Crepe Myrtle Not Blooming: Shade Plus Pruning Mistakes
A crepe myrtle not blooming usually needs more sun, lighter pruning or less nitrogen. Clemson Cooperative Extension notes that crape myrtles in partial or full shade have reduced flowering. Flowers form on new growth, so heavy cuts plus heavy feeding can work against blooms.
The short answer
Check sun first. Clemson Cooperative Extension notes that crape myrtles in partial or full shade have reduced flowering plus more disease. Heavy nitrogen applications cause the plants to flower less. Flowers appear on new growth, so prune lightly in late winter or early spring if needed. Topping is not required for flowering.
How much sun does crepe myrtle need?
Clemson Cooperative Extension notes that the ideal planting site has well drained soil, full sun exposure plus good air circulation. Plants in partial or full shade flower less.
Shade also increases disease susceptibility, the same source notes. UF IFAS Gardening Solutions adds that crapemyrtle is well adapted to both heat plus drought.
NC State Extension notes that crape myrtle requires full sun plus moist, well drained soil. It will tolerate occasionally wet or dry soil once established.
How does pruning affect flowers?
Clemson Cooperative Extension notes that flowers on crape myrtle are produced on new growth. It will bloom more profusely if lightly pruned, but it produces plenty of flowers without any pruning.
Chopping off the tops of crape myrtles, known as topping, is very common, the same source notes. Many believe topping is required to promote flowering, which is a misconception.
NC State Extension advises that severe pruning or topping should not be needed to control size. If thinning is needed, do it in late winter or spring before the new growth on which blossoms appear begins.
| Cause | What you see | Source note |
|---|---|---|
| Shade | Few flowers plus more disease | Needs full sun |
| Topping | Severe cuts | Not needed for flowers |
| Heavy nitrogen | Lush leaves | Fewer flowers |
| Late pruning | Lost new growth | Prune in late winter |
Source: Clemson Cooperative Extension plus NC State Extension.
Can fertilizer reduce blooms?
Clemson Cooperative Extension notes that heavy nitrogen applications cause crape myrtles to flower less. They also push shoot plus leaf growth that may be subject to winter injury.
Shoots pushed by heavy feeding grow leaves rather than flowers, the same source suggests. If the plant is lush but bare of blooms, hold back on nitrogen.
Clemson adds that bloom time differs by cultivar. Large flower clusters appear on the tips of new branches beginning in early summer plus continue into fall.
How to: step by step
- Count how many hours of direct sun the plant gets.
- Where possible, thin nearby shade.
- Avoid topping.
- Prune lightly in late winter or early spring if needed.
- Cut to a side branch or close to the trunk.
- Hold back on heavy nitrogen.
Troubleshooting
Lush leaves, no flowers in shade: low light. Thin the shade.
Few flowers after hard cuts: topping. Prune lightly.
Leafy growth after heavy feeding: excess nitrogen. Feed less.
For related reading see planning an outdoor cannabis garden layout, soil checks for cannabis plus mulch for cannabis. Kind Seed Co also stocks cannabis seeds.
Sources
- Crape myrtle, Clemson Cooperative Extension HGIC
- Crape myrtle pruning, Clemson Cooperative Extension HGIC
- Crapemyrtle, UF/IFAS Gardening Solutions
- Lagerstroemia indica (crape myrtle), NC State Extension Gardener Plant Toolbox
FAQ
When do crepe myrtles bloom?
NC State Extension notes that common crape myrtle blooms from July to September with numerous showy flowers. Clemson Cooperative Extension adds that clusters appear on new branch tips beginning in early summer plus continue into fall. Bloom time varies depending on the cultivar, according to Clemson.
Should spent flowers be removed?
On smaller plants, yes. Clemson Cooperative Extension advises encouraging a second bloom in summer by pruning flowers immediately after they fade. The first flowers can be cut to promote a second bloom three to four weeks later. On tall mature plants, let seed heads drop naturally.
Do young crepe myrtles bloom?
Clemson Cooperative Extension notes that crape myrtles come in dwarf plus semi dwarf shrub sizes as well as small, medium plus large tree selections. Flowers form on new growth regardless of size. Choose a size that fits the space so that topping is never needed.
Why are crepe myrtle leaves spotted?
NC State Extension lists leaf spots plus powdery mildew as potential diseases. Clemson Cooperative Extension notes that plants in shade have increased disease susceptibility. UF IFAS Gardening Solutions suggests choosing a disease resistant cultivar, such as the powdery mildew resistant white cultivar Acoma.
Does topping help crepe myrtles flower?
No. Clemson Cooperative Extension calls the idea that a tree will flower better if severely pruned a common misconception. Topping has been nicknamed crape murder because of its effect on the plant. Allow tree types in a good site to develop their natural form.
