Catching up after cold winds, aphids and pest protection, seed quality and sowing now
Lack of rain and cold winds have put plants under stress, especially salads, spinach, chard, broad beans and peas; also warmth-loving plants such as climbing beans and cucurbits, which also have not liked the cold nights of early June. Don’t worry if your runner and French beans look pale because they need warmth to grow strongly with dark green leaves. Its not a question of soil nutrition, simply that these plants cannot access the nutrients they need when soil temperatures are lower than normal. The same applies to sweetcorn, courgettes and squash, outdoor tomatoes too, whereas peas and broad beans thrive in cooler conditions, and undercover the wind protection and abundance of sunshine has helped tomatoes to grow well.
On the other hand, my polytunnel basil was struggling until very recently, while in the greenhouse where nights are warmer, its healthy. Also I have watered the basil, and other undercover plants, more than usual because of the incredibly dry air pulling so much moisture from leaf and soil. Until June 12th, any light showers evaporated quickly in the wind.
Plant stress and aphids
The weather until June 12th has been unusual: relentless wind, less rain and our main pest (slugs) has been noticeably absent. Instead we have had the classic pest of a dry spring, aphids: on lettuce, broad beans and any plant under stress from dry conditions.
Aphids are most prevalent in spring as they breed faster than most other insects, so temporarily they threaten to take over, until their predators can increase in number. I find that their prevalence is temporary and soon, by the end of June, order is restored as ladybird larvae and other predators increase in number.
No dig with surface mulch helps this balance to be maintained because plants are less stressed than in unmulched, dug soils. Also you can reduce aphid numbers by watering, for example I have noticed a pleasing reduction in aphids on lettuce after increasing the amount of water, even drenching each plant briefly from the hose.
A final word on aphids is their annoying way of introducing virus diseases, as they suck on plant sap. The photos of parsley show a result of this and where you see deformed plants, usually with some aphids present, there is no remedy I know of except to pull them out (its ok to compost them) and replant. Examples are yellowing and dwarfing of carrot leaves, chard, lettuce and brassicas.
I have had some notable successes and failures with seeds from different sources. Best results are coming from biodynamic, https://www.bingenheimersaatgut.de/content/de/english-catalogue.html seeds from Germany. They are so good that I hope to help others in Britain to buy them without having issues of sending euros to pay for them.
An example is Bingenheimer dill which I sowed at the same time as some dill seeds from Mr Fothergills, in February in the greenhouse, then planted at the same time in late March. The Mr F. dill is now rising to flower, which is normal in June, but the Bingenheim dill is continuing in leaf. It was the same story for coriander, the Bingenheim cropped for an extra week, and their Lollo Rosso, Bianca and Bijella lettuce are giving great harvests.
Its approaching the time when a lot of second sowings can be made, and some have quite a brief window of opportunity, such as dwarf French beans now and carrots by early July, unless you are happy with an autumn harvest of small carrots. I sowed some between garlic but then sparrows have been taking dust baths there!
In the next fortnight I am sowing purple sprouting broccoli, beetroot, Florence fennel, frisee endive, Palla Rossa chicory and flat leaf parsley.
Meanwhile I have leek plants ready to go in after for example, early potatoes. Also plants of red cabbage, savoys, French beans and even Brussels which I have yet to plant, and need to! It has been difficult finding enough space because of the demand for my salad leaves, meaning the garden has around 900 lettuce plants growing at any one time, as well as plants for flavour such as sorrel and herbs, then the oriental leaves from August (no rush to sow them yet).
Pests to come
Oh joy. Be prepared with mesh covers, or fine netting, against butterflies and moths. I reckon to lay a mesh cover over all plantings of cabbage for autumn hearting, and leeks because the moth is prevalent hereabouts.
Whether you need to cover or not depends on which pests are bad in your area, for example you may not have leek moth and I hope not! Its larvae have been tunnelling in some of my garlic stems too.
Currently I have mesh over most carrots but in recent June’s the fly has been absent, sometimes one is lucky, but there is no way of predicting this.
Recently I saw this in two gardens and it has made me wonder if others are suffering, from using manure with it, or even potting compost (Vitax had it a while ago).
Last yearI suffered some of this from adding a little of my neighbour’s horse manure to my own compost heaps. Her horses had eaten hay made from grass sprayed with this poisonous weedkiller, which persists. Growth of susceptible vegetables is stunted as the young leaves curl inwards like a fern. Most susceptible are solanums and legumes, also suffering are lettuce (asteraceae) and beet family. Whereas brassicas, cucurbits and alliums grow alright.
The only cure is that soil organisms break it down after about a year. In a heap, it just remains dormant.