Tomato Blossom Drop

It is so disappointing to watch anxiously to see the first tomatoes forming and then see the blossoms missing. After all, they are not the first thing in the garden to ripen. So when blossoms drop, leaving little or no forming fruit, I (have to go to the Farmer's Market....) to have tomatoes to go with my basil and avocados.

I am starting to understand why I have more blossom drop than when I planted random plants around the townhouse grounds where I previously lived in the Sierra Madre area of No San Gabriel Valley. One of the causes is lower than 50F nighttime temps. The plants I had at the townhouse grounds had tree protection.

Once the fruit starts to get going, and it warms up, the plants start doing better. Also, some varieties are hardier than others. Cherry varieties seem to have less of this problem However, long spells of high heat can affect the blossoms.

Here is a summary of causes -

• Temp stress - higher than 85F daytime, higher than approx 70F at night and lower than 50F at night.
• Humidity - too low or too high. This is not typically a concern in our area.
• Too many blossoms - some loss is expected.
• Pollination - well, you know, not enough bees.
• Watering - deep water 1 - 2 times a week, do not water shallow.
• Over feeding - feeding lightly at planting and again when fruit starts to ripen is enough. Applying too much nitrogen in our efforts to make robust plants, can cause our own problems.
• Pests - control white flies, aphids, etc.
• Pruning - cut back some of the side shoots to force more energy into the blossom clusters.