The dreaded blossom rot

Asked July 27, 2020, 4:06 PM EDT

Well, my squash and cucumbers have blossom rot. Thus far, I’ve watered the soil weekly with a liquid blend of Fox Farm Bloom Booster, Bu’s tea, and dissolved Epsom salt. I’ve also added a single dose of dissolved Tums capsule in some Fox Farm Ocean Meal soil as a side dressing. This year I used store bought potting soil and mushroom compost but I believe the soil is pretty poor overall. One suspicious thing to note is that some cucumbers and squash are making it through while others fall and rot off the vine. Do you have any suggestions or resources to attend to the issue? Is it a lost hope?

Washington County Oregon

1 Response

If you are currently watering just once a week, it's very likely the tomato plants are short of water.

Unfortunately, the supplements you've added to the soil won't work if the soil is inconsistently moist. Tomatoes growing in containers are much more likely to have blossom end rot (BER) than are ground-planted tomatoes.

Then, too, the recent sessions of hot, windy days with clear skies are drying out all plants faster than gardeners realize.

Adding calcium may help only if the soil has low calcium and only a professional lab test can tell you that. Consider sending a sample to nearby A&L Labs to request a soil test for your vegetable garden which will include recommendations; they can also suggest how to sample. (503-968-9225)

But first, read these publications:

A. "Blossom End Rot" - To download, go to and click pdf

B. "Grow Your Own Tomatoes and Tomatillos" - Go to
and either click 'pdf' to download the pdf or click 'view online'

The issues with the squash and cukes is entirely different, and are due to the following:

1. Excess heat (prevents fruit set) -- Temporary shade may decrease the numbers of failures or not.).
2. Lack of effective pollination - You can be the bee: To do so, every morning take a small artists paintbrush to transfer pollen from the male flower to the large sticky peg in the center of a female flower. (See "Hand Pollinating Squash" [also works for cukes] -