i dont provide a greenhouse but I suspect with all the rain we have received that might contribute. I am in high ground soil which may allow for good drainage and I am on a slight alkaline scale of the ph .Tomatoes and squash have done well, and cucumbers start well but will have cycles of green to browning . I f watering is needed, I will water earlier in the day, to late and they sit in water at night that might create a fungus.?