National Vegetable Society Questiontime Evening - The Answers!

NVS GQT

Sweet potatoes need a long growing season, grow them under polythene, RHS trials. Go for the variety Beauregard. Grow on before planting out as they are frost tender.
Parsnips – sow on kitchen roll and cover with cling film. Carrots are best modular sown, opt for a carrot free resistant variety such as Flyaway and Resistafly. Carrot flies fly low, no higher than 2ft (60cm) nesh is required, but planting alliums close by will help too!
Dobies and Suttons offer a leaf beet, perpetual spinach, the secret is to grow the crop quickly, efficiently and with plenty of moisture available to them.
Leek moth (RHS)

Leek moth is mainly a problem in southern England but it is spreading north. The caterpillars feed within the foliage and stems or bulbs of leeks, onions and related vegetables.

What is leek moth? The adult leek moth is an inconspicuous very small (5-6mm) brown moth. Its larvae (caterpillars) feed on leeks and similar crops.

Symptoms Damage from leek moth caterpillars appears as;

White patches developing on the foliage where the caterpillars have eaten the internal tissues
Tunnels in the stems of leeks and bulbs of onions, shallots and garlic
Affected plants often develop secondary rots and young leek plants may be killed

Note that these plants are also attacked in a similar manner by larvae of a fly, known as the allium leaf miner;

Leek moth caterpillars are creamy-white with brown heads and small legs
Larvae of the leaf-mining fly are white, headless maggots with no legs

Non-chemical control The female moths can be prevented from laying eggs by covering susceptible plants with horticultural fleece, or an insect-proof mesh such as Ultra-Fine Enviromesh. Look for the white, net-like silk cocoons on the foliage and squash them.

Chemical control None of the pesticides available to amateur gardeners for use on leeks and onions is likely to give effective control.

Biology Leek moth has two generations during the summer with larvae damaging the plants;

From the first generation in May-June
And the second generation in August-October
The second generation is the more numerous and damaging

Initially the caterpillars mine the foliage but the older larvae bore into the stems and bulbs.

When fully fed, the caterpillars are 11 mm long. They come out of the plant and pupate within net-like silk cocoons that are spun on the foliage.

Adult moths emerge in autumn and overwinter in sheltered places.

Quick facts

Common name Leek moth
Latin name Acrolepiopsis assectella
Plants affected Leek, onion, shallot, garlic
Main symptoms White patches on leaves, with young plants rotting and dying. Small caterpillars may be seen in the plant tissues
Caused by Caterpillars of a small moth
Timing April-October

Allium leaf miner The allium leaf miner was first detected in Britain in 2002, since when it has spread in the Midlands and has also been found in Surrey. The larvae bore into the stems and bulbs of leeks, onions, chives and garlic with devastating consequences. Affected plants often develop secondary infections and rot.

What is allium leaf miner? Allium leaf miner is a pest of many common crops: leeks, onion, chives, shallot and garlic. The initial damage is done by the maggots, but secondary fungal and bacterial infections often cause the most noticeable rotting.

Symptoms The first sign of an attack from allium leaf miner is the presence of the adult fly:

The greyish brown flies are 3mm long
Before laying eggs, the female flies feed by making punctures in the leaves and sucking up the exuding sap
This causes distinctive lines of white dots on the foliage

Next seen is damage from the maggots:

The larvae are white, headless maggots without legs
These make tunnels in the stems and bulbs of their host plants
Note: Similar damage is caused by caterpillars of the leek moth but that pest has creamy white larvae with brown heads and small legs

But perhaps the most obvious signs of a problem appear when rotting sets in:

Plants affected by both allium leaf miner and leek moth tend to rot due to secondary infections from fungi and bacteria that develop in the damaged tissues
On closer inspection, cylindrical brown pupae may also be found embedded in the stems and bulbs

Non-chemical control

Plants can be protected by covering them with horticultural fleece, or an insect-proof mesh such as Ultra-Fine Enviromesh, at times when the adult flies are active and laying eggs (March to April and October to November). Crop rotation must be used, as adult flies might emerge from pupae underneath the fleece covering if susceptible plants are grown in the same piece of ground in successive years.

Chemical control None of the pesticides currently available to amateur gardeners for use on leeks and onions is likely to give good control of allium leaf miner.

Biology Allium leaf miner has two generations a year:

First generation female flies lay eggs on the stems or base of leaves during March to April
The second generation repeats the process in October to November

The maggots bore into the stems or bulbs of their host plants and, after a couple of weeks, are fully fed and ready to turn into brown pupae. Pupation takes place mainly within the stems and bulbs during summer and winter but some pupae may end up in the soil, especially where plants have rotted off.

Make all AGM veg NVS veg – makes sense, does it?

1. It’s good to know where your vegetables have come from. When you start growing your vegetables organically you will know they are free of pesticides and that they are fresh and have not taken weeks or months to be flown to a supermarket. Organic Vegetables taste better and are more healthy. You can even pick and eat vegetables in the garden, as there will be no chemical residues to wash off.
2. Be safe in the knowledge that your garden is environmentally and animal friendly with no toxic chemicals. If you have pets or children around at least you’ll have piece of mind that they will not be picking up slug pellets (even the so called organic ones) which are toxic to cats, dogs and hedgehogs. Hedgehogs need to be welcomed into your garden as they are very good slug and snail eaters. There are more organic solutions to control slugs and snails here.
3. Make or Buy your own Compost Bin to make your own soil improver Making your own compost not only recycles your vegetable peelings, grass cuttings, newspapers and old plant material but it also puts lots of nutrients and organic matter back into your vegetable plot or garden. This will continually improve the soil your vegetables or plants are growing in and make your vegetables grow bigger and better. Please see my Guide to Building Your Own Compost Bin.
4. Use Organic Fertilizers to improve your soil whilst your compost is being made. If you are only just starting your compost bin and still need to improve your soil, there are organic fertilizers on the market which are animal, plant or mineral based. For all round nutrient based fertilizers use pelleted chicken manure or seaweed. As with all fertilizers its best to wear gloves whilst applying it. Other organic fertilizers include: Bonemeal which helps root growth, Dolomitic Limestone is used to raise the soil PH. Potash contains potassium and helps with deficiencies, Seaweed Meal helps with the humus build up within the soil. Fertilizers are best applied at least 2 weeks before sowing.
5. Learn about beneficial insects and wildlife so they can be the pest control in your garden Lets be honest slugs and snails are the annoyance of anyone’s garden or vegetable plot but a few simple solutions could help to eradicate some or all of them. Hedgehogs love slugs and snails and so do frogs and birds. If you welcome wildlife into your garden by providing them with a home, shelter and food, they can do the pest control for you. Ladybirds and lacewings should also be encouraged if your garden has aphid or green/black fly problems.
6. Use organic seed whenever possible Try to choose varieties which are recommended for great taste or are resistant to disease. There is a large range of organic seeds in the Organic Garden Catalogue.
7. Be Water Wise in the garden Try to only water the vegetable plot when rain is not forecasted or buy a water butt or tank and harvest water from a down pipe on the house, shed or garage guttering. Rainwater is good for vegetables as it makes them put on a spurt of growth so by recycling rainwater in the garden, you are not only saving money but giving your vegetables the boost they need to keep growing.
8. Reduce weeds by planting thickly and mulching. Weedkillers contain toxic chemicals which can get into the soil and water courses so to prevent using them in the garden try planting flowers or vegetables close together wherever possible. Weeds need soil, space, water and sunlight to get growing so take away the sunlight by mulching with grass cuttings, wet newspaper or compost or covering the area over to prevent them from growing.
9. Use Eco friendly wood and natural preservatives. FSC (Forestry Stewardship Council) wood comes from sustainable sources and is therefore eco-friendly. Check for the FSC logo on compost bins or garden furntiture before you buy. Treat wood with a non toxic wood preservative like Procol Fencote from the Organic Gardening Catalogue or source a natural oil or resin paint.
10. Try Crop Rotation and Green Manure in your vegetable garden. If you are not growing your vegetables in plots of types, it may be worth considering for example Brassicas (cabbage, kale, broccoli), Roots (carrots, spring onions, parsnips, beetroot), Beans and Peas and Onions. Potatoes are a good crop to plant on soil that needs to be broken up for planting in the future. Rotating your vegetable crops each year helps improve disease resistance and it reconditions the soil. If you have a bare patch in your vegetable plot try growing a green manure to fertilise your soil and stop weeds growing.

Sweet corn needs a long growing season, and warmth and lots of it. So opt for a early maturing variety such as Swift (F1) Good performance in cold soils and keeps reasonably compact.
Squashes need warmth and generally we tend to sow them too early (so don’t sow before April). Sow the seeds on their edge, to help the radical of the root.
Apart from variety I suspect the below average temperatures have compounded the problem. Try Lady Di (10-12in beans, stringless) and the newish variety Moonlight (a runner/French cross), famed for its tasty beans, its good set in cold weather and reliability.
This is a hot topic at the moment – issues with Westland Compost, The Sun and Peter Seabrook. Best Before Date is something I think should also be addressed
Salad crops, pumpkins and squashes, tomatoes.
Grow blight resistant varieties and make this a community drive on plots and simply preventatively spray. Blight Alert via e-mail.www.blightwatch.co.uk

Parsnip canker: This orange, brown or purple-coloured rot usually starts at the top of the root. It is mostly caused by drought, over-rich soil or damage to the crown.
Remedy: Sow resistant cultivars such as ‘Avonresister’ and ‘Archer’, improve drainage and avoid damaging the roots. Avoid sowing seeds too early in the year. Protect from carrot fly.
Carrot fly: Larvae of this fly tunnel roots so affected areas have to be discarded and it also allows easier infection by parsnip canker.
Remedy: Grow roots under insect-proof mesh.

Material which cannot be composted - diseased plants, meat and fish, dairy, cooked food, coal ash, cat and dog litter, disposable nappies and perennial weeds eg bindweed. Tree leaves need to be composted separately, except ash which should be burned.

15.

Think dry and cool no matter where you store seed. Humidity and warmth shorten a seed’s shelf life.

Keep seed packets in plastic food storage bags, plastic film canisters, Mason jars with tight-fitting lids, or glass canisters with gasketed lids.

The refrigerator is generally the best place to store seeds. Avoid the freezer however.

To keep seeds dry, wrap 2 heaping tablespoons of powdered milk in 4 layers of facial tissue, then put the milk packet inside the storage container with the seed packets. Or add a packet of silica gel. Replace every 6 months

Store each year’s seeds together and date them. Because most seeds last about 3 years, you’ll know at a glance which container of seeds might be past its prime when planting season comes.

When you’re ready to plant, remove seed containers from the refrigerator and keep them closed until the seeds warm to room temperature. Otherwise, moisture in the air will condense on the seeds, causing them to clump together.

Even if you’re organized, methodical, and careful about storing seeds, accept the fact that some seeds just won’t germinate the following year. Home gardeners will find that stored sweet corn and parsnip seeds, in particular, have low germination rates, and other seeds will only remain viable for a year or two.

News story in Amateur Gardening magazine... Specialist nurseries say a ban on peat could put them out of business – and wreck efforts to conserve plants that are now extinct in their natural habitats.

The UK government wants to ban peat use by amateur gardeners by 2020 and halt its use at nurseries by 2030.

However, other EU countries do not intend to phase out peat. And Dutch peat firms are reported to be gearing up to flood the UK market with imported plants, if UK nurseries shut up shop.

“Some of the plants we exhibit are now extinct in the wild, but we need peat to grow them,” said Matthew Soper, of Hampshire Carnivorous Plants in Southampton.

“If a peat ban comes in we’ll have to stop. I don’t know what we’re going to do. I’ve heard people say there’s no place for peat but that’s a load of rubbish.

“Of course, peat shouldn’t be used as a soil improver, but certain species need it.

“We have trialled the alternatives but had disappointing results – they just don’t work. English growers will be put at a disadvantage to the Dutch,” Matthew warned.

Dave Parkinson, co-owner of east Yorkshire-based disa orchid specialist Dave Parkinson Plants, agreed.

“We have two choices: peat or sphagnum moss,” Dave said.

“If we had to use sphagnum moss, our 40-50,000 plants would need re-potting once or twice a year, as the moss starts to break down.

“I just wouldn’t do it. We’d shut. If we lose peat, I’m finished. We’ve looked at alternatives for 20 years and there’s nothing in the same league as peat.”

Dave said that disa orchids grown in peat alternatives “stop growing and die” and claimed that compost containing recycled green waste is too high in nutrients.

“It kills them [disa orchids] within a week,” he said.

Dave, who uses 60 per cent coarse grade peat in his compost mix, summed up: “It’s ridiculous. There’s got to be a place for peat for plants that need it. I stopped hybridizing two years ago.

“I don’t see the point if I can’t get the stuff to grow them in.

“I used to do 100 crosses a year but now I can’t see any future.

“We are the only country in the world that’s talking about banning peat. All the rest are discussing extracting it from sustainable sources.”

17. Yes, coffee grounds will help deter slugs, however... Gardeners using coffee granules to deter slugs breaking EU law – RHS

Gardeners struggling to keep slugs at bay this summer by sprinkling coffee granules around the veg patch may be breaking EU laws, the Royal Horticultural Society has warned.

Caffeine in the coffee deters slugs and snails

One of the wettest summers ever has encouraged slugs and snails to attack cabbages and lettuce.

But organic gardeners trying to deter the pests without resorting to chemicals by using old coffee granules are in contravention of EU regulations and technically face heavy fines.

The RHS issued the warning in the Garden magazine after being flooded with inquiries.

It is well known that caffeine in the coffee deters slugs and snails and many coffee shops give away old granules to help out local gardeners. Tea leaves are also said to work as a deterrent.

But Dr Andrew Halstead, principal scientist for plant health at the RHS, explained that any “home-made” remedy that has not been approved by Brussels bureaucrats is against the law.

This is to stop people using dangerous mixtures on plants that may be eaten in future or spreading chemicals that may harm wider wildlife.

Dr Halstead told a Sunday newspaper it was easier for the EU to include chemicals that have been tested and approved as pesticides on a list, and impose a blanket ban on everything else, rather than produce a longer list of ingredients that are potentially dangerous.

"All chemicals being used to control or deter animals are classed as pesticides in the UK and EU, and must be registered and approved for this purpose by our own government and the EU. Legislation requires potential pesticides to be extensively tested for effectiveness, environmental safety, operator safety and safety of breakdown products before they can be sold and used,” he said.

Dr Halstead warned that in theory gardeners could face heavy fines - although prosecution is unlikely.

“Anything that has not been through the system is illegal to use as a pesticide, however safe that chemical is perceived to be. Heavy fines can be imposed for breaches of the laws relating to pesticide use; however, the chances of being prosecuted for scattering coffee grounds in a garden are, I suspect, remote.”

However, gardeners can still use coffee granules as compost, Dr Halstead added.

"If you were to use coffee grounds around plants with the intention of providing some organic matter in the form of a mulch, rather than as a slug control/deterrent, then the regulations relating to pesticides would not apply. This may all sound rather daft, but the intention of the pesticides legislation is to prevent people from applying untested dangerous chemicals."

Gardeners also use beer traps and salt to kill slugs. Garlic steeped in water and smearing chillis paste on plants is also said to work. Vinegar or soap and water can be used to kill insects on plants. Nicotine insecticide, made by soaking cigarette butts in water, is used by some gardeners.

Anne Wareham, author of the Bad Tempered Gardener, said the EU law is “ridiculous”.

“You are probably not allowed to water your garden,” she said. “After all, H20 is a chemical.”

18. Medwyn’s tips on collars, pretty extensive... Collars

The two rows that I have of the cleaned up Welsh seedling from Ivor Mace are really looking powerful and are now on 37.5cm collars and will very soon be in need of 45cm collars and they are thicker than a broomstick handle. One word of caution, don't be in too much of a hurry to increase the collars on your leeks if they have not made the necessary growth to go with it. Ideally you want to increase the height of your collars in proportion with the girth of the leek rather than pulling them too fast when they are too thin and incapable of putting on any weight because at the same time they are trying to grow upwards.

The collaring material that I use is builders damp course, this is a very flexible tough black plastic material which you can easily cut to different sizes using a sharp knife and can be bought in a roll at any Builders Merchant and a roll should last you for years.The last collar for me this year will be 52cm which means that with the leek being planted deeper that usual I should be aiming for a length of approximately 60cm. The 30cm collars made from pipe lagging have also by now been removed so that from now on all I need to do is to keep a sharp eye out for pests and diseases.

19. No-dig gardening

No-dig gardening is a non-cultivation method used by some organic gardeners. The origins of no-dig gardening are unclear, and may be based on pre-industrial or nineteenth-century farming techniques.^[1] Two pioneers of the method in the twentieth century included F. C. King, Head Gardener at Levens Hall, South Westmorland, in the Lake District of England, who wrote the book "Is Digging Necessary?" in 1946 and a gardener from Middlecliffe in the UK, A. Guest, who in 1948 published the book "Gardening Without Digging". The work of these gardeners was supported by the Good Gardeners Association in the UK.^[2]Masanobu Fukuoka started his pioneering research work in this domain in 1938, and began publishing in the 1970s his Fukuokan philosophy of "Do Nothing Farming", which is now acknowledged by some as the tap root of the Permaculture movement.^[3] No-dig gardening was also promoted by Australian Esther Deans in the 1970s, and American gardener Ruth Stout advocated a "permanent" garden mulching technique in Gardening Without Work and no-dig methods in the 1950s and 1960s.^[4]

This technique recognizes that micro- and macro-biotic organisms constitute a "food web" community in the soil, necessary for the healthy cycling of nutrients and prevention of problematic organisms and diseases.^[5] The plants transfer a portion of the carbon energy they produce to the soil, and microbes that benefit from this energy in turn convert available organic substances in the soil to the mineral elements the plants need to thrive.^[6]

History

Historically the reasons for tilling the soil are to remove weeds, loosen and aerate the soil, and incorporate organic matter such as compost or manure into lower soil layers. In areas with thin soil and high erosion there is a strong case against digging, which argues that in the long term it can be detrimental to the food web in the fragile topsoil. While digging is an effective way of removing perennial weed roots, it also often causes seeds that can remain dormant for many decades to come to the surface and germinate. Digging can also damage soil structure, causing compaction, and unbalance symbiotic and mutualist interactions among soil life. Digging tends to displace nutrients, shifting surface organic material deeper, where there is less oxygen to support the decomposition to plant-available nutrients, which then need to be otherwise replenished. Digging is practiced traditionally in countries with old, deep, rich soils such as Western Europe, however traditionally there, this is followed by periodic resting of the soil, usually with an undisturbed cover crop.

Methods

No-dig methods allow nature to carry out cultivation operations. Organic matter such as well rotted manure, compost, leaf mold, spent mushroom compost, old straw, etc., is added directly to the soil surface as a mulch at least 5-15 centimeters (2–6 in) deep, which is then incorporated by the actions of worms, insects and microbes. Worms and other soil life also assist in building up the soil's structure, their tunnels providing aeration and drainage, and their excretions bind together soil crumbs. This natural biosphere maintains healthy conditions in the upper soil horizons where annual plant roots thrive. No-dig systems are said to be freer of pests and disease, possibly due to a more balanced soil population being allowed to build up in this undisturbed environment, and by encouraging the buildup of beneficial rather than harmful soil fungi. Moisture is also retained more efficiently under mulch than on the surface of bare earth, allowing slower percolation and less leaching of nutrients.^[7]

Another no-dig method is sheet mulching wherein a garden area is covered with wetted paper or cardboard, compost and topped off with landscape mulch.

A no-dig system is easier than digging.^[8] It is a long term process, and is reliant upon having plentiful organic matter to provide mulch material. It is also helpful to remove any perennial weed roots from the area beforehand, although their hold can be weakened by applying a light-excluding surface layer such as large sheets of cardboard or several thicknesses of spread out newspaper before adding the compost mulch. The newspaper or cardboard should be thoroughly wet as well. A popular book, Lasagna Gardening by Patricia Lanza (Rodale Press, Inc.) provides excellent instructions for the novice user.