After crape myrtles bloom in the summer, they form lovely seed heads that last through the fall. The pods can be left for overwintering birds, or you can collect the seeds to use for growing in the spring.
As with many other landscape plants, crape myrtles are often hybrids, which means that the seeds might not produce a plant exactly like its parent. If you want the new plant to be exactly like the parent, you should propagate by cuttings rather than seeds.
But if you have a non-hybrid variety, or if you don’t have a specific variety in mind, it’s easy to propagate crape myrtles from seed. Here’s what you need to know to get started.
How to Collect Crape Myrtle Seeds
When the blossoms fade, crape myrtles form seed heads, clusters of pods that start out as greenish berries, then darken and dry out as the weather cools. Eventually, they pop open and the seeds fall to the ground, where sometimes they sprout on their own.
If the seed heads are opening, you can collect the seeds straight from the tree. Gently shake the pods over your hand or into a paper bag, and the seeds will fall right out. If the seed pods haven’t opened yet, you can cut the entire cluster, take it home and put it in a vase of water. It will open and drop the seeds within a few days, so you may want to sit the vase on a tray to catch them.
Gather the seeds and keep them dry and cool until you’re ready to plant. The seed coating is very papery, so be careful with them. Broken seeds might sprout, but intact ones will do better.
How to Plant the Seeds
Crape myrtle seeds will germinate most any time, but they will do best in early spring when the days are lengthening. Gently press them into the surface of a light, moist potting medium. Cover with a layer of milled sphagnum moss, and mist until damp. Cover the pot with plastic, and put in a warm, bright place (75° to 85° F).
The seeds should sprout in a few weeks. Once they sprout, you can remove the plastic and keep the seedlings moist and in bright light as they grow. Wait until they have two sets of true leaves before transplanting to individual pots. Keep the pots indoors until late spring, then move them to a shady spot outdoors for a couple of weeks to acclimate before planting. Bring them indoors if nighttime temperatures drop below 50° F.
Once the plants are acclimated, and warm weather is here to stay, you can plant them in their permanent homes. The seedlings will grow rapidly during the summer. Keep them well watered, and feed every few weeks with a balanced organic fertilizer.