Understanding why your lemon tree won’t flower can be complex if you’re a novice to fruit tree cultivation. There are several possible explanations for this issues, including environmental factors, improper pruning, not enough sunlight, cold weather, pests and diseases. Contrarily, a lack of fertility or removal of too much foliage may also be to blame. Herein we discuss why a lemon tree may not flower and how to diagnose the problem.
The most common reason why a lemon tree doesn’t flower is lack of pollinators. Citrus trees are pollinated by insects, most notably honeybees. If there aren’t enough bees present to transfer pollen from flowers to flowers, the plants won’t reproduce. Additionally, for lemon trees specifically, the male and female flowers must be open simultaneously for pollination to occur. Some gardeners attempt to intervene by using a small paint brush to transfer the pollen.
If your garden doesn’t attract local pollinators, or if the flowers open at different times, the lemon tree may not flower. Exposure to cold weather can also cause the buds to drop without blooming. Lemon trees thrive in warm and temperate climates, and cannot tolerate frost. If the tree is exposed to temperatures below 55F or 13C, it may not flower.
Insects, such as mites and aphids, can also be a nuisance in the garden. These pests can suck the plant’s sap and eventually reduce it’s health, which can prevent it from flowering. Diseases, such as root rot, can also interfere with the reproductive process. Furthermore, if you give the tree too many high-nitrogen fertilizers it can generate lush foliage at the expense of flowers.
Continual pruning can also cause a lemon tree not to flower since the reproductive buds tend to be located at the ends of branches. If too much of the tree is removed, the buds will not have the necessary resources to bloom. To prevent this from occurring, prune only the branches which interfere with walkways, or which obstruct your view.
Environmental Factors
Above all else, it’s important to remember that warm climates are essential for bloom and fruiting. Although citrus can grow in colder temperatures, they don’t respond well to heavy frosts. If there’s a hard freeze in your area, it’s best that you move your tree indoors during such events and reintroduce it outdoors as soon as possible. Additionally, too much water or humidity can also impair flowering. The trees need soil and atmosphere to dry completely before two and a half inches of water is re-applied.
Diagnosis of the Issue
Diagnosing a lemon tree is difficult but can be managed with the help of an arborist or other expert. If you suspect the problem is environmental, take a look at the tree’s location to ensure it’s not being exposed to cold or wet weather. Also test the soil to ensure it has the correct pH and mineral levels. Consider purchasing a soil test kit at your local garden center if you suspect the soil isn’t optimal.
If you think the issue is related to pollination, you may need to create an artificial environment. To do so, use a small paint brush to collect pollen from the male parts of the flower and transfer it to female parts. Set up a bee water supply near the tree to help attract pollinators.
Finally, if you believe the problem is caused by pests or diseases, look out for signs with caution. The most common signs of pests such as mites or aphids include curling leaves, discolored patches, and webbing. If you spot any signs of pests or disease, treat the tree with insecticidal soap or chemical sprays recommended by your local Garden center.
Pruning
Pruning is an essential part of citrus tree maintenance but must be done with caution. If too much foliage is removed from the existing branches, young, flowering buds may be sacrificed. Be sure to cut only dead, diseased, or obstructive branches, then provide the tree with additional fertilization, to encourage healthy development and flowering.
Fertilization
Although citrus trees are relatively hardy, they need sufficient nutrients to continue flowering and producing fruit. An excess of high nitrogen fertilizer can easily push the tree into a vegetative growth and cause the flowers to drop. To prevent this, be sure to use a low nitrogen fertilizer that is primarily composed of phosphorus and low-levels of potash.
Irrigation
Supplemental watering is important, especially when the weather is dry. Citrus trees need plenty of moisture while they are blooming and take in the most water one week before and one week after flowering when their flowers open. Avoid irrigation during their flowering and fruiting stages, as it can cause the flower to drop prematurely.
Temperature Control
Lemon trees can withstand a range of temperatures but will struggle to flower if exposed to cold temperatures. Extreme temperatures and hard frosts can cause the blossoms to drop, reducing the chances of fruit. To avoid this issue, bring the tree indoors during winter and reintroduce it outdoors in the spring when the temperature warms.
