Crape History 101
Although they are native to China, crape myrtles have become an icon for the South (and yes, that gets a capital “S”…because it is a specific place). The original crape myrtles, Lagerstroemia indica, were very prone to powdery mildew. Since 1956, breeders have crossed them with Lagerstroemia faurei (from Japan) and from there on out, crape myrtles became a whole new tree. The brilliant colors of the indicas combined with the disease resistance and beautiful exfoliating bark of the faureis, to create the crapes we see today. Breeding programs have developed crapes for every situation, from stately shade trees to practically a ground cover, and in colors from pure white through every shade of pink, reds and purples. Tack on a long blooming season and you can see why crapes are so popular. Hundreds of varieties now exist, but sadly many are not suitable for Houston’s unique environment.
How to select the right Crape Myrtle:
After you answer a few questions, it will be easy to select the right variety.
- What color do you want?
- What shape do you want?
- How tall do you want it to get?
- Do you have the right location?
Step 1: Color is a subjective thing and it’s always the first thing we think about. If you are starting with a blank slate, then you can pretty much pick any color you want and build off that. If you’re adding to your landscape, you might want to take into consideration the colors of the existing plants and what time of year they are in bloom. With so many colors to choose from, you’re sure to find one you will love.
STEP 2: Shape Yes, Crapes have natural shapes. Some are shaped like Olive Oyl, tall and skinny others are shaped more like Wimpy, with a fuller figure. Some look like a small weeping willow and others are the Y…in the YMCA dance….it’s a mixed group. The following are considered to be the 5 forms crapes come in.
- Upright or vase is taller than they are wide.
- Rounded or globose are as wide as they are tall.
- Spreading is wider than they are tall.
- Weeping is naturally small and should rarely be pruned.
- Columnar are very narrow and upright.
Step 3: Size Crapes are grouped into categories by size. Visualizing the mature size in the landscape will help you decide which category you want. Trying to force a particular variety to stay shorter is never advised…unless you are trying to create a bonsai. Repeated attempts to control the height of a crape, is a form of “Crape Murder”, which will be discussed later. If you want a crape in front of your home, it needs to be planted at least half the diameter of the mature canopy, away from the wall. For example; if the mature size is 20 feet wide, then you should plant it at least, 10 feet from the wall. This allows the crape to achieve its mature size and shape, with very little pruning and allows for good air flow around it. Planting a tree that wants to be 30 foot tall 3 feet from your foundation is a rooky mistake. We see it all the time and we just shake our heads.
- Miniature usually under 3’ tall and take on a “weeping” shape.
- Dwarf these are usually 3’ to 6’ and make great hedges.
- Intermediate between 6’ and 12’, use as a tall hedge, as a specimen or accent.
- Tree or Tall typically over 15’ tall, use as an accent or for some real shade.
Step 4: Site Imagine standing in the middle of the road, on the highest section of the 610/59 interchange…this situation would be considered full sun and a crape myrtle would love it. “Mostly” or “quite” sunny, will not cut it. Oh, they will survive in less than 8 hours of DIRECT SUN, but they won’t be happy, vigorous or full of leaves. In less than 8 hours of DIRECT SUN, they will get powdery mildew and aphids. On top of all that, we plant crapes because we like the flowers, full sun means full of flowers. Trust me on this; I have a crape that has never thrown more than a few flowers a year (threats apparently don’t work and at this point it knows my threats are empty).
Air circulation is the next consideration in choosing a planting site. Cross off all ideas of planting a crape against a fence, a wall or beside a tall hedge. They need excellent air flow and anything that hinders air flow will cause your crape problems. Poor air circulation leads to powdery mildew. This fungus is a climatic event, triggered when we have hot, humid days and cool nights in the spring and fall. Some varieties are more susceptible than other, so select varieties that have proven themselves in your area.
One other word of warning, if you have a pool… unless you find that cleaning your pool is the best way for you to relax; you really should avoid planting a crape near it. They drop flowers and leaves.
HELP!!!! My crape has a problem!
It looks like there is white powder on the leaves and flower buds.
Powdery mildew is a fungus triggered during specific climatic conditions (hot, humid days and cool nights) in the spring and fall. Act quickly using a fungicide (like Mancozeb) to prevent damage to the flower buds. Multiple sprayings may be needed, until the weather changes.
My leaves are sticky and my car/patio/dog is too.
Aphids, scale or mealy bugs are the culprit here. The sticky substance is called “honey dew”…face it, its bug poop. Control the insects and the problem will go away. Use Dominion, a systemic insecticide in late February through March. It is a mix-and-pour product, making application easy, quick and not messy. One application will prevent bugs for about 9 months. This is one of the situations where we suggest preventative chemical applications. Spray several times in the winter with All Seasons Oil Spray to kill over wintering insects that are just waiting for warmer weather and a hot date.
My leaves are turning black and my car/patio/dog is too.
If you wait too long to treat the bugs in the previous paragraph, the “honey dew” grows a fungus call Black Sooty Mold. Get rid of the bugs, and the problem goes away. If the situation is allowed to continue, it will be near impossible to get it off the leaves. When the leaves drop on the fall, it will go away, but be proactive in the spring and treat with Dominion in February or March.
The tips of my leaves are turning brown and crunchy.
Too much water is the problem here. Crapes are seriously drought tolerant. Cut back on the water.
Why won’t my crape bloom?
Not enough sun. Read the section above about site. Insects or Powdery Mildew damaged the buds to the point of flowering failure.
What do I do about the little sprouts popping out of the trunk?
Keep cutting them off, close to the trunk. If you catch them early, you can brush them off with your hand.
Can I make this multi trunk tree into a single trunk tree?
Yes and no. Yes if you start with a very young tree. Pick a 1 or 5 gallon size that has a single, straight trunk or one that has one really good trunk and a few puny ones you can remove. Keep the suckers pruned off and stake it to keep it straight. It is a lot of work, but the results can be stunning. If you already have a multi-trunk tree, learn to love it, or replace it. If you remove all the extra trunks, they will constantly try to sprout. If you try to poison them, it will kill the one you want to keep, because the roots have all grown together.
Why is my crape dying?
Do you use weed and feed that has Atrazine in it? Most weed and feeds have this chemical in them, read the label. It says right on the bag “do not use on the root zone of desirable trees”. Since the roots of your trees extend under the grass, up to 3 times the width of the canopy, chances are you are poisoning your trees…and frogs, toads, lizards, cat, dog, kids and yourself. Atrazine is monitored in our water…and is probably as bad as DDT.
When planting, follow our Tree Planting Guide https://rcwnurseries.com/data/stories_rcw/other/4_new-tree-planting-instructions.pdf,
Follow our Tree Care guide https://rcwnurseries.com/data/stories_rcw/other/44_First-Year-Tree-Care.pdf
Watch these videos on pruning crapes, help stop Crape Murder