I'm working on regrading my yard and creating a terrace to handle some drainage problems. I live in a bustling city where every bit of green is precious, so keeping my beloved crepe myrtle is super important to me. It's located about 15 feet from my house and roughly 1.5 feet inside the property line.
Here's the plan: I'll create a terrace at ground level, but the crepe myrtle will be in its own elevated planter box—3 feet above the terrace, supported by a retaining wall, with a cedar bench surrounding it for aesthetics. My landscaper suggested a square planter with a 20-inch clearance around the trunk, the retaining wall at 3 feet tall, and the cedar bench on top.
However, I have some worries:
- How can I protect the tree's root system while I dig and install the wall?
- Is a 20-inch clearance sufficient for the roots to thrive? The space on the sides is a bit tight (you can see the area that has been dug out already).
- What tips do you have for ensuring this tree remains healthy in the long run, especially with a raised planter?
I'd love to hear from anyone who's done similar work or has advice on how to integrate mature trees into hardscapes safely. Can this be achieved without harming my tree?
2 Answers
Hey! The age and height of your crepe myrtle are significant factors here. If it’s around 9 or 10 years old, that’s a good sign, but be careful with the roots during the excavation process. When you create that planter box around it, make sure to do it in early fall. That way, when the tree goes dormant in winter, it can focus on adapting rather than healing from stress. Also, keep the soil moist before and during the transplant process, but avoid fertilizing this season as it can zap the tree's energy. 20 inches should work, but if you can swing it, give it 30-36 inches around for optimal root health. Once you're done, you might want to provide some shade with a cloth to help it adjust and protect it from the sun.
Just to add on to what PlanterPioneer77 said, it sounds like your idea of a planter box in the same spot is definitely a solid plan. Keeping it in place should minimize stress, even if its roots are a bit exposed. Just be mindful of keeping those roots protected as you build the planter. Post-installation, try to maintain moisture around the tree for a while—it'll really help. About frost protection, zone 7A shouldn't be too harsh, but you can use mulch around the base for insulation. Elevating the planter should naturally help keep it a bit warmer, too.