Salvias should be pruned in late fall and again in spring
QI have lots of plants that probably need pruning back in the winter but I’m not sure how much to prune back or when to do it. Plus, it seems to me that they have better protection against frosts and freezes if they haven’t been pruned back. Or is this an “old wives’ tale?”
I would appreciate any advice for Mexican and other salvias, of which I have many, and for calceolaria and calendrinia. I live in the San Francisco mid-peninsula foothills and most of the plants are on a deck that has significant wind exposure in winter.
I usually move them close together in the winter to help protect from the wind. On colder nights, I cover them with old sheets, but haven’t been pleased with the results, mildew and such.
— BARBARA Kaiser,
Menlo Park
AThe general rule of thumb when it comes to pruning is to prune your hardier plants in the early winter and leave the more frost-tender to the early spring. Pruning tends to spur new growth, but you also can safely prune winter dormant plants.
Each plant type, of course, has its own pruning schedule so it’s always best to research the specific plant for tips on timing and how to accomplish it. Some salvias like to be cut back severely while others need only a trim.
Salvias can be pruned twice a year — once in the late fall or early winter and once in the early spring. It’s also a good idea to cut off spent blooms and trim the plant after each flowering to prevent it from getting too leggy and woody.
Mexican salvia, also called Mexican sage, can withstand a heavy pruning in the late fall or early winter, and a sort of cleanup, light pruning in the early spring.
As for the calceolaria ( lady’s slipper) and calendrinia (rock purslane), neither plant requires pruning, although you should snip or pluck off spent blooms (deadhead) to encourage new flowers.
We are in the coldest days of the year, so it’s important to protect your plants, especially frost-tender ones. Grouping pots together in a sunny, protected area is a good idea, but you also can string old-fashioned outdoor Christmas lights around them to provide some extra warmth on the coldest nights.
Using sheets to cover them might seem like a good idea, but sheets can be problematic. Sheets take on and hold moisture, so they can cause freeze damage if they are touching plants. Instead, use frost cloth or row cover and try to avoid having the material touch the plants.
Building temporary structures over the plants will allow you to safely drape the plants with whatever cover you choose. To avoid mold and mildew, always remove the cover during the day, allowing the sun to warm the plants and the air to move freely around them.
If you know an overnight frost is expected, water all of your plants well, except for your succulents. They should remain dry.
Using heavy- duty frost cloth also will protect your plants from high winds, but you’ll need to anchor the cloth securely or you could be giving your neighbors a pricey gift.