However, with the basic pest control measures in place this damage can be kept to a minimum. Deciding the maximum damage that is acceptable depends on your own preferences but a threshold where intervention needs to take place should be decided before spraying becomes necessary. I never spray against pea moth Cydia nigricana, which means that I loose about a third of my pea crop. This is acceptable for me because I grow so many peas.
However, I used the copper based fungicide Bordeaux mixture on the potatoes this year to prevent blight damage because this devastates the crop. The trouble with spraying with this fungicide is that it will also kill the mycorrhizal fungi I added earlier in the year.
I do not tolerate any bindweed or mare's tail on the allotment and will dig down as far as I can to remove the rhizomes. They will regenerate but as weaker plants until they finally disappear completely. So sometimes the threshold is very low and sometimes much higher.
Planning for a rotation of crops so that nothing grows in the same position each year can prevent the buildup of soil based problems such as clubroot, Plasmodiophora brassicae and white rot, Scleterotinia cepivorum.
There is some suggestion that adding well rotted compost to the soil introduces microorganisms that compete with and reduce the virulence of diseases and pests in the soil. Adding organic matter to soil increases predators such as the soil centipede, Stigmatogaster subterranea.
Another suggested advantage of adding biochar to the topsoil; it has a large surface area and small pores which protect beneficial bacteria and fungi from larger predators.
|New allotment compost heap.|
Selecting cultivars that are resistant to diseases and pests, such as Clapton cauliflowers and Kestrel potatoes, is another way of avoiding the loss of crops this time of year. There is some suggestion that Great Bear F1 onions are resistant to white rot. I hope so.
Natural predators such as the slug nematode, Phasmarhabditis hermaphrodita, ladybirds, lacewings, ground beetles and hoverflies can be introduced or encouraged into the garden by creating habitat for them. Whether ladybird and lacewing boxes are of any use is debatable, however 10 cm hollow bamboo canes packed into a can do attract a wide variety of insects.
Barriers seem to be very effective in preventing damage to crops. I use blue water pipes as supports for scaffold netting. This netting has small holes which do not allow most pests to penetrate. I also use enviromesh, one inch and one centimetre mesh plastic netting, all of which are effective against pests.
A tidy garden is a good garden and leaves little habitat for pests like slugs and snails. I keep my allotment as free of weeds as time will allow. Hoeing regularly, even where there are no weed seedlings, prevents germinating weed seeds growing into seedlings. Developing a programme of weed control which includes hoeing the whole allotment once a week prevents a lot of problems.
There are no aphids on the beans at the moment but, when they are seen, I just take off the affected leaf or stem and put them on the compost heap. This seems to work effectively and prevents the aphids from spreading to the rest of the plants.
I have mulched the beans and covered the path with shredded woody organic matter. The mulch will help to keep the soil under the beans damp. Amazingly, I saw a honey bee collecting nectar from the bean flowers; something I have not seen for at least two years. I still had a good crop of beans showing that beans can be pollinated by a variety of insects but it is good to see honey bees again.
I haven't harvested any of the runner beans yet because I have been concentrating on picking the peas. There are quite a few small beans near the bottom of the plants.
The allotment on the right of the beans has been abandoned and the weeds are five feet tall, which could be a little disconcerting for the inexperienced gardener. However, I see this as my beetle bank where pest predators can reproduce and move into my allotment.
|Money Maker and Gardener's Delight|
They are being wound around the strings to support them. The strings have been buried under the plants when they were planted out and provide a stout support for them to climb up. The tomatoes are getting a regular watering of comfrey liquid and this seems to agree with them because they have lovely dark green foliage. It has been a good year for tomatoes.
|Victoria Plum Tree.|
I cannot rectify the leaning of any of the old fruit trees but I can open them up and allow light and air to reach the centre of the tree. As yet there is very little disease or pest damage, although I have taken off one new shoot on the plum which was covered in aphids. The small Opal plum had much more aphid damage because it had produced a lot of sappy wood. I reduced the aphid covered branches to about three or four outward facing buds giving it a much better wine glass shape.
I was a little disappointed with the potatoes this year. Usually the tops are enormous and very dark green. This year they seemed stunted and have been going yellow from the base. This is probably blight, however it is only a mild infection and the tops are still green.
I lifted a root and I was surprised to find some very good potatoes which I am endeavouring to devour this week. It does not matter how good the plants look, they must also produce a good crop. Big potato plants does not mean lots of potato tubers.
I think that I will keep an eye on them and possibly remove the helms next week to prevent blight from getting into the tubers.
I have been taking two foot paving slabs up to the allotment to make the foundations of the greenhouse and it has been very hot work. Not the kind of weather to be doing this kind of heavy work. Tomorrow there will be thunderstorms but I will endeavour to complete the foundations.