Every growing season many gardeners wait to see their pepper plants in full bloom but instead often find their blossoms falling off. What causes flower drop in pepper plants?
Pepper plant flowers usually drop due to environmental conditions, such as strong wind and rain, temperature fluctuations, changes in humidity levels, imbalanced soil nutrients and fertilizers, over-watering or under-watering, and insufficient lighting.
In the rest of the article, we’ll elaborate on how these factors affect flower production and lead to flowers dropping. We’ll also give you some tips on how to avoid these problems.
Conditions That Cause Pepper Plant Flowers to Drop
Flowers can’t survive in strong winds and extreme rain. However, if there’s no wind or pollinators, pepper plants can’t pollinate, and their blossoms could drop. This is often a problem for folks who grow their pepper plants indoors.
One of the most common causes of pepper plant’s flowers dropping is extreme temperature fluctuations, as pepper plants are susceptible to both hot and cold weather.
Peppers plants grow best and bear fruit in specific temperature ranges. The ideal daytime temperatures for hot pepper varieties are up to 85 degrees Fahrenheit (29 degrees Celsius) and 70-80 degrees Fahrenheit (21-26 degrees Celsius) for Bell pepper varieties. Nighttime temperatures should be between 60 and 75 degrees Fahrenheit (15 to 24 degrees Celsius).
Most of the time, exposing pepper flowers to higher or lower temperatures for one or two days/nights won’t cause big problems. But extreme fluctuations, such as 105 degrees Fahrenheit (40 degrees Celsius) during the day or less than 50 degrees Fahrenheit (10 degrees Celsius) at night will immediately induce flowers to drop. Heat waves and cold snaps can stress out the plants, leading to the dropping of leaves and flowers.
Pepper plants are a little picky when it comes to humidity levels and prefer 50 to 70 percent humidity to thrive. When the air lacks enough humidity, the pepper plants have to breathe out excessively to absorb more water from the air.
This increased concentration on breathing diverts the plant’s attention from growing and keeping its flowers.
On the other hand, high humidity makes pollen sticky, reducing the chances of pollination, which is essential for turning flowers into pepper pods.
Over or Under Exposure to Sunlight
Pepper plants need ample light, particularly during the early stages of flowering. They need to be planted 18 to 24 inches (46 to 61 cms) apart in a sunny place to receive light equally on their leaves.
Pepper plants should be exposed to six to eight hours of sunlight every day. They also need four hours of darkness. That is because the natural day-night cycle has a considerable impact on the pepper plant’s flowering, especially if you keep them in a greenhouse.
Underexposure to darkness can bring about physiological problems, including flower drops. Being in a dark environment for a few hours everyday gives them enough time to focus on flowering.
Soil Nutrient Levels
If a pepper plant receives inadequate or unbalanced levels of nutrients, like too much nitrogen, the plant will drop its flowers. The best soil for growing peppers has a pH of 6.2 to 7.0. However, peppers can tolerate acidity levels up to 7.5.
The soil should contain enough organic matter to help it keep moisture, which is crucial for flower production. It also helps keep the beneficial bacteria in the soil since they improve nutrient uptake.
It also has to be well-drained and contain a loamy good quality potting mix to prevent the soil from getting soggy. And one way to help the soil retain moisture is by putting mulch a few inches down around each plant.
No matter how rich your soil is, it needs a well-balanced mix of nutrients in the form of fertilizers to prevent it from dropping its flowers.
Nitrogen is an essential ingredient, which you can provide using compost or organic matter. During the early stages of planting, peppers need high levels of nitrogen to help them grow leaves. But when they start to flower, their need for nitrogen reduces. So, the timing of when to apply what nutrient for pepper plants is important.
If there isn’t a balance among nutrients, especially nitrogen and phosphorus, the flowers will fall off. Nitrogen is necessary for foliage growth. So, when the nitrogen levels are high, the plant focuses on growing leaves rather than flowers which leads to bushy plants with no flowers.
Over- and underwatering can lead to many problems for your pepper plants, including blossom drop. The soil needs to be moist but not soggy. So, only water the plant when the top two to three inches of the soil are dry.
The watering doesn’t need to be frequent; do it less often but deep enough to make sure the soil remains moist for a long time.
Tips for Preventing Pepper Plant Flowers from Dropping
Flower drop is sometimes due to environmental factors that you can’t avoid or control. However, there are some measures to minimize the risk of blossom drop.
It’s essential to have a well-balanced nutrient mix in your soil. You can buy a tester to measure the nitrogen and phosphorus content of your soil. You can use a balanced fertilizer to give the soil all the necessary nutrients, but if the soil test shows it has enough phosphorus, choose a fertilizer with less or no phosphorus.
As we mentioned, timing is essential for adding soil nutrient supplements. Make sure the soil is ready for planting by adding compost, a general fertilizer, and 30 percent of the nitrogen before planting. Add 45 percent of the nitrogen two weeks after planting. And the last 25 percent is for the final weeks when the harvest is coming to an end.
Add phosphorus and potassium to the soil instead of nitrogen before the plant flowers because they encourage flower growth and healthy cell development to withstand stress.
Magnesium is also a critical nutrient for flower-bearing. If the soil test shows a magnesium deficiency, use a tablespoon of Epsom salts, mix it with a quart of water and pour it on the base of the plant.
In hot areas with long summer sunlight, you should plant your peppers in spots where they can receive ample morning light and are shaded during the afternoon sun, which is hot and damaging to flowers. If you don’t have such a spot, hang a shade cloth over the plants to protect the flowers.
And if you live in places where the temperature can drop below 70 degrees Fahrenheit (21 degrees Celsius), you might consider moving your plants indoors or adding heat lights or pads to keep your plants comfortable.
If you don’t get enough pollination due to a lack of wind or natural pollinators, you can hand-pollinate the plants. Use a Q-tip or a brush and gently rub them against the flowers to distribute pollen. You could also gently shake the plants to encourage pollination.
Raise Humidity Levels
Misting the plants with a water spray a couple of times during the day is a good idea to provide humidity. However, if there’s a risk of fungal disease, don’t use this method and add mulch to the soil.
Flower drop is a common issue in pepper plants, discouraging and frustrating gardeners. A plethora of reasons may be responsible for this issue. They include:
- Humidity fluctuations
- Temperature changes
- Too much or too little fertilizer and the incorrect mix of soil nutrients
- Overwatering and underwatering
- Lack of sunlight and dark hours
Many of these factors are easy to control. For example, you can improve humidity by spraying water on the plants a couple of times a day. Run soil tests to make sure the soil has enough nutrients and avoid using nitrogen right before flowering.