I have been trying to figure out what’s wrong with my fucking zucchini. Two of the three plants I’m growing had yellowing, browning, and eventually, dying leaves. This is not a new problem, I’ve never had great production from my zukes, and never understood how folks have enough to make bread or to give away. Hence my fucking zucchini frustration. This summer has certainly been the worst so far. See my previous post for pics and descriptions: Something is Going on with the Zucchini.
That being said, this summer I’ve focused on solving this issue, and have finally made some progress. As explained in my earlier post, I used a generic vegetable fertilizer and didn’t see any results after a week; the leaves actually got worse. So I tried the other suggestion I’d found through some research: magnesium. Using a solution of Epsom salt and water, I treated the base of each of my cucurbits, and then left for a camping trip.
And SURPRISE!!! When I returned after several days, the results are significant and positive!
Before Mg 
One week after Mg
I feel pretty confident that the Epsom salt made the difference. A week before the Epsom salt treatment I used a generic vegetable fertilizer (Miracle-Gro Tomato Plant Food 18-18-21) on all the veggie plants, and while everybody definitely got a little greener and bigger and healthier looking, the fertilizer didn’t even make a dent in the zucchini leaf problem. One week post Epsom salt treatment, however, and the results are clear and definitive.
Before Mg 
One week after Mg
There have been other improvements as well. I read that the magnesium is required for uptake of nutrition, so an Mg deficiency prevents the roots from taking in the necessary good stuff. Since I did the fertilizer a week before the Mg, I was able to see that the fertilizer didn’t really do much to improve the zukes. Besides the yellowing and browning leaves, I had also noticed that the plants were producing very small and slow growing fruit. I even noticed some end rot:
These two never got any bigger than this, after pollinating three weeks before.
My previous experience with summer squash is that once pollinated, the fruit grow to harvest size in just a few days. So a zuke this tiny three weeks after pollination is an indication of something wrong.
The great news is that this problem seems to be fixed as well! One week after Mg treatment, and check out these stupendously phallic bad boys:
More good news came from the yellow squash and the cucumbers. My cukes and crooknecks had been growing, but slowly. I had a gazillion flowers, suspiciously few fruit, and the tiny little potential squashes were pollinating but not setting. A squash that didn’t pollinate completely will stay very tiny (tinier than in these pics below), but will also become soft. These squash obviously pollinated, were firm, and even grew a little bit, but they never got any bigger than this, even two to three weeks after the bees knees did their sex magic.
But one week post Mg treatment, and voila!! Cucumbers AND squash!!
In past years I’ve always had lame harvests of squash and zucchini, and always wondered how others got so much! Now I know why. I suspect I’ve had this magnesium problem for a while, but never carefully and intentionally tried to fix it. Partially, that is because in previous years I’ve had massive pest infestations, and have usually associated these issues with pests. This year, however, I’ve had few pests, so have had the time and brainspace to do some goddam sciencing!!
The Pottymouth Gardener 