Tomato flower drop in hot weather

Tomato flowers often drop when days reach about 90°F or nights stay above about 75°F. Dry soil makes it worse, and even moisture helps the plant through.

When we suggest this

• ForecastHighs of about 90°F or more for 3 or more days in a row or nights that stay at or above about 75°F are forecast for today or the next 3 days.
• Your noteYour note: stage is flowering or fruit forming or ripening; or no stage noted yet and planted at least 30 days ago.

What would stop us suggesting it

• When the forecast heat ends.
• When you mark it Done or Doesn't apply. "Doesn't fit my setup" stops it for that plant this season.

What to do

1. Push a finger into the soil near the plant. If it's dry at the first knuckle, water deeply at the base.
2. Expect some flowers to drop while highs are near 90°F. Plants usually set fruit again once it cools, so there's nothing to fix.
3. You can pick fruit that is starting to color and let it finish indoors. In strong heat, fruit left on the vine may ripen orange instead of red.
4. A layer of mulch helps the soil stay evenly moist.

What we can't know

• How moist the soil is at your plants.
• Whether shade or wind at your spot makes it cooler or hotter than the forecast.

Extension sources give day thresholds from about 85°F to 95°F and night thresholds from about 70°F to 75°F; duration matters more than a single hot day. We use 90°F days or 75°F nights for three days in a row, the values most sources share, to avoid tasks for brief heat. The 30-day fallback for plants with a known transplant date but no stage note is an estimate from days to maturity (about 55–90 days from transplant) minus 6–8 weeks from flower to ripe fruit.

Where this advice applies

All US regions.

Any US garden with a run of days near 90°F or warmer, or nights that stay near 75°F or warmer.

In the low deserts and much of the Gulf South, summer heat like this is normal and can last for weeks; many gardeners there time tomatoes to fruit before or after the hottest months. Heat-set varieties hold flowers better.

Exceptions

• Plants you've marked finished for the season.
• Young plants that haven't flowered yet.

Related guide sections

• Growing tomatoes: weather

Reviewed

Sources checked Sept 2026 · awaiting expert review

Gardenplanner research (AI-assisted), pending extension-qualified review

Rule id and version: tomato.heat-flower-drop@1