Despite being a "clumping bamboo," Gracilis will spread and fill in over time.How quickly it will spread depends on your location.
- You're in Florida, so you can expect the clumps to at least double over a six month period provided they receive sufficient water.
- Of course, these plants will be more aggressive in spring summer and fall and will usually hit their peak in your area around July
- (Click here to read a post from a blogger in Jupiter, Florida talking about their bamboo gracilis.)
Yes, you can force the shape by putting in a concrete retaining wall.
- It might be less expensive to put in a a bamboo containment wall made out HDPE.
- Check this site for more info and good luck!
For more information:
Read "I'm interested in planting bamboo in my yard. How can I keep it from spreading?" a Q&A answered by Richard Heller.