Had terrible problems with leaf miner for few years but have found Spinosad based products worked well this season. It's a chemical but I think it's even allowed here in EU for organic crops, not sure about UK. Spray on roots at time of planting and then I usually spray a little bit at the base of the plant no need to spray leaves. Also worked for cabbage root fly, same approach. Cheaper than netting everything. First time in years got a crop from onions and brassicas, hoping the same for leeks this year will try on garlic in Oct. If only I could control the club root.
As an allotmenteer John, I found this very informative. I like the spray device and it covers very well as you say. Can you tell me what variety of onions you're growing in the pots? Thanks in advance.
Hello Elaine, I have grown this onion for or about 20 years now. I seed my own plants every year as you will see by my other posts. You could say it’s re-selected Kelsey.
Hi John I’m sorry to hear that. It’s been a massive problem all over the country. There are whole allotment sites wiped out with it. Hopefully the fungicide sprays we can get will clear the problem for future years.
