If you are growing your own onions from seed it's probably a good time to get them in this week for transplanting at the end of October. We're growing this variety Non Cooler
as they store for a long time without the need for cold storage. The seeds will need a lot of watering to get them started and establish a root system but once on the go they are fairly maintenance free.
Also for this month it's time to get your garlic in the ground so it can establish well before it shuts down for the winter. Go easy on the fertiliser for the time being as you don't want too much top growth before winter but once spring restarts growth give it plenty of feeding in a high phosphorus & potassium fertiliser like composted chicken manure. If using black plastic mulch whip that off in the spring and apply your fertiliser.
It's still time to seed daikon, we mostly grow small to medium sized daikon as they are easier to use without having to eat daikon for days at a time but this year we'll also be growing a lot of Takuan daikon that are long and very slim to aid drying. The takuan variety from Tohoku Seeds
was really easy to grow last year, dried quite quickly and produced some lovely pickles. Bonus if you have Gardenia growing as you can use the seed pods to colour your takuan pickles yellow naturally. It was also good in Kiriboshi daikon (dried daikon) and was absolutely awesome when roasted fresh.
Depending on area you also might just about be able to squeeze a crop of ingen, either vine or bush type in but if you get cold early there might not be time.
Autumn zucchini probably should be planted this week to have a long enough harvest time before the frosts finish them off and for the rest of this month carrots can be sequentially seeded to provide a continuous harvest through the winter. Also now is the ideal time to start seeding turnips and rutabaga as they will start to mature as temperatures start going down.
It's also time to get autumn salad seeds on the go as hopefully by the time they get large enough the humidity and night time temperatures will have declined.