I have about half a dozen very big pots which I used last year for growing tomatoes but I didn't empty them before winter struck. When I turn the soil over, I can still see plenty of fine tomato roots.
Can I re-use the same soil again this year for tomatoes, just turning it over and mixing some more compost in, or do I risk tomato blight if I don't rotate the planting?
Would it be worth mixing in some Derris powder to avoid blight?
Thanks!
BFD
If it were me I would add it to my compost heap rather than reuse.
The compost will be exhausted but could be OK if you used a very careful feeding regime, after all you can grow toms in straw bales and feed/water them correctly you can get a great crop.
As for derris, that is an insecticide and not a fungicide. Blight is a fungal problem and can be prevented to some degree by using things such as Bordeaux mixture or Dithane. Repeated treatments are required during the year depending upon rain and weather patterns.
There are no treatments available to cure it once your plants have it I am afraid.
HTH
Jerry
From direct experience, I can comment that using spent tomato compost again for tomatoes is not beneficial. Apart from the exhaustion of nutrients, there is a large risk of undesirable viruses etc which can fell all your plants instantly. I reuse my spent compost as seed material, then it goes onto prepared beds for non tomato use.
Same as above sounds good advice
Dan if i were you i would spread the soil around the garden, we always do that and start afresh it really is worth it. Good luck with your tomatoes.Rosebud.
Thanks all for the good advice, that's what I will do then!