Cucumber leaves drying and cracking; cucumbers die before fully formed
Hi, I've been having some trouble with my cucumbers (dragons egg and chicago pickling varieties). For background, I'm in Burbank, CA and so far this Summer hasn't been very hot at all. At most it's been in the upper 80s which hasn't happened much so far. Although that is starting to change. As seen in the photos below, the leaves tend to get very dry and brittle. In the worst cases there are dry veins going up the stems as well. Most of my plants are continuing to exhibit new growth but the older leaves are starting to crack. I've also only had about one good cucumber from either plant. The rest tend to get about an inch long, start turning brown near the flower end and then just shriveling up. I tried adding some potassium and phosphorus rich fertilizer hoping it was just a deficiency thing. The mixture I was using was about 3-5-5 or something to that affect. Perhaps it wasn't enough. Also where they are is sunny but is a bit more shaded by the afternoon but they are by no means completely in shade for half the day, just not direct sun all day. I figured this was best for them anyway. Despite all this, there is new growth. I just want to make sure that new growth doesn't become plagued with the same issues as the old. Thanks! -Mark
Certified GKH Gardening Expert
It is a deficiency, but it is a calcium and magnesium deficiency. This can be corrected with Dolomitic lime. This is nothing more than calcium carbonate, and magnesium carbonate. This will also regulate the pH of the soil.
Adding more phosphorous likely will not help. Use the dolomitic lime, and you will see an improvement. Now, cucumbers like cooler temperatures. 80's is still quite high for cucumbers, at least when it gets above 85. They will be reluctant to fruit at higher temperatures.
I would also add a little wettable sulfur... It appears to also have the start of a fungal infection. This will take care of it.
Thanks! Unfortunately I live where I live. I won't see the 70s until the fall. That might be a better time to plant cucumbers. There's less sun but at least the temps will be more beneficial for their fruiting.