What's wrong with my cape rush?
I bought 6 cape rush (Chondropetalum tectorum) last year from the garden center and planted them all in my front yard facing south. Four of them have nearly doubled in size while 2 of them remain puny. What's wrong? They all are watered on the same sprinkler system and I haven't fertilized. Any ideas why they might not be thriving like the others? Any suggestions on what I should do to them?