Why Pepper Plants Drop Their Flowers

Peppers are fussier than tomatoes about this

Both crops drop flowers in bad weather, but peppers have a narrower comfortable band, and the limits are on night temperature as much as day.

University of Maryland Extension puts flower and small-fruit drop at night temperatures below 60°F or above 75°F, or day temperatures above 95°F.

That is a tight window. A night in the high 50s is enough, which surprises people who associate flower drop with heatwaves only. Illinois Extension adds that below 50–55°F at night, pepper plants grow slowly, leaves may yellow, and flowers drop.

Why early-season drop is normal

The first flush of flowers on a pepper transplanted out in late spring very often falls off, because nights are still below the threshold.

This is not a failure and it needs no intervention. The plant will flower again. Many experienced growers pinch off those first flowers anyway, so the plant puts energy into roots and foliage before it starts carrying fruit.

If your peppers dropped every flower in June and are setting fruit in July, nothing went wrong.

Midsummer drop is the same mechanism, inverted

A run of days above 95°F, or nights that stay above 75°F, will produce the same result at the other end of the season. As with tomatoes, high temperatures interfere with pollination, and the plant sheds flowers it cannot support.

The response is the same too: shade cloth during extreme heat, consistent deep watering, and patience until night temperatures fall.

The causes you control

Water. Maryland notes that dry conditions cause blossom drop, small fruit, and blossom end rot — peppers get blossom end rot for the same reason tomatoes do. Water deeply and consistently, and mulch to stop the swings.

Nitrogen. As with tomatoes, excess nitrogen pushes leafy growth at the expense of flowers and fruit. A big dark-green pepper plant with almost no fruit is usually overfed rather than underfed.

Sun. Peppers want full sun. A plant shaded for part of the day flowers less and holds less of what it sets.

What will not fix it

There is a persistent belief that Epsom salts improve pepper fruit set. Magnesium deficiency is a real thing and does occur in some soils, but it is not the reason flowers drop on a well-fed plant in a hot week, and routine Epsom salt application to soil that does not need magnesium achieves nothing.

The same applies to hand-pollinating with a brush. It helps when the obstacle is genuinely still air — under cover or on a sheltered balcony — and does nothing when the pollen has been compromised by temperature.

The realistic expectation

Peppers are slower to set than tomatoes and more sensitive at both ends. In a season with a cool spring and a hot midsummer, the productive window can be narrow, and a plant that looks stalled for weeks will often crop heavily in late summer once nights settle into the 60s.

Before changing anything, check what your nights have actually been doing.