Damage to cuke plants from pyrethrin/oil application?

Cocoa, FL

I have cuke plants that are about 4 inches high. I was dismayed to see whitefly and caterpillars on them already. I had some garden safe insect spray, it is pyrethrins mixed with canola oil. The bottle is probably 2 years old. I sprayed the cukes pretty heavily at about 7 am. I also sprayed the tomatoes next to them for good measure. I live in zone 9b, and it's still pretty hot here, but is was cloudy that day. When i checked on them at 6pm, they looked terrible! The leaves were brown around the edges, and some leaves were almost transparent. The tomatoes had a little damage, but not as bad as the cukes. Should i be spraying insecticides and oil late in the day instead? And is it safe to spray baby plants with oil or insecticide or do i have to wait till they're older? Thank you for any advice, i am very frustrated with these cucumbers.

Deep East Texas, TX(Zone 8a)

I ran into the same thing all summer and this fall. The whiteflies are terrible and if I wasn't careful with what I used, it would burn the leaves like you described. Cucumber foliage seems to be more sensitive.

I ended up using Safer soap as an "on contact" killer in the evening and would give the foliage sprays of water to deter the bugs in the early morning. The cucumbers I did harvest were wonderful but it could have been far better.

I think the evening spray would be better and perhaps wait till the plants become more established before using that treatment. Kristi

Liberty Hill, TX(Zone 8a)

I've had a terrible time with leaf miners this year. It seems like if I want to garden I need to hire an exterminator. Sometimes the leaves turned white overnight, the infestation was so bad. I'm sorry to hear you both are having pest issues also.

Deep East Texas, TX(Zone 8a)

Hi Lisa ~ I had my hands over my ears when you mentioned leaf miners. lol
Seems when something different is mentioned, it shows up at my house.
How was your garden this year?

Tiskilwa, IL

My gardening mentor has told me before not to spray plants when they're small or recently transplanted. I'm not sure of the whys and wherefores, but it seems they are more vulnerable then.

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