Rejuvenating a Silver Flaming Pieris Bush

Credit: Courtesy Elsie Lapinsky

Q: I have 10 Flaming Silver Pieris bushes which took a turn for the worst in the winter of 2008. I believe the cold and wind was just too much for them and now they’re not nearly as dense as they used to be. Some of the branches died and I cut them off. Is there some way that I can help them to recover and become the full, beautiful bushes that they once were?

Your Pieris japonica ‘Flaming Silver’ does look a bit bare at the bottom. I wonder if it might have dried out during the heat of the summer, as well as having to cope with a cold winter. Cold usually damages the tips, while drought stress can cause a shrub to drop leaves. You also mentioned wind. If the plant is in a cold, windy spot, that will also cause the soil to dry out, even in winter.

I observed many plants after the winter of 2008-2009 and talked with customers at the garden centre where I work. There is no doubt that plants that were dry going into winter sustained much more cold damage. Gardeners don’t always water in the fall, but if there is no rain, the plants can be very dry. The winter cold acts as a dessicant and tissues dry out. I was lucky—I had watered well into the fall and then mulched all my plants in the fall as well (mainly because I couldn’t do it in spring!). I had hardly any damage, yet I saw the same plants in my neighbourhood that were very damaged by the frost.

Anything in the rhododendron family (as the Pieris is) is more susceptible to drought because of the fine roots in this family. So I would:
a) move your plants if the site is too exposed
b) mulch them and water them well, even in late fall if the weather is dry
c) use a good organic rhodo fertilizer in May
d) mulch the soil in March

Plants in this family also respond well to pruning as they produce new shoots on old, woody stems. So you could gently prune the tips after the plants bloom to encourage growth from below. I’ve even cut rhododendrons down almost to ground level to rejuvenate them. But this seems way too harsh for your little Pieris.

With any luck, by the time you get this answer, they will have recovered fully.