Lao note the edges of the leaves. I am a new veg. gardener & worried.

I need to know what to buy & how to apply. Think I have some nitrate sulphate but not sure what it does. Your advise is appreciated.

I would suggest googling growing cucumbers and tomatoes in containers. You are sure to find a wealth of information. Sorry I have no experience with this. There is a lot involved, container size, proper growing medium makes a big difference on fertilization requirements.

Are you talking about the white splotches on the leaves? I see 2 of them in the picture although there may be more. Those look like caterpillar webbing/cocoons. They just wipe off.

The color of the new growth is great, no additional nitrogen needed. The older, paler, yellower leaves are from inconsistent soil moisture levels/watering. That is a common problem when using containers, especially when the container is too small for the plant's needs.

So exactly what and how much have you fed them, what is the size of the container, the name of the variety, and the mix in the container?

Dave

That's what those spots looked like to me. Webbing/cocoons. But the OP said it looked like mold. Brownish edges around older cuke leaves is normal for me. Nothing really wrong there. Some minor stress.

the narrow white edges are likely due to water shortage a while ago.