Spring is here, and your crepe myrtle is starting to leaf. You've been waiting a while to enjoy the attractive blooms the tree offers. But when do crepe myrtles bloom? We've checked with arborists for the official details.
Crepe myrtles do best in a warm climate. This means that you can expect blooms in southern, hotter areas in late May. Cooler zones offer blooms progressively later. In zone 6, you may not have flowers until early August.
Keep reading, and we'll cover specifics on when your tree blooms by zone. Then we'll offer some guidance on what to do if your plant isn't flowering. Further, this article provides help for those poor people who have tried for years to get their tree to flower in vain. Finally, we'll cover the importance of pruning a crepe myrtle and how to prune correctly.
What Month Does Crepe Myrtle Bloom?
Crepe myrtles start to leaf and bud in the spring. The flowers then bloom in summer. Depending on the specific cultivar of crepe myrtle and the planting zone, there is some variety.
Crepe myrtle thrives in a warm climate and with lots of light. As a result, zones further north take longer to bloom. In zone 6, the coldest zone that crepe myrtle can usually survive, your tree may not bloom until late July or early August.
Conversely, in zone 9, buds may appear by late March. Blooms then follow around the end of May or early June.
Expect leaves about a month after the last frost as a rule of thumb. Furthermore, allow about two months after this for flowers to develop.
For example, in zone 8, the latest frost date is March 28th. As a result, crepe myrtle trees should have leaves and buds by roughly the end of April. Approximate flowering time begins two months later, at the end of June.
Similarly, in zone 7, the last expected frost is April 3. Crepe myrtles begin leafing, then, in early May. In addition, blooms can occur by early July.
In zone 10, where frost is uncommon, crepe myrtle can potentially bloom by mid-May. Blooms last a long time, up to 100 days. Some varieties are bred to enhance early, long-lasting flowers. Good pruning and dead-heading spent flowers can extend the season.
No matter what zone you're located in, keep in mind that micro-climates and other weather anomalies may affect these outcomes. For this reason, you may want to use these guidelines for your specific region. For example, by knowing the specific date of your last frost, you can better predict when your tree will flower.
Why Is My Crepe Myrtle Not Blooming?
Crepe myrtle trees are valued for their beautiful blooms. So it's understandable to be concerned if you feel your tree is underperforming.
If your crepe myrtle is not blooming well, it may be due to one of the following problems:
Pruning too late or too aggressively
Flowers develop on current, new growth. If you've cut the tree back too late, you may have accidentally cut off this summer's flowers. Aggressive pruning may encourage the tree to focus its energy on branch growth rather than flowers, even when you prune at the correct time.
Not enough growth
Much like above, you need new growth for the flowers to have a place to develop. If your tree isn't growing, there won't be many flowers. Consider fertilizer in late winter/early spring to stimulate extra growth.
Too much fertilizer
Not enough fertilizer may lead to poor flowering; however, too much fertilizer can do the same. When excessive fertilizer and high amounts of nitrogen stimulate lots of leaf and tree growth, this can detract from flower development.
Wet soil
Poorly drained soil or very wet seasons can stress the tree. As a result, flowers may not be as bountiful. Crepe myrtles do best in well-drained soil. If this is a recurring problem, consider improving the drainage around the plant.
The health of the tree
Check over the tree for signs of distress. It may be affected by fungus growth, leaf spot, insect infestation, or other concerns.
My Crepe Myrtle Never Blooms, What To Do?
Many of these problems can affect a tree for a season or two but typically won't prevent blooming every single year. If your crepe myrtle tree has never managed to produce flowers, it's likely one of the following two things:
- Inadequate sunlight. Crepe myrtle thrives in full sunlight, around eight hours a day. Less than six hours of direct sunlight a day does not allow for proper bloom development.
- Bad pruning technique. There are many ways to ruin your flowers with improper pruning. Pruning at the wrong time can cut off the growth that would have supported your future blooms. Pruning too aggressively can prevent the tree from having adequate energy for flowering. However, not pruning may lead to stunted growth, which is also bad for blooms.
When Should Crepe Myrtles Be Pruned Back?
Timing is everything when it comes to pruning crepe myrtles. Prune your tree back in winter or sometime in early spring, before new growth has started.
Flowers develop on the new growth. If you prune too late and accidentally take off all the new wood, you're taking off the future flowers as well. For this reason, you want to prune within a few weeks of the last frost.
Most people advocate dormant pruning, done over the winter. This means that you prune before the tree breaks dormancy, which ensures that you won't be cutting off new growth, as there isn't any yet.
However, even dormant pruning occurs in most zones fairly wide time range. Crepe myrtle, overall, tends to stay dormant for a while. They aren't one of the earliest plants to leaf out in the spring.
In cooler zones, you can wait for the last frost and for temperatures to pick up. Because with crepe myrtle, you still have a few weeks while the tree is dormant.
In warmer, more southern areas, be sure not to wait too long. In certain regions, pruning in February or late January is relatively standard.
What Happens If You Don't Prune Crepe Myrtles?
First of all, it's important to note that there are a few different methods for pruning crepe myrtles. Most gardeners agree that crepe myrtle does not require much if any, pruning.
If your plant is in the right location and thriving, it can be acceptable to let it continue to thrive. Trim as necessary, removing unattractive growth to shape the plant. Similarly, remove stunted growth or poor-performing branches.
This is still, of course, a form of pruning. However, many people associate pruning with heavy, aggressive "topping" of the tree.
While this technique is common among professional landscapers or streets crews, it's rarely the best. These crews have many trees to trim and can't waste much time on each one. As a result, they may quickly "scalp" the top of the tree.
This removes a significant amount of the tree, forcing it into a small, maintained footprint. However, it's an aesthetic nightmare until the tree starts to regrow in the spring. Many critics refer to the process as "crepe murder."
There's little if any benefit to such aggressive pruning for the average home gardener. Continue to prune as needed for safety and keep the plant from growing out of control.
With no pruning, you may find that weak branches take away from the overall growth of the plant. Crowded branches may prevent proper airflow. And, of course, dead or dying branches pose risks as a potential hazard.
In Conclusion
Crepe myrtles are attractive flowering trees that begin blooming as early as late May. In cooler zones, flowering can be delayed as late as August. If your tree has poor bloom development, it commonly results from inadequate sunlight, poor tree growth, and insufficient fertilizer.
You can encourage and promote new growth by pruning in early spring. However, don't prune too late. Waiting to prune after new growth has started can lead to accidentally removing the areas where future flowers are already developing.
It's also prudent to avoid aggressive pruning. Most trees only require basic maintenance pruning to remove weak or dead growth. Only rare cases where your tree's growth is very stunted may require more excessive pruning. If this is the case, it may be more beneficial to improve the plant's location so it can thrive in a well-drained area with full sunlight.
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