Crepe myrtles are popular for their bright and colourful flowers. From screening and hedges to container plants and garden focal points, there is no lack of uses for this attractive ornamental plant.
The Basics of the Crepe Myrtle
Crepe myrtle or Lagerstroemia is a genus of about 50 flowering trees and shrub species native to Asia, northern Australia, and some parts of Oceania. Species of crepe myrtle are either deciduous or evergreen.
Species of Lagerstroemia range from shrubs which grow to no more than 3 feet (1 metre), to trees that grow to more than 30 feet (10 metres) tall. Some species can grow up to 100 feet (30 metres).
Crepe myrtle’s growth rate varies depending on how tall it ultimately grows. The larger varieties, those that rise higher than 25 feet (7 metres) will grow at a rate of about 3 to 5 feet (1 to 1.5 metres) per season prior to blooming. The smaller or dwarf species may grow to about 6 inches to a foot (15 to 30 cm) each growing season.
The Lagerstroemia got its common name from the crêpe-like texture of its flowers that bloom in white or different shades of reds and purples. There are no blue, yellow, or orange varieties of crepe myrtle yet, but its stamens and pistils are usually orange or yellow.
Crepe myrtles bloom at around late spring to early summer.
The colour of the leaves also varies from specie to specie. Some will have bright green leaves, others deeper green, and there are crepe myrtles with dark green-purple to bluish leaves.
Crepe myrtles are native to warmer climates, but there are varieties available that can thrive in colder regions.
Planting Your Crepe Myrtle
Certain varieties of crepe myrtle can be used as an individual garden addition, in containers, or in groups as hedges or privacy screens.
Choose a dwarf or medium variety for hedges and privacy screens. Dwarf and medium crepe myrtles are also ideal for planting around the house or by windowsills.
Larger varieties are more suitable as individual plants. Place them away from your house, poles, and lines to avoid hazards.
There are so many varieties of crepe myrtles to choose from, so make sure to get the type that is suitable for the purpose you intended.
As much as possible, plant crepe myrtle where the sun can reach it in the morning to dry out the dew on the plant. Crepe myrtles like to stay dry.
It is best to plant crepe myrtles in the early to late spring, but early summer planting could also work in certain conditions.
If you will plant them as individual plants, give the crepe myrtle about 8 to 10 feet (2.5 to 3 metres) of space in between. For crepe myrtle hedges, plant them 4 to 6 feet (1.2 to 2 metres) apart.
When planting from containers, water the crepe myrtles first before transplanting to help aid in the absorption of moisture when they are put in the ground.
Do not plant them too deep. The top part of the ball should be about an inch (2.5 cm) above the ground level.
Mulch the surrounding soil without covering the root ball to help preserve moisture.
How to Propagate Crepe Myrtle
Propagating from Cuttings
You can propagate crepe myrtle from cuttings.
Gather cuttings from first-year growth along the mature stems or trunk. More ideally, get the cuttings from the suckers which shoot out from the bottom of the tree. Get cuttings of about 4 to 6 inches (10 to 15 cm) each.
Cut each one just below a node (nodal cutting). Leave the top 2 or 3 leaves from the cutting and remove the rest.
Use a rooting medium such as wet sand or seed starter soil and stick the cuttings in it. Crepe myrtles root well and will root in about 4 to 8 weeks even without rooting hormones, depending on the condition.
Propagating from Seeds
Crepe myrtle is known for being a challenge to grow from seeds. But it does not mean that you cannot try.
You can collect crepe myrtle seeds from its pods in late autumn to mid-winter. You may not find a lot of excellent and unopened seed pods if you wait until late winter to collect seeds.
You can choose to start your seed either through the paper towel method or on seed starter soil.
For the paper towel method, moisten a paper towel and place seeds on the half part of it, keeping the seeds spaced out. Fold the paper towel over the crepe myrtle seeds and place inside a sealed bag.
If you choose to use a seed starter soil, you can use individual seed pots or a bigger container. Spread out the seeds over the soil and water it. Put a very thin layer of more soil just enough to cover the seeds, but not too much, and water again.
Wait a few weeks until you see sprouts.
Transplant the seedlings to bigger containers once they are about 4 inches (10 cm) tall.
Caring for Your Crepe Myrtle
Crepe myrtles love the sun, are hardy, and drought tolerant.
For the first year, water more frequently, about 2-3 times a week depending on the weather. Just make sure that the soil of your crepe myrtle does not stay too wet.
For mature crepe myrtles, water about once a week, allowing the soil to dry out in between watering.
Even if crepe myrtles are hardy, do not allow them to stay dry for too long, especially during the blooming season. You will notice that it will have fewer flowers if watering has been neglected for too long.
The best time to fertilise crepe myrtle is in late winter to early spring, just before they break dormancy. The latest time to fertilise is in mid-summer. Fertilising from late summer onwards may result in damage to the plant during winter.
Crepe myrtles are known to break dormancy later than other plants—about one to two weeks. So, do not be alarmed or puzzled if you see bare stems on your crepe myrtle while your other plants are starting to grow new leaves.
Prune crepe myrtles to shape to encourage bushier growth in late winter or early spring. However, do not prune too much, no matter if you see others do it.
Too much pruning of crepe myrtle, which someone coined as “crepe murder,” will ruin its form and encourage the growth of thinner and flimsier stems.
The proper pruning of crepe myrtle should be just to prune formally and remove dead stems, leaves and flowers.
Remove as much stem to maintain spaces in between the lower trunk and stems while maintaining the canopy. A good rule of thumb for pruning crepe myrtle is that birds should be able to fly through the trunks and lower stems.
Common Problems with Crepe Myrtle
Lots of insects like Japanese beetles love crepe myrtle, but the more concerning ones are the aphids.
Watch out for aphids in the early spring as the crepe myrtle starts getting new growth. These pests secrete a sugary substance that drops down to the lower part of the plant, and this substance encourages the growth of mould on the leaves.
Although the aphids or mould itself may not damage the crepe myrtle, the mould will block the leaves and prevent them from getting nutrients from the sun.
Address the aphid issue as soon as you catch it to avoid damage to your crepe myrtle. Aphids can be addressed by spraying plain water or pesticides.