Sometimes, plants do weird things. You’re watering them, making sure they’re getting sun, they’re cheerfully growing away, them, BOOM, all the leaves turn yellow and fall off. Or they set flower, you’re waiting for the vegetables to come, and they just never do. Or, bug attack. Or mildew attack. Or, on and on we could go. Possible explanations for scenarios like these include “black thumb,” or “wrath of God.” But should you care for a slightly more scientific explanation, I can help!  Send your q’s to spadespatula@gmail.com, and I’ll answer them right here on the site. For our first installment we have…

The Case of the Yellowing Cucumber Leaves

The matter for consideration:

“hi plant doctor. what causes cucumber leaves (or others) to yellow? our cucumbers are thriving and full of little baby cucumbers (and one big one so far that we ate this weekend). but in the last few days i’ve noticed the leaves yellowing, particularly the ones close to the ground. need more fertilizer? also it surprises me how thirsty these tomato and cucumber plants are once they get big. they need ridiculous amounts of water to keep the leaves from getting wilty.”  — Jason, Providence, RI

Wanna hear my answer? Click on through!”

Dear Jason:

There are several reasons the cucumber leaves could be yellowing. The first is, as you guessed, a bit of a nitrogen shortage. A little fertilizer should green things back up (if that’s the problem). Another possibility is that you might be overwatering. If you’re watering just enough to keep them from wilting, that’s probably not the issue, but maybe. You could try cutting back a touch and see what happens. The final thing — it could just be natural aging of leaves. The leaves at the bottom are the oldest and they have to die at some point. But if it strikes you as a weird yellow rather than a normal “I’m-old” yellow, then it’s one or two. Easiest thing — just try fertilizer and see if that doesn’t fix it.

Want to ask a question of your own? spadespatula@gmail, and I’ll see what I can do for you!