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You can fertilize a crepe myrtle in the summer, but it’s not always the best idea for every situation.
In fact, fertilizing a crepe myrtle in the summer can be beneficial if done correctly, but it can also cause more harm than good if you’re not careful.
The key is understanding your tree’s needs, the type of fertilizer you’re using, and the timing of your application.
In this post, we’ll dive deep into whether you can fertilize a crepe myrtle in the summer, when it makes sense, and when you should hold off.
We’ll also cover the best fertilizers to use, how to apply them, and common mistakes to avoid so your crepe myrtle thrives all season long.
Let’s dig in and help you make the right call for your tree.
Why You Can Fertilize a Crepe Myrtle in the Summer
The short answer is yes, you can fertilize a crepe myrtle in the summer, but it depends on your goals and the tree’s current condition.
Crepe myrtles are vigorous growers that respond well to nutrients, especially during their active growing season.
Summer is when your crepe myrtle is putting out new growth, producing buds, and blooming, so it’s actively using energy and nutrients from the soil.
If you’re wondering if you can fertilize a crepe myrtle in the summer to boost blooms, the answer is yes, but only with the right approach.
Let’s break down the factors that make summer fertilization a good move or a risky one.
1. The Tree’s Growth Stage Matters
If your crepe myrtle is young and still establishing its root system, you can fertilize a crepe myrtle in the summer to encourage strong, healthy growth.
Young trees benefit from a balanced fertilizer that provides nitrogen, phosphorus, and potassium to support root and shoot development.
However, if your crepe myrtle is mature and established, it may not need summer feeding at all.
Mature trees often get enough nutrients from the soil, especially if you’ve been amending your soil with compost or mulch.
So, while you can fertilize a crepe myrtle in the summer, it’s more critical for younger trees that need a growth boost.
2. Timing Within the Summer Is Key
When you fertilize a crepe myrtle in the summer, early summer is safer than late summer.
Fertilizing in early June or July gives your tree time to use those nutrients for active growth and blooming.
But if you fertilize a crepe myrtle in late August or September, you risk pushing new growth that won’t harden off before winter.
That tender new growth can be damaged by frost, weakening the tree and reducing its vigor next year.
So, if you’re going to fertilize a crepe myrtle in the summer, do it early in the season, not at the tail end.
3. Fertilizer Type Makes a Huge Difference
You can fertilize a crepe myrtle in the summer with a slow-release fertilizer, but you should avoid high-nitrogen fast-release formulas.
Slow-release fertilizers provide a steady supply of nutrients over several weeks, reducing the risk of burning roots or forcing excessive leafy growth.
High-nitrogen fertilizers can cause your crepe myrtle to put all its energy into leaves instead of flowers.
That means fewer blooms and a lanky, less attractive tree.
Look for a fertilizer with a lower middle number (phosphorus) to encourage flowering, like a 8-8-8 or 10-10-10 balanced mix.
Alternatively, use a fertilizer specifically formulated for flowering trees and shrubs.
When You Should Not Fertilize a Crepe Myrtle in the Summer
While you can fertilize a crepe myrtle in the summer, there are times when it’s better to skip it altogether.
Understanding these situations will save you from making a costly mistake.
1. During Extreme Heat or Drought
If you’re in the middle of a heatwave or your area is experiencing drought conditions, do not fertilize a crepe myrtle in the summer.
Fertilizer encourages new growth, which requires water to sustain.
If the tree is already stressed from lack of moisture, the added nutrient load can cause leaf burn or root damage.
Wait until temperatures cool down and the soil has adequate moisture before applying any fertilizer.
2. If the Tree Is Already Blooming Well
If your crepe myrtle is already producing abundant blooms, you don’t need to fertilize a crepe myrtle in the summer.
Adding fertilizer at this point can push out new leafy growth that competes with flower production.
In fact, over-fertilizing is one of the leading causes of poor blooming in crepe myrtles.
So, if your tree looks healthy and is flowering nicely, leave it alone.
3. If You’ve Already Fertilized in Spring
If you applied a slow-release fertilizer in early spring, you should not fertilize a crepe myrtle in the summer.
That spring application is usually enough to carry the tree through the entire growing season.
Adding more nutrients in summer can lead to salt buildup in the soil, which can harm beneficial microorganisms and roots.
Check your soil’s nutrient levels or simply observe your tree’s growth before deciding to add more fertilizer.
How to Fertilize a Crepe Myrtle in the Summer Safely
If you’ve decided that you can fertilize a crepe myrtle in the summer and it’s the right move for your tree, here’s how to do it safely.
Following these steps will help you avoid common pitfalls and ensure your tree gets the nutrients it needs.
1. Water the Tree First
Before fertilizing, water the soil around your crepe myrtle thoroughly.
This ensures the roots are hydrated and reduces the risk of fertilizer burn.
Moist soil also helps the fertilizer dissolve and reach the root zone more effectively.
Wait a day after watering, then apply the fertilizer.
2. Apply Fertilizer at the Right Depth and Distance
Spread the fertilizer evenly around the drip line, which is the area directly below the outer edge of the canopy.
Avoid piling fertilizer against the trunk, as this can cause stem rot or burn.
Gently work the fertilizer into the top inch of soil with a rake or hand cultivator.
Then water again lightly to help it settle into the soil.
3. Use the Correct Amount
The amount of fertilizer you need depends on the size of your tree and the product’s instructions.
As a general rule, use about one pound of fertilizer per inch of trunk diameter.
But always follow the label on your specific fertilizer product.
Over-fertilizing is a common mistake, so err on the side of caution and use less rather than more.
You can always add more later if needed, but you can’t easily undo over-fertilization.
Signs Your Crepe Myrtle Needs Summer Fertilization
Beyond just asking “can you fertilize a crepe myrtle in the summer,” it’s smart to look for signs that your tree actually needs it.
Not every crepe myrtle will benefit from summer feeding.
Here are a few clues that your tree might be nutrient deficient.
1. Pale or Yellowing Leaves
If your crepe myrtle’s leaves are looking pale green or yellow, it could be a nitrogen deficiency.
In that case, you can fertilize a crepe myrtle in the summer to correct the issue.
Apply a balanced fertilizer and monitor the leaves over the next few weeks.
They should green up if the problem was nutrient-related.
2. Stunted Growth or Few Blooms
If your crepe myrtle isn’t growing as much as it should, or if it’s producing very few flowers, it might need a nutrient boost.
You can fertilize a crepe myrtle in the summer to encourage more vigorous growth and better flowering.
Just make sure the tree gets enough water and sunlight as well.
3. Poor Soil Quality
If your soil is sandy, rocky, or heavily compacted, it may not hold nutrients well.
In these cases, you can fertilize a crepe myrtle in the summer to compensate for poor soil.
Consider adding organic matter like compost to improve soil structure over time.
So, Can You Fertilize a Crepe Myrtle in the Summer?
Yes, you can fertilize a crepe myrtle in the summer if you follow the right guidelines.
Early summer is the safest time, and using a slow-release, balanced fertilizer is your best bet.
But if your tree is mature, blooming well, or stressed by heat and drought, it’s better to skip summer feeding.
Always water before and after applying fertilizer, spread it around the drip line, and avoid overdoing the amount.
Watch your tree for signs of nutrient deficiency, and adjust your approach based on its specific needs.
With the right care, your crepe myrtle can thrive through the summer and put on a spectacular show of blooms.
So, monitor your tree’s health and make an informed decision about whether you can fertilize a crepe myrtle in the summer this year.
Your crepe myrtle will thank you with lush growth and vibrant flowers.