds like sense).

Beetroot: Always 2 or 3 plants in each seed.

Moderate feeders.

Composting Workshop

Brown – Carbon

  • Fall leaves
  • Pine needles
  • Twigs, chipped tree branches/bark
  • Straw or hay
  • Sawdust
  • Corn stalks
  • Paper (newspaper, writing/printing paper, paper plates and napkins, coffee filters)
  • Dryer lint
  • Cotton fabric
  • Corrugated cardboard (without any waxy/slick paper coatings

Green – Nitrogen

  • Grass clippings
  • Coffee grounds/tea bags
  • Vegetable and fruit scraps
  • Trimmings from perennial and annual plants
  • Annual weeds that haven’t set seed
  • Eggshells
  • Animal manures (cow, horse, sheep, chicken, rabbit, etc. No dog or cat manure.)
  • Seaweed

Use chicken wire to keep out the rats

Use newspaper in same quantity as vegetable scraps

Working too slowly – add C

Too acidic – add lime

Always add N activators – Fresh manure, Chicken pellets, Seaweed or seaweed pellets

Which Items Are “Greens” and Which Are “Browns”?

Next week: Pests and diseases. Last session before Christmas . . Bring mulled wine and mince pies.

Autumn 2020 – Session 3 (30/11/2020)

Families and Rotation


Savoy cabbage, spring cabbage, red cabbage(slugs less keen on), Kale (high return)*- curly, (black) Tuscany, red (Russian),(easiest to grow)Brussel Sprouts, Cauliflower, Calabrese (broccoli), Chinese greens, Pacchoi, rocket, Radish, turnips, swede, sprouting broccoli*,

All brassicas are hungry and need a lot of N and rich soil, rotted horse manure. Also extra feed (tea) during the growing cycle, Kale not so much.

*Continuous cropping

General note: When a plant is stressed (too hot, too cold, insufficient water, disturbed, attacked by pests or animals etc) it goes into flower. Essentially a response to protect itself by triggering the next stage in its growth cycle. No point in cutting the flower off.

General note: Most vegetable flowers are edible. Go very well in stir fries.

IDEA! Worried aboutseeds?Easy Germination test – sprinkle a few seeds on moist kitches paper and leave.

General discussion re planting: In general higher success (in Irish climate) with potting seeds rather than sowing seeds straight into the soil. Two stage potting, small then larger; plant out when the plant is sturdy enough to withstand pests etc. 2 months maximum (lack of nutrients in potting compost, plant on or out)

If a green leaf turns purple, it is stressed, Not enough space or nutrient.

Biggest issue with brassicas is pests, cabbage white (July/August) and aphids.

Use bio net (small mesh), or biological control Biological Control and Natural Enemies of Invertebrates  and or grow flowers that attract lady birds, or “buy” ladybirds!  

Bio controls can be parasitic wasp (eats aphids) or organic biological caterpillar. (NTS More research needed here . . . . )


Onions (white, red), leeks, garlic, scallions, chives (perennial herb), shallots,

Mostly easy to grow. Perhaps except red onions that will go into seed very easily.

Sets should be good and big, Can produce sets yourself, but need to start January.

Cropping onions – wait for foliage to tuen brown, then bend the stem to close the bulb over. Leave on soil to dry. Hang when dry not before.

Alliums don’t need rich soil, but will be improved by feeding.  


Peas (garden, mange tout, sugar snaps), beans (runner, french (climbing or bush), broad (rich source of protein),

Don’t pull legumes plants, cut the stem at ground level. Leave the roots to rot in the soil and leave all the N in the ground.  

Solanaceae  or nightshades, are a South American family of flowering plants that ranges from annual and perennial herbs to vines, lianas, epiphytes, shrubs, and trees, and includes a number of agricultural crops, medicinal plants, spices, weeds, and ornamentals.

Deadly nightshade (toxic foliage also used as pesticide), potato family, peppers, aubergines, tomatoes, chillies,

Apiaceae or Umbelliferae is a family of mostly aromatic flowering plants named after the type genus Apium and commonly known as the celery, carrot or parsley family, or simply as umbellifers.

Carrots, herbs, parsley, parsnips, coriander, lovage (perennial herb) celeriac

The Chenopodiaceae family includes plants without petals that often grow in soil rich in salts or nitrates. Spinach (not resilient), beetroot, Swiss chard (or rainbow), beets.

Circubits, squash cucumber, melons, pumpkins, courgettes (Zucchini) colorful, come in all shapes and sizes, and are easy to grow.

Aster or Asteraceae Asteraceae, also called Compositae, the aster, daisy, or composite family of the flowering-plant order Asterales. With more than 1,620 genera and 23,600 species of herbs, shrubs, and trees distributed throughout the world, Asteraceae is one of the largest plant families. Artichokes, lettuces etc

Quick Notes Rotation etc

Don’t grow in same place year on year. Legumes don’t need rich soil, they create their own N

Next Week: Compost Making workshop   (Bring Kitchen scraps, Chicken Pellets, Leaves, etc)

Final Week:  Pests and diseases

Credits: Many thanks to our tutor this term – Selvi Lyilikci and the Cork Education Training Board (ETB)

Autumn 2020 – Session 2 (23/11)

Nutrients and Minerals

Seaweed is the best all round fertiliser. Contains all nutrients and minerals. Use natural seaweed or purchase granules as a top dressing.

Nitrogen (N) is important in early growth and is used a lot in vegetable production to speed up growth to happen in the short growing season (particularly in Ireland).

Yellowing leaves often indicate a magnesium deficiency. Can use Epsom salts as a top dressing.

Phosphorous (P) for roots – e.g parsnips, turnips, beetroot

Potassium (K) for fruit and flower – e.g  squash, courgettes, peppers

Carrots “hate” N. The tap root goes deep to find food, so if they get nutrient from the topsoil they will spread or splay. Carrots do best in sandy, fine soil which is almost depleted of nutrients.

Cabbages, potatoes need lots of N. Chicken pellets is a good strong source.

Bird manure tea.

Animal manures are all strong in N. Note the smaller the animal the stronger the manure. E.g guinea pigs, rabbits, chickens, worm casts all make very strong manure.

Note do not use fresh. Must be decomposed or well-rotted. Also add to compost heap or bin as an activator. Chicken pellets same.

[Exception to the (smaller the better) rule?]  Horse manure is even stronger in N. Be careful very “hot” manure will burn roots. Needs 3 – 6 months to decompose. If you leave manures eventually they will decompose into soil then into slurry (watch for pollutant in water courses).

The heat in a compost heap or bin is caused by bacterial decomposition. You can even heat soil or water from this heat source.

Soil can be covered with variety of materials. Wool, foliage, mushroom compost, old carpet, old compost (contents of last year’s pots).

Other Organic Fertilisers

Plants: Comfrey, green manures (clover, mustard etc), Use comfrey or nettles as compost accelerators, or anything rich in N, such as chicken pellets.

Seaweed can be used as a top mulch. Cover to accelerate breakdown.

Wormeries: acquire starter kit with series of bins. Most nutritious compost. Great way to manage kitchen waste. Checkout “wiggly worms Donegal”.

Consider separating tea-based feeds for nettles, comfrey and seaweed.

Note bulky fertilisers are the base. Foundation for the year’s growth and structure for the soil. Liquid feeds are additives applied when needed, or as a medicine.

Credits: Many thanks to our tutor this term – Selvi Lyilikci and the Cork Education Training Board (ETB)

Autumn 2020 – Session 1 (16/11)

Very often we describe Organic growing in negative terms – “. . . we don’t use . . .herbicides, (weedkillers), or pesticides (oil based synthetic chemicals)”. But we are all aware that commercial horticulture is based on mass usage of these products. Ireland is a laggard in Europe. Consider Austria they are 40% organic. Checkout Teagasc to get an idea of how important organics is. Latest figures from DAFM show that there are 62 organic dairy operators with an average herd size of 79 cows (2019). That makes organic dairy farms 0.3% of the market. Organic horticulture is a niche industry as explained in the Teagasc fact sheet.

Up until 100 years ago organic horticulture practices were the de facto standard. But since then we have steered away from natural practices. So what are the principles of Organic Growing?

Organic growing is about paying great attention to the soil. Biodiversity boosts ecosystem productivity where each species, no matter how small, all have an important role to play. For example, a larger number of plant species means a greater variety of crops. Greater species diversity ensures natural sustainability for all life forms. Diversity of life in the soil leads to greater resilience to pests and diseases. The living soil comprises macro organisms (worms, millepedes, insects, bugs etc) and micro-organisms (virus, fungi, bacteria, nematodes etc)

Ecosystems contribute their greatest ecological value when they are in their most natural state. We can encourage natural ecosystems to adapt to local circumstances (climate, topography), and use local varieties that thrive in the natural state. These concepts are the opposite of “monoculture” – the de facto commercial growing approach.

Side note: In Ireland “we” struggle to produce good potato crops because we persist in growing varieties (such as British Queens, Golden Wonder, Kerrs Pinks etc) that are not inherently blight resistant.

Rotation has been practiced for thousands of years (certainly from Roman times). Moving crop families (Brassicas, Alliums, Solanums, Legumes etc ) each year prevents development of pests and diseases and reduces risk of specific nutrient depletion.

Living Soil:

Soils have different make up, acidic/alkalinity, structure, and different macro and micro-organisms even within a plot.

The skeleton of soil is made up of the “particles”. Big, small and tiny. All evolved from weathered rock over millions of years. Basic structure is Gravel, Sand and Silt (sediment). Soil types vary by region; often on basic rock types such as limestone, most have mixture of soil particle types.

Particle structure is key – bigger particles allow more air and more drainage. Example Berlin is 100% sand – no water retention. Also very poor levels of nutrients as they are washed away. All soils can be characterised by level of “soil water” the permanent level of hydration.

Clay has high levels of soil water and is fertile and rich in nutrients; however hard to work and often water logged and cold. A healthy mix is a sandy loam; aim for 50:50. Note silt is usually a minor ingredient.

Key to soil improvement is organic matter. Decaying matter, bulky, leaves, grass clippings, seaweed (particularly seaweed), horse manure. 5% of topsoil should be organic matter. Bulky matter adds structure and nutrients. Reduces soil compaction. Encourages worms and other macro and micro organisms. Worms eat organic matter and create worm casts – full of nutrients. As per diagram above soil fertility is achieved by managing all these elements which are all interconnected.

In general aim for soil that is light brown with dark brown parts, some clay. Should be able to make a “sausage”.

Best fertiliser is seaweed – contains everything for plant growth. Iron, trace minerals etc. Add bulky stuff – keeps soil bacteria active in breaking down. Also consider seaweed granules/powder. Use liquid feed only to boost development. Facilitate nutrient cycle with moisture, dark, little disturbance that changes Nitrogen into nitrates (soluble in water) that can be taken up by plant roots.

Finally manage acid/alkalinity – aim for 6.9 which is neutral, optimum for most plant groups. The alkalinity (pH) of highly acidic soils can be raised by incorporating limestone or seaweed into the soil.

Next session: Organic fertilisers and crop groups.

Credits: Many thanks to our tutor this term – Selvi Lyilikci and the Cork Education Training Board (ETB)

Notes from Horticulture Class 6 – Saving Seeds

Heirloom. Varieties grown in certain regions, that have stayed the same for generations. People swap and share seeds and the variety becomes indigenous, specific to a region because they perform well in specific climate or soil conditions.

Good example is Daniel O’Rourke Pea.  Perfect round and delicious green peas in a pod! Daniel O’Rourke Pea is considered an Irish heirloom from the 1800s by Irish Seed Savers Association. They found this long lost variety preserved since 1921 at the Vavilov Institute for Plant Industry in Russia, and brought it back into cultivation and circulation in Ireland. It was named after a winning British thoroughbred racehorse, perhaps because it was known as the earliest pea cultivar at the time. The horse was named after a character in an Irish folktale who was carried to the moon by an eagle. Some report that this is the same pea as horticulturalist, breeder, and seedsman John Sangster’s “Sangster’s No. 1 Pea”, a very popular variety in the mid- and late-1800s on both sides of the Atlantic. It is used as a fresh shelling pea, and also as a dry pea for soups. Thanks to Irish Seed Savers for this seed, and to artist Christine Mackey for her research on this pea’s history.

Back in history, most seeds were local to communities. Of course as society evolved, railways and transport allowed people to move around, seed varieties became commercial products and more widely used.  

Most Heirloom seeds are Open Pollinated. “Open pollinated” generally refers to seeds that will “breed true”. When the plants of an open-pollinated variety self-pollinate, or are pollinated by another representative of the same variety, the resulting seeds will produce plants roughly identical to their parents. (Wikipedia)

So the genetics of Heirloom seeds are quite stable. For example, the Daniel O’Rourke pea has been tested from one generation to the next over many years and shows no change.

It should be said that change can and will occur in Heirloom seeds – as Open Pollinated seeds have the ability to adapt their genetic structure to changing climate conditions. This change will happen over multiple years, responding to changes such as average temperatures, rainfall etc.

Example of Open Pollinated seeds:

MUSSELBURGH LEEK. The Musselburgh leek was originally imported from France and first cultivated in the town of Musselburgh in Scotland. This area of Scotland is not renowned for its mild weather and this variety of leek is perfectly suited to the very cold winters in this area. The same inherent genetic structure (ignoring changes in response to climatic conditions) will have existed for over 100 years.  

Open Pollinated seeds are available from niche suppliers who offer varieties that are not usually found in the mass market retail trade. Examples:

Brown Envelope Seeds (West Cork)

Real Seeds (Wales)

W. Robinson & Sons  (Seeds and Plants)  See Heritage Pages

Irish Seed Savers Association (Clare)

Hybrid F1

The mass market seeds most commonly found in retail and online stores are Hybrid F1.  These seeds are generally combinations of two different species of plant which are crossed to produce an offspring that delivers specific characteristics such as higher yield, sweeter, uniform shape or taste, ease of processing, size, uniformity of ripening/harvesting. These characteristics are often targeted at commercial growers who want to optimize harvesting costs and shape to meet retailers’ quality (sic) requirements. These of course are frequently in direct conflict with the objectives of small growers who look for staggered ripening and harvesting.  

Crossing two genetically different plants produces a hybrid seed. This can happen naturally, and includes hybrids between species (for example, peppermint is a sterile F1 hybrid of watermint and spearmint). In agronomy, the term “F1 hybrid” is usually reserved for agricultural cultivars derived from two parent cultivars. These F1 hybrids are usually created by means of controlled pollination, sometimes by hand-pollination. For annual plants such as tomato and maize, F1 hybrids must be produced each season. (Wikipedia)

In summary, Hybrid F1 is essentially a form of genetic modification. And it is very difficult to retrieve a heirloom variety once it is lost along with the skills. If you save Hybrid F1 seeds you will not get the same results in the second year. It is likely the crop will be lower in quantity and or quality.

Evidently we have lost 80% of the Heirloom varieties over the past 50 years. It’s also important to note that the major seed producers are huge corporations, often bringing seeds to market under numerous well-known brand names such as Suttons, Unwins etc. Clearly we have become very dependent upon just a very few large corporations which concentrates skills and knowledge in relatively few heads that you might consider represents a risk to our ability to feed ourselves.  

In contrast, saving our own seeds allows us to have control and independence over our entire growing process.

Saving Seeds

Annuals (peas, beans, tomatoes, sweet pea etc) can be saved in one life cycle (6 – 8 months).  These seeds are genetically stable and produce the same results year after year. Annual seeds will last literally thousands of years. (E.g perfectly usable seeds were found in the pyramids of Giza!)

Tomatoes very easy to save – take a jam jar, some water, squeeze the tomato and it will release its seeds. Cap and shake the jam jar, leave for 3 – 5 says. The acid in the tomato breaks down the gelatine around the seed and allows the seed to separate. Leave for further 3 days. Pour into sieve, wash and allow to dry. Then pick off seeds into a brown envelope.

When saving seeds, select plants to save from that are healthy, ripe, vigorous. Have no disease, pest damage.

Biennials – Onions, brassicas etc

After harvesting onions – store best examples. Not from bolting plants. Plant out in spring next year and allow to go through to flower.  Collect seeds.

Same for carrots, parsnips, beetroot. Note carrots will grow in 2nd year to huge size (6’ x 4’)

Harvest seeds when the plant is fully ripe and when dry so seeds have little moisture. Cut flowers and leave lying in a tunnel to dry. The objective is to achieve a balance between losing moisture and yet not fully drying out. Store in brown envelopes or glass jars. Brown envelopes are best.

The seed is still a living part of the plant. But the moisture content has dropped so low that growth has almost stopped. Need to keep cool and dry, but not too dry.

There are differing requirements for specific seeds, see sample references below.

University of Minnesota Saving Seeds

Gardening Knowhow – Storing Seeds

RHS Seed: collecting and storing

US Dept. of Agriculture

United Nations Seets Toolkit

Johnny’s Selected Seeds – Storage Guide


Question: Tomato ripening but browning. Why?

Answer: Probably giving it too much water. Remember tomatoes come from Mexico, and they don’t have a lot of water. Water 1litre every 3 days is sufficient.

Notes from Horticulture Class 5 – In the Weeds

Actually “weeds are not all bad”. After preparing the soil it doesn’t do any harm to leave young, small weeds such as redshank, chickweed etc to grow, and it facilitates retention of moisture. Additionally young weeds don’t harbour pests and or diseases until they are around 6 – 8 weeks old. Many annual weeds are also edible – e.g chickweed, lambs quarter, red shank (well IMHO that’s debateable), dandelion and nettles. The latter two of course very difficult to eradicate if left too long.

Weeds are also full of nutrients and will enrich the soil if left to decompose on the ground or provide good base for fertiliser. Ideally weeding is done on a wet day – hand weeding carefully pulling weeds including the roots. Need to be removed, otherwise if left on the soil damp they will survive to grow another day.

Similarly don’t create a heap of weeds for the same reason – some will survive. Better to remove and use to make a liquid feed or put in the compost bin as all nutrients are useful. Otherwise you are probably just putting your own fertiliser back into the bin!

On dry days a short hoe is recommended. Never hand weed where a hoe can reach. Recommend an oscillating hoe – with a swivel head and double, D shaped blade that cuts on both forward and backward movements. Best time on a dry day is mid-afternoon, when the air rises with the heat from the sun (well this is Ireland) and creates breeze that dries the roots. These roots can be left in situ and act as an excellent mulch.

Question: What is the nutrient mix of types of weed?

All plants contain the same nutrients. Just some break down faster and easier than others. In general leafy plants will have more N than P and K. In their early stages of growth they will all have a mix of all macro and micro nutrients. Weeds also contain water and Carbon. Nettles have more N. Note here the Latin name for nettles is Urtica dioica – from which we might assume Uric acid is derived which is high in N. Hence the “stinging” nettles.

In contrast Comfrey is high in P and K. The Comfrey roots are deep (question to self, are nettle roots shallow, yes of course!) and therefore take nutrients from deep down in the soil. Dock would have the same nutrients as Comfrey, BUT the reason we like the latter is it’s leaves are far easier to dissolve in water.  The leaves would also be generally high in chlorophyll. The N high stems tend to be structural and cellulose – higher in carbon; and less easy to break down. (I did interject here, that I do use the stems of Comfrey in the tea bin, primarily because the extended immersion in water greatly softens the stems and acts as a precursor stage for composting.

Lot of discussion about how to know what nutrient proportions the tea will have. Danger of “overloading” which will produce undernourished plants, sickly discoloured leaves and plants that we more susceptible to pest attacks. Overloading may also lead to lush growth – plants that are not strengthened in proportion to their size, and which do not mature properly. In onions, bulbs may be large and full of sap. Carrots may fang (excess N).

Rule of thumb (for tea making ) is 10:1 won’t go wrong.

In general don’t over feed plants. It’s easier to pinpoint under nourishment than over nourishment.

When planting in the Spring it’s a good idea to break the surface of the soil to allow weeds to germinate – using up the weed seeds all at once. Allow the weeds to get to about 1” or so and then just before sowing, remove weeds. Call this a “stale weed seed bed”. (I like that).

Alternatively kill off weeds mechanically with hoe (as discussed) or blow-torch!!! Using a small torch (roofers) is a good way to kill weeds. Further it sterilises the soil. And evidently organic growers are moving into burning, particularly because it doesn’t disturb the soil, and therefore allow weed seeds to surface. (No dig method). Now it might also kill/damage good bacteria, and the jury’s out on what is the best approach. Called “flaming”. (Nothing to do with over enthusiastic social media activity).

 Other ways of killing weeds involving some form of mulching:

  • covering with clear polythene after weeds germinate  – heat of the sun kills and sterilises. Use tunnel cover polythene. Make up wooden frames the size of beds and cover. Try the Co-op for polythene.
  • “weedblock” membranes.
  • also cardboard works well for larger plants such as brassicas. Might need to install a watering system – e.g weepy pipes or (better) holey bottles as small reservoirs.
  • leaf mould (high in N)
  • checkout geeup (composted horse manure very good for mulching). Locally made in Blarney.

The advantage of mulching is that it retains moisture – whereas if you just strip weeds the soil dries. Use mulch particularly for shrubs (fruit?) and permanent crops.

Speaking of mulching . . . Consider a separate compost bin for leaves. Keeping separate is probably best in order to keep brown and green matter in proportion. Leaves are quite sterile and v dry and break down better if kept separately. (Living green leaves are considered “green materials”, whereas the dead, dry leaves that fall from the trees in autumn are seen as “brown materials”. Autumn leaves are a great source of carbon and contain a surprising amount of nutrients that can be returned to the soil through compost.)

Discussed several options for weed block – mypex, non biodegradeable covering material. Woven weed block. Non woven – oil based doesn’t fray. Sheeps wool – quite thick, light and degrades slowly over 2 seasons. Also can use hemp/cotton fibres, woven better than sheeps wool – they tend to be denser and don’t allow light through. However this can be expensive  (like €3 / sq m). Double the cost of weedblock.

Re non biodegradeable blocks, we need to consider the “end of life” cost. In general we need to be investing a little more upfront in order to avoid end of life costs (not just our landfilling charges but the cost to the environment in the long term). Biodegradeable is clearly the way to go.

For all these materials checkout the garden shop.

. . . or fruithill farm. (West Cork based organic pioneers).

Finally a good layer of seaweed. The trick with seaweed is to keep it moist. Mix with normal peat moss helps to retain moisture. And apart from the peat moss, it’s free if you go and collect it!

Next week: Harvesting seeds and everything about seeds!!

Notes from Horticulture Class 4 – Planting and Companion Planting

The Three Sisters Companion Planting Pattern

Planting generalities

Planting is a succession of activities requiring decisions on timing and quantity. At the heart of this is timing.

Think about plants in two sets – tender and hardy.

Hardy plants can be planted before the last frosts in spring (mid May) and will include brassicas, potatoes etc. While frost will burn potato leaves they will not be badly damaged.

Tender plants should only be planted out from June onwards. Planting out from seed not advised until there is no risk of frost, irrespective of seed type. Soil temperature should be at least 10 and if possible 12 degrees. Generally mid to end May.

Root crops are generally sown direct into the ground in tunnels or with some protection. Some varieties can be outside but most will be inside in mid May.

Plant seeds outside end May and into June. There’s always temptation to plant too early. But time is better spent tidying or preparing the ground. Plantings of  carrots, parsnips and turnips in early June will always catch up with earlier sowings.

Tender plants such as pumpkins or squash should be planted in tunnels and planted out 2 – 3 weeks later. If plantings are too early they may “sulk”. Not showing any growth. Recommend delay sowing seeds so that planting out happens in June.   

Provide heat in cool weather by using cloches – e.g use 10 – 20L water bottles, with bottom cut off for single plants. Or storage boxes.

Alliums (onions, shallots, etc) bulbs are fully hardy – can be planted into the ground in autumn when < 10 degrees, or in spring when soil is a cool 6 degrees. But note, onions grown from seed need minimum 12 degrees.

Corn on the Cob

Need good flowers – Male and female. Male flowers are at the top of the plant. Female flowers midway down the plant where the cobs will form. Pollen falls from the Male to the Female. Like any flowering plant corn need P and K. Not so much N.  Use comfrey tea plus seaweed. Or use a general tomato feed.

Companion Planting

Companion planting has been practised for thousands of years – longer than today’s commercial “mono planting” practised by commercial growers. Mono planting evolved at the same time as mechanisation in the 1700’s – enabling large plantations of single crop. Prior to that companion planting was the de facto approach.

Where mixed crops are growing together every plant needs light, shelter and nutrients. Low growing crops with bigger crops with higher leaves, e.g corn and squash, will need to be spaced out to allow the squash to grow on the ground and suppress weeds. In this pattern add sunflowers and runner beans, where the runners use the corn for support. Four different plants in one plot. Beans, corn and squash are referred to as the “three sisters”. Native Americans used that system for generations.

The growing pattern is also nutrient symbiotic. The Beans are N fixers producing N that the corn consumes. Squash consumes P and K. None of the three plant types use an excess of nutrients to the detriment of the others.

Into this pattern you can add Nasturtiums. These attract bees that help pollinate the squash and corn. In this pattern corn spacing will be 24” rather than the mono crop spacing of 16”. Generally it is advised to grow as big as corn crop as possible – to ensure pollination happens and also to provide natural shelter. A minimum size corn crop would ideally be 5m x 1m. (full typical raised bed). This would be 24 corn plants.   In practice smaller crops are of course feasible but hand pollination might be necessary (shake the plants or use an old paint brush).

Similar CP pattern might be:

  • Carrots and Onions,
  • General root crops such as beets, carrots, onions.

Carrots, onions and Leeks. Where carrots are deep rooted, onions are shallow rooted and leeks happily grow with the others.  Also can add beet all spaced appropriately. Further benefit is the smell of leeks deter carrot fly.

Just need to remember the rules of CP – ensuring adequate space, light, nutrients for all of the component plants.

Note squash would not work as the leaves are too big and block out the sunlight.

Further thoughts on CP

Companions can

  1. repel insects and pests
  2. attract beneficial insects.


Marigolds under tomatoes – smell of marigolds masks smell of tomatoes and deters white fly.

Garlic and carrots – deters carrot fly

Nasturtiums around apple trees – deters woolly aphids, attracts bees

After 3 years Nasturtiums kill off all woolly aphids.

Deter slugs with:

  • marjoram
  • herb Robert (make extract and spray)
  • ginger (make extract)
  • Horse chestnuts (collected prior year, crush and sprinkle around beds)
    note quite potent
  • Cyclamen – liquidize or chop finely and sprinkle

Attract pests – with sacrificial crop

  • Protect Hostas from slugs – plant sacrificial lettuce nearby
  • Protect potatoes from wire worms – plant Cara variety potatoes (remember you can spread wireworms on your tools) 

What should not be planted together?

  • Carrots and beans (compete for light)-
  • Beans and peas  (compete for light?)
Create your website with
Get started