Asked on Jul 28, 2013

Why are my cucumber and cantaloupe leaves spotted?

This is my first experience of having a raised bed garden. I chose a cinder block garden and am trying my best to make it an organic endeavor. I made my own soil mix consisting of compost/manure, organic gardening soil, peat moss, and organic soil conditioner.
In one of my garden beds, I planted lemon cucumbers and cantaloupes from seed. Everything had been going well. The cucumbers hadn't produced any flowers yet but they were growing and climbing their trellis. The cantaloupe had developed blooms. Two days after I made this wonderful observation, I watched my bed become destroyed. I've researched and I can't figure out what the problem is.
This was my cleanest bed. Butterflies and bees visited frequently. I have marigolds planted around the bed. I used Epsom salt once because I read that the soil could be missing a nutrient that was turning the leaves yellow and that it would boost fruit production. I don't know what else to do. Even if I lose this crop, I still want to know what is wrong before I plant anything else in there for the fall.
Thanks!
Libby
This is my bed for the lemon cucumbers and cantaloupe.
Cantaloupe leaves staked on two trellesis.
Lemon cucumber leaves.
Blooms on the cantaloupe.
Cantaloupe leaves staked on two trellises.
This is the beginning of the spotted, yellow-leaf action. Now, all of the cantaloupe plants are affected and the bottom rows of cucumber plants.
  8 answers
  • Douglas Hunt Douglas Hunt on Jul 29, 2013
    I am not a vegetable expert, Libby, but it looks like you may have downy mildew. Compare the photos here: http://www.extension.umn.edu/gardeninfo/diagnostics/vegetable/cucumber/leavesspots.html
  • Thanks,@Douglas Hunt ! It does look a lot like that. It's been raining so much here too and when I went to Lowes today the garden center manager told me not to water it and wait a few days to see what happens and go from there. In the meantime, I'll look for an appropriate fungicide.
  • Catherine Smith Catherine Smith on Jul 30, 2013
    Everybody seems to be having lots of problems with various mildews and fungal problems this year and probably because of all the rain. You might also want to take some samples to your local extension office, they should be able to diagnosis exactly what you're dealing with and possible solutions. If in fact you are dealing with downy mildew, do not replant cukes, loupes etc back in that area of several years, as the fungal spores get into the soil. Some other types of veggies should do well, or some type of cover crop to help "wear out" the fungal spores. Besides a cover crop will help replenish the nutrients in your soil.
  • Darlene Mapes Darlene Mapes on Jul 30, 2013
    My cucumber plants and Zucchini are also suffering from this. :(
  • Thanks, @Catherine Smith. It seemed to happen so fast but I definitely want to make sure the bed is okay for future crops. Thanks for letting me know. I was planning to get my soil tested before fall so I might as well do that now. Thanks again!
  • Faith Silva Faith Silva on Aug 08, 2013
    The Farmers' Almanac has a lot of handy tips. I had a problem with blossom rot on tomatoes once and found out that all I had to do was pour MILK around the plants. Who knew?!
  • Anascreations4u Anascreations4u on Aug 25, 2013
    Well, I hope you solve your problem. You really solved mine!! Lemon cucumbers! I couldn't understand why my cucumbers were yellow from the very start!! Good luck!!
  • Glenda D Glenda D on Dec 26, 2013
    blossom rot you need more calcium. As for the mildew. I had the same problem. Yes it is because they are too wet. I was watering with a sprinkler and that started the whole mess, I changed to a soaker hose but the mildew never went away. I still had lots of Zucchini but had to be sure I picked them before the blossom started to rot. Have you heard of Jerry Baker's Books. I have one it has a recipe for getting rid of the mildew, but unfortunately it keeps coming back so I had to use his recipe every 2 weeks just to keep the mildew off the plants. It got to be a real pain. I would give you the recipe but it's down in the garden shed and it is 10:45 pm and I don't want to walk out there tonight. I will try and remember to get the book and write out the recipe for you. It uses household items, I think 1 was baby shampoo and maybe mouthwash. Can't remember. will get it tomorrow.