“Frost Bite” by Bob Hill

This year’s Polar Fleece Winter could be damaging to plants that are borderline hardy in the Louisville area, but the important thing to remember is that it’s way too soon to tell. The good news is that our plants are much more susceptible to damage in the Spring or Fall due to strong temperature fluctuation. A sudden freeze in the Fall before the plants have had time to harden off can cause damage, as will a hard frost in the Spring that follows a warm spell when the delicate plant tissues and buds are fooled into thinking winter is over. In that case plants such as ornamental cherry or apple trees won’t bloom then, but they are not dead.

Plants have remarkable survival skills which is the reason they have been around for millions of years; humans can’t say the same! Bark can insulate trees from winter damage. Some plants have sugars and amino acids that can act as an anti-freeze; that ability kicks in when the days begin to shorten in the Fall. Other plants have the ability for their cells to super freeze, thus remaining liquid even as the temperature drops below 32 degrees. The very toughest of the trees found near Nome, Alaska have the ability to remove water from all their cells, hiding it between the cell walls where even sub-zero temperatures do no damage.

Meanwhile, all we can do is turn up the thermostat, initiate some warm thoughts about the Kentucky Derby and wait until Spring to assess the damage. The important thing? Don’t rush judgment day. Even if your valuable plant is obviously burned or damaged at its tips it can be salvaged…coming back to life near ground level, or certainly below the ground where the roots have been protected.

Keep your pruners handy, but hold off on the graveyard shovel until late April or May. Trim back the dead tips to where the new growth appears. Once the danger of a late Spring frost is past, water well and add a little general purpose fertilizer to the soil. If you’re not certain what’s dead, use the “Old Fingernail Test” and peel back the bark with your thumb nail. If it’s green below there, you’re in business.

Also, use this winter as a warning sign. Mulch your plants a little better next fall. Move the truly susceptible plants to a more protected area. And don’t be afraid to use those fun and funky borderline-hardy plants in the future – with protection. Our recent winters have generally been warmer and you’re not a real gardener unless you push the horticultural envelope a little bit, even unto death.