I have two azaleas that failed to form buds this spring. The plants don’t seem diseased. What happened?
Both these azaleas have flowered well in the past. They are in an area with healthy rhododendrons and a tall deciduous orange azalea that is also healthy. The foliage on the azaleas that failed to bud is healthy.
Azaleas can fail to bloom due to a variety of factors, including:
- Improper pruning
- Inadequate sunlight
- Poor soil conditions
- Incorrect fertilization
- Insufficient moisture, particularly during bud formation
- Damage from pests, diseases or harsh weather.
Azaleas in an area with too much sun or shade won't thrive. This plant prefers a moderate mix of both. Excessive sun can cause infestations or scorch the plant, while an overabundance of shade will yield foliage but not flowers. See which spots in your yard have the right conditions, then move the plants so they will bloom.
Azaleas require a delicate balance of watering because they can't be allowed to dry out and do not like wet feet, either. Mulching can help with water retention and protect the roots from the heat. The mulch layer shouldn’t be any deeper than 2 to 3 inches. Keep your azaleas blooming all summer by watering them about an inch of water a week for consistent moisture.
If you fertilize your azaleas with high levels of nitrogen, it will interfere with blooming and spur foliage growth. Deer might have eaten the buds off your azaleas. Azaleas aren’t deer-resistant, so consider deer fencing around your flowering shrub.
Azaleas are vulnerable to insects such as aphids, borers, lace bugs, leafhoppers, mealybugs, mites, nematodes, scale, thrips and whiteflies that might weaken the leaves of the plant and inhibit its ability to flower. Address these pests with a horticultural oil such as neem oil.
Last year’s weather can affect this year’s blooms. Consider the following factors to determine if the weather is responsible for your azaleas not blooming:
- A period of drought during the prior year could have destroyed your azalea flower buds, resulting in no flowers — or fewer of them — for the current year.
- A frigid winter could have killed azalea flower buds. A lack of cold weather can sometimes result in plants not blooming since some azaleas have a chilling requirement.
- Unseasonably warm periods in the fall or spring can trick azaleas into blooming prematurely — called “bud blast” — and those buds won't open in the upcoming flowering season.
Azaleas prefer acidic soil, so they likely won't bloom if they are planted in non-acidic soil. Test your soil to see if you need to adjust the pH level.
Related content
