Things You'll Need
Small jar or envelope
Potting soil or soil, perlite and peat moss.
40 watt fluorescent shop light
Crape myrtle trees, Lagerstroemia indica, originated in Asia. People grow the crape myrtle for its blooms, which vary in color from white to dark purple. The crape myrtle trees are hardy in U.S. zones 7 through 9, but some varieties can grow in slightly colder regions like Boston. No need to go to the nursery and buy a crape myrtle when you can germinate the crape myrtle seeds and grow your own tree.
Collect the seed pods. The seeds begin as pea-sized berries formed after the crape myrtle tree flowers. The berries turn into seedpods. Pick the seedpods in the fall after they turn brown, but don't wait too long or the pods burst open, spilling the seeds onto the ground. Inside each pod there are four to six seeds.
Remove the seeds from the pods and store them in a small jar or envelope until the spring. One month before you want to sow the seeds, place the seeds in the refrigerator, or another area where the temperature is cool but not freezing. Leave the seeds in cool storage for 30 to 45 days. Plant the seeds indoors two months before you want to plant them outdoors.
Fill a 4-inch pot with moist potting soil. You can buy potting soil in the garden stores or mix your own. To mix your own potting soil, combine equal amounts of soil, perlite and peat moss.
Press one seed into the center of each pot, just so the seed is in contact with the soil. Cover the seed with a thin layer of potting soil and then add a thin layer of sphagnum moss over the top.
Cover the pot with a plastic bag and close the bag. The air will retain humidity to enable the seed to germinate.
Place the covered pot in a warm, sunny location that remains at a temperature of around 75 degrees Fahrenheit during the day. The soil should remain moist, but not soggy. It takes up to three weeks for the crape myrtle seeds to germinate.
Remove the plastic cover and place the pots under a 40 watt fluorescent shop light. Position the light at least 8 inches above the plant.
Harden off the crape myrtle by taking the pots outdoors. Place them in a protected area out of direct sunlight and wind. Do this over the course of 10 to 14 days, increasing the outdoor time by an hour each day. Plant the crape myrtle tree in a sunny area.