Stems Of Heather Plants Growing In Compost Have Turned Black - Proper Soil For Growing Heather

Question From: S. McAllister - Toquerville, Utah, United States
Q: I made three pots of Heather with ericaceous compost and within a few months in two of the pots the plant stems went black. They still have their flowers but don’t look well at all? Shall I just compost them or can they be rescued? The compost on those pots didn’t get compressed enough and reduced down after watering exposing some of the roots and it took a few days to buy more compost to put on top to cover them up more. Maybe roots got chilled?
(Click Images To View Larger Versions)

A: Planting in pure compost is a mistake. Heathers prefer somewhat lean soil that is fast draining or the will develop stem rot, which is what I think your plants are suffering,turning the stems of your plants black. I would compost them and start over using fresh potting soil. A good recipe for potting soil of heaths and heathers is as follows: To make a simple potting mix for ericaceous plants, begin with a base of half peat moss. Mix in 20 percent perlite, 10 percent compost, 10 percent garden soil and 10 percent sand. Best And Happy Yardening, Nancy