What Causes My Tomato Flowers to Fall Off and How to Fix It

As a tomato gardener, few things are more frustrating than seeing your plants put out lush green growth and beautiful flowers, only to have many of those blooms wither and fall to the ground. Known as blossom drop, this phenomenon can rob you of much of your expected harvest.

The good news is that blossom drop can often be prevented by making a few simple adjustments to your care routine. In this article, I’ll walk through the most common causes of tomato flowers falling off and give you tips to get your plants back on track for a bountiful crop of juicy tomatoes.

Why Do Tomato Flowers Fall Off?

Before diving into the various causes, it helps to understand what triggers tomato blooms to form in the first place. Tomato plants produce flowers in response to certain environmental cues that signal the plant is healthy and conditions are right to begin fruit production.

The most important factors are adequate sunlight, proper daytime and nighttime temperatures, and consistent soil moisture. When any of these are off, the plant may abort some of its flowers to conserve resources and energy.

While a little blossom drop is normal, heavy drop-off indicates issues in your care regimen. Below I’ll outline the most frequent culprits and solutions.

1)Cold Weather

Tomatoes thrive in daytime temperatures of 70-85°F and nights above 55°F. Cooler weather can cause poor pollination of flowers, resulting in unfertilized blooms that soon wither and fall.

Prolonged cold snaps also inhibit nutrient uptake, leaving plants stressed. Try these tips to help your tomatoes through cool weather:

• Use row covers, cloches, or cold frames to trap heat around plants. Remove during the day when temps exceed 75°F.
• Avoid planting too early in spring when nights may still be chilly.
• Locate containers where they’ll capture afternoon sun and radiant heat from structures or pavement.
• Apply organic mulch around the base of plants to moderate soil temperature.
• Prune away some upper foliage to allow more sun to reach ripening fruit.

2)Heat and Drought Stress

Just as cold can cause issues, excess heat, and drought stress are common triggers for blossom drop. Tomatoes need consistently moist (but not soaked) soil. Under hot, dry conditions, plants shut down non-essential functions like flowering to conserve moisture. You’ll soon notice wilting leaves and dropped blooms.

• Water deeply 1-2 times a week, aiming for 1-2 inches per week (including rain).
• Use drip irrigation or soaker hoses to target soil. Avoid overhead watering.
• Mulch plants to reduce evaporation from the soil surface.
• Provide temporary shade if temps exceed 90°F.
• Mist plants on very hot, dry afternoons to cool leaves.

3)Improper Pollination

Tomato flowers are self-pollinating, but still benefit from air circulation to shake pollen loose within the flower. Lack of air movement can inhibit pollination, causing flowers to wither. Here are some tips:

• Gently shake plants midday to dislodge pollen.
• Use a small electric fan to circulate air around plants for a few hours daily.
• Avoid crowding plants too close together. Give them ample breathing room.
• Consider adding pollinator-attracting flowers near your veggies to draw in bees.

4)Over-Fertilization

Tomato plants need nutrients to fuel growth and flowering, but excess nitrogen from fertilizer can backfire. Rapid, lush vegetative growth comes at the expense of fruit production. Flowers form but soon drop in favor of more leaf and vine growth.

• Use a balanced organic fertilizer according to package directions. More is not better!
• Avoid high-nitrogen formulas (higher first number). Look for even or low ratios like 5-5-5.
• Cut back on fertilizing after the first flush of flowers appears.
• Leach out built-up salts by watering containers thoroughly until water drains from the bottom.

5)Light Deficiency

Like all plants, tomatoes need ample sunlight for robust growth and flowering. At least 6-8 hours of direct sun is ideal. With insufficient light, the plants divert energy into stretching and searching for better light rather than fruit production.

• Choose the sunniest spot possible, even if it requires removing obstructing trees or structures.
• For container plants, move into areas with maximum sunlight as conditions change.
• Prune back dense foliage, especially toward the base, to allow more light penetration.
• Use reflective mulch around plants to bounce more sunlight up into the plant canopy.
• Supplement natural light with grow lights if unavoidable shade exists.

6)Disease and Pests

Various tomato diseases and pests can take a toll on your plants, causing stressed, undernourished plants that drop flowers as a survival mechanism. Common culprits include early and late blight, verticillium wilt, tobacco mosaic virus, hornworms, aphids, and whiteflies.

• Remove and destroy any plants showing disease symptoms immediately to avoid spread.
• Control insects through natural means like insecticidal soap, neem oil, BT spray, and handpicking.
• Use preventative measures like crop rotation, resistant varieties, and proper plant spacing.
• Keep the garden free of debris and weeds that harbor pests.

7)Fluctuating Soil Moisture

Irregular watering that allows the soil to alternate between very wet and very dry will inevitably cause blossom drop. Tomato roots thrive on consistently moderately moist soil.

Uneven moisture causes stress as roots struggle to absorb nutrients and water. Help your tomatoes avoid this roller coaster by:

• Checking soil moisture daily and watering as needed to maintain even moisture 2-4 inches down.
• Use drip irrigation on a timer or soaker hoses for consistent application.
• Mulching to buffer soil from drying winds and hot sun.

8)Excess Fruit Load

If your plants successfully set more fruit than the plant can support, it will begin aborting flowers to redirect energy to existing fruit. This is most common in very small varieties or overly dense plantings. Solutions include:

• Providing extra support for heavily weighted vines with cages, stakes, or trellises.
• Thinning fruits when they are marble-sized leaves one fruit per cluster.
• Choose larger, vigorous varieties suited to your space limitations. Compact types need wider spacing.
• Avoid overcrowding plants in an effort to squeeze more into limited space.

Tip of the Iceberg

The issues covered above represent the most frequent causes of tomato blossom drop, but other factors like nutrient deficiencies, herbicide drift, root damage, and extreme weather can also come into play depending on your growing conditions.

Pay close attention to your plants and make note of any changes that precede heavy flower drops. Being vigilant and making timely interventions is key to getting your plants back on track.

When to Worry About Tomato Flowers Falling Off

A few dropped flowers on your tomato plants is normal and not a major concern. But if your plants consistently develop flowers that wither and fall before fruit can form, it’s time to take action.

• If temperatures have been fluctuating above 90°F or below 60°F, blossom drop is understandable until conditions stabilize.
• Seeing scattered flowers fall is expected, but consistent drop across whole plants indicates a larger issue.
• If blooms are falling off in large numbers, be proactive about adjusting care practices before yields are further affected.
• Take note if flower drop occurs at particular times – early morning could signal cold damage while mid-day points to heat stress.
• Preventative measures will always be more successful than reacting once substantial drops occur. Don’t wait too long before addressing the problem.

Caring For Tomatoes After Blossom Drop

Losing some blossoms doesn’t have to spell disaster for your tomato crop. Here are some tips for getting plants back on track after significant flower drop:

• Remove fallen flowers and any damaged fruit to improve plant energy.
• Continue optimal care practices – consistent watering, improved support, and pest management.
• Shield plants during heat waves and cover during cold snaps to prevent further flower loss.
• Lower nitrogen levels in fertilizer to encourage fruiting overleaf/vine growth.
• Prune back leggy growth to stimulate new flower production closer to the main stems.
• Monitor for signs of disease or nutrient deficiencies and treat accordingly.
• Wait for a flush of new blooms, then assist pollination by shaking and vibrating plants daily.
• Harvest existing fruits promptly when ripe so plants redirect energy toward ripening more.
• Talk to local experts about the best late-season tomato varieties to plant if time allows.

As long as your tomato plants remain healthy, they should re-blossom and produce new flowers in 4-6 weeks after losing an initial set. Don’t abandon plants too quickly – with a little TLC, you may still get tomatoes later in the season.

I hope this article helped you figure out What Causes Tomato Flowers to Fall Off. Take these preventative measures, and you’re sure to see your tomato plants bursting with ripening fruit. No more disappointment of flowers falling off – just the happy harvest of sauce-worthy, sandwich-slicing tomatoes!