Frozen plants, how soon can we prune?
January and February are tricky months for us. One day it’s over 70 degrees and sunny, and then just 24 hours later, freezing with a chance for sleet!
Pruning, especially combined with warmer temperatures and bright light, encourages growth, and exposes those tender new stems and leaves, making them more vulnerable when polar blasts returns.
Note: don’t tidy up too fast since seeds on grasses and perennials feed birds. They provide cover for all kinds of beneficial creatures like butterflies. Dense dormant growth also shelters the living roots underneath. We do want to prune before new growth is on its way.
So, when do we do it?
Any time after freeze
Woody dormant plants like flame acanthus, turks cap and others that are complete sticks
Rosemary (just to shape: January and February) Cut leaves any time of the year.
Herbaceous salvias like ‘Black and Blue’ and ‘Indigo Spires’ that are sticks
Salvia greggiis (cut back several inches, depending on plant size)
Asters, native salvias like reglas, coneflowers, mums: cut to their rosettes
Copper canyon daisy, mistflowers and other natives that are dormant; prune to ground
Clumping grasses (shear to 3-6” above ground), Inland sea oats (cut to rosettes)
If bamboo muhly froze, cut this grass to the ground for new shoots
Individual microclimates and weather make a difference with the more tender plants. Some of us can prune plumbago and lantana in February. Others may want to wait until March.
March to Mid-March
Evergreen shrubs, unless they are spring bloomers like viburnum
Tecoma stans (Esperanza)
Barbados cherry (though possibly earlier)
Succulents like purple heart. Since succulent leaves are full of water, once they freeze, the cell walls burst when they thaw, meaning that lovely new growth will be fried in the almost inevitable late winter blast of polar cold.
Annuals like native Salvia coccinea will not return after super hard freezes. But the seeds they set may come back in warm weather, though perhaps not where you wanted them!
Flax lily, Dianella. Below 25 degrees and it’s gone.
AGAIN! Get to know your microclimates, even in your own yard.