How to tell it's blossom drop
A dropped eggplant flower leaves a clean, pale scar on the stem with no tiny fruit behind it, which means the flower wasn't fertilized. A few dropped flowers here and there is common. The concern is a plant that drops nearly every flower for a couple of weeks. Look at whether the drop comes in waves that line up with the weather, such as a cool spell after or a run of very hot days. A plant that otherwise looks healthy, with green leaves and no pests, points to growing conditions rather than disease. Also note how many bees you see on the purple flowers.
Why it happens
Temperature is the usual cause. Washington State University Extension notes that, with or without insect pollination, eggplant flowers drop without setting fruit when temperatures are above 95°F or below 60°F, and University of Maryland Extension says eggplant doesn't set fruit well until night temperatures stay above 55°F. Early in the season, cool nights are usually to blame; in midsummer, heat is more often the cause. Eggplant is a tropical crop, so a plant set into cold soil may stall and drop its first flowers.
Water stress comes next. WSU suggests 1–2 inches of water a week and evenly moist soil, noting that uneven moisture leads to poor production; containers dry out fastest. Pollination plays a part too. Eggplant flowers carry both male and female parts, but research cited by WSU found that fruit set improves with bee activity, so plants on a balcony or in a yard with heavy spraying may set poorly. Too much nitrogen pushes leaves at the expense of flowers and fruit, and Maryland lists excess nitrogen among the causes of poor blossom set.
What to do now
Water deeply so the soil a few inches down stays moist, and add 2–3 inches of organic mulch once the soil is warm. Hold off on nitrogen until fruit starts to form; WSU suggests one of about 1½ teaspoons of 21-0-0 per plant at that point, spread on the soil near the base. If bees are scarce, touch the center of each open flower with a small, soft brush in the morning. In very hot climates, a spot with late-afternoon shade can help. Once temperatures settle, healthy plants usually start setting fruit again.
Next season
Next year, wait to transplant until at least 2–3 weeks after your last spring frost, when the soil has warmed to about 60°F, as WSU recommends. Black plastic laid over the bed a few weeks before planting warms the soil; WSU suggests removing it at planting time. Plant flowers nearby for bees and keep insecticides off open blooms. Pick fruit while the skin is still glossy, since Maryland notes that plants left with unharvested fruit tend to slow their flowering.
Before using any product, read the whole label. It must list the crop you’re treating, and its directions on amount, timing, protective gear, bees and days before harvest are legal requirements. If this page and the label disagree, follow the label.
Growing it again? When to plant eggplant for your ZIP code
- Why do my pepper plants keep dropping their flowers?Pepper flowers usually drop from stress: nights below 60°F or above 75°F, very hot days, uneven watering, or too much nitrogen. Most plants start setting fruit again once the weather settles.
- My tomato plants are full of flowers but no fruit is setting — why?Tomato flowers often drop without setting fruit when nights stay above about 70°F or below 55°F, or days top about 90°F — warm nights are a common cause in midsummer.
- What does drought stress actually look like, and how do I know when to water versus when something else is wrong?Drought stress progresses from midday wilting to all-day wilting, leaf curl, and eventually aborted fruit and flowers — the key is catching it before the plant has been dry long enough to abort reproductive structures.