PLANTING FROM SEED: Crape Myrtle (Lagerstroemia Indica)

I planted the crape at the same time as the Redwoods, had about as much success as with the redwoods too. They needed to be soaked for twenty-four hours in water then sown. All that is required is water, warmth and light. They seem to be very sensitive to colder weather in the early stages, several didn't make it when I attempted to acclimatize from inside to outside conditions. Summer is coming but right now the weather still can dip in the 40' and 50's during the night. After about two weeks for germination they started growing slowly, those that were getting all day full sunlight seemed to grow slower than those getting partial sun for part of the day. Growth still seems slow after five weeks. Initially the growth was green but has turned to red and green now. The picture are of the two most grown plants. I used potting soil and vermiculite. About a 50/50 mixture.
Once again I am not an expert yet on Bonsai, I am still learning. If anyone has any helpful ideas or suggestions please feel free to comment.