Growing crepe myrtle trees

WA Scene | July 23, 2022 | 0 Comments

How to grow crepe myrtle trees

Crepe myrtles (Lagerstroemia spp) are a wonderful tree native to primarily to Asia. With approximately 50 species for crepe myrtles there is a colour to suite most tastes. The most popular in Australia is Lagerstroemia indica as it grows well in Perth and most other parts of Australia.

If you have ever wondered how to grow crepe myrtle in Perth then look no further. Crepe myrtle are a relatively easy tree to grow, and there are a few tricks to successfully growing crepe myrtle trees in Australia. Get these right and you will be laughing.

Crepe myrtles are frost tolerant but young plants may need some protection until they develop hardened wood and some height about them.

They are capable of withstanding our hot dry summers but will still appreciate some summer watering. Be sure to give extra water to new plants through their first summer to help them establish well. Crepe myrtles will also happily grow in the warm humid conditions of northern parts of Western Australia.

When to plant crepe myrtle trees in Australia

All crepe myrtles grow well in Australia. They especially like a hot and dry climate. You can plant crepe myrtle most months of the year, but it’s best to plant crepe myrtle trees during autumn. This will allow your plant time to establish roots before winter.

How much water do crepe myrtle trees need

In the warmer parts of Australia like Perth I recommend watering crepe myrtle deeply, one to two times a week, depending on weather conditions.

How long can crepe myrtle trees live

A crepe myrtle lifespan can exceed 50 years and it has been widely reported that some have reached over 100 years old.

How to prune crepe myrtle

Pruning a crepe myrtle is really simple. Wait until the flowers have finished and then cut it back at least 30 centimetres. It is a good idea to prune quite hard because in spring the branch will shoot out with new growth. But if you don’t want to prune, then just let the plant grow to its natural shape.

How far apart to plant crepe myrtle

There is no correct planting interval for crepe myrtle trees. Spacing is based on the mature size of the plants. When grown as shrubs, the crepe myrtle should be spaced about 6 feet apart however many gardeners suggest further apart than this depending on the planting location.

How fast do crepe myrtle grow

Crepe myrtle’s growth rate can vary by type and growing conditions. The larger varieties, those that rise higher than 7 metres will grow at a rate of about 1 to 1.5 metres per season prior to blooming. The smaller or dwarf species may grow to about 20 to 30 cm each growing season.

How to grow crepe myrtle at home

If you are wondering how to plant a crepe myrtle tree in the garden then look no further. Growing crepe myrtle trees in the backyard has become increasingly popular over recent years.

Choose a sunny spot with well drained soil. Enrich the soil with soil improver as required. If the soil is heavy or clay based, add some gypsum and fork in well to improve the drainage.
Dig the planting hole twice as wide and to the same depth as the root-ball of your crepe myrtle. Remove the shrub from the container, gently tease the roots.
Position crepe myrtle plant in hole and back-fill with soil, gently firming down. Water in well.
Mulch around the base with organic mulch like bark chips or pea straw, keep the mulch away from contacting the actual trunk of the tree.
Water deeply, once or twice a week, depending on weather conditions.

How to grow crepe myrtles trees in pots

Growing crepe myrtle trees in pots is a great idea if you want to grow a relatively small crepe myrtle tree. I love to grow crepe myrtle trees in pots because it gives you the flexibility to move them around the yard for maximum impact.

Choose a pot that is at least twice the size of the selected plant usually 60cm or bigger. Position in the garden in a location that receives full sun to half shade.
Dig the crepe myrtle planting hole twice as wide and to the same depth as the root-ball. Remove the shrub from the container, gently tease the roots.
Position the crepe myrtle in the hole and back-fill with soil, gently firming down the topsoil. Form a raised ring around the plant, creating a well so that water will go where it’s needed most at the base of the plant. Water in well.
Feed with a complete organic fertiliser.

How to propagate crepe myrtle trees from cuttings

Propagating crepe myrtle trees by cutting is a good option if you have a friend with a tree. The best time to propagate crepe myrtle is in early spring or with temperature of 20-26C and better before the plant start to grow after the dormant period over winter. Choose stems that not going to bloom, cut a stem around 20-30cm in length. Plant in a high quality potting mix with moist peat soil, I like to dip the end in some root hormone to help the root growth. If you have a greenhouse then I recommend to use green house or a makeshift version plastic box with holes it. It should take 3-4 weeks for you cutting to start to grow. Once it has established fro 3-4 months you can then transplant to the desired location or to a new pot.

How to transplant a crepe myrtle

Crepe myrtle transplanting is easy with three basic steps.

Digging a hole in an appropriate new site – Dig out a new planting hole large enough to fit all of the tree’s current roots, but a bit wider, to allow those roots to expand.
Digging out the root-ball – Dig around the outside of the roots, taking a root ball that is 0.5 – 1m in diameter depending on the size of the tree. This will ensure that the plant moves to its new location with sufficient roots to survive.
Transplanting a crepe myrtle in the new spot – With the the right number of people to help with the lift of the tree, lift the root ball onto a tarp. Then pull the tarp over to the new planting site and set the root ball in the hole. Top of the root ball is even with the soil surface. Flood the root area with water. Keep watering regularly during the first few growing seasons at the new location.

The best time to move a crepe myrtle is when the tree is dormant. That period runs from the time the tree loses its leaves to the start of spring.

How to fertilise crepe myrtle trees

Fertilise with a complete organic fertiliser. Look for one that’s fairly high in nitrogen and potassium and follow the directions on the bag.

When do crepe myrtle trees bloom

A common question a lot of first time planters will ask is when does a crepe myrtle tree flower? Crepe myrtle will produces clusters of ruffled flowers in summer and autumn that provide a long lasting display for months.

Crepe myrtle problems

Aphids are a common problem for crepe myrtle trees. Keep a close eye for them in the early spring as the crepe myrtle starts getting new growth. Aphids will 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.

It’s best to quickly treat Aphids by spraying them with a suitable pesticide from your local gardening supply store.