Over a month ago, we had a hard freeze here on the Central Coast. Some folks recorded temperatures in our normally mild area down around 23°. This almost record dip followed weeks of warm weather with highs in the mid 70’s and some plants were still sporting tender new growth. It also occurred before the holidays and folks busy with their holiday preparation just weren’t ready for it. Many sub-tropical plants were severely frost damaged and some just won’t be coming back. Since then we have been getting many questions at the nursery about just what one should do with these damaged plants. I’ll address the most common here:
Should I cut it back?
In most cases, the answer is no. I realize it’s difficult to look at that ugly brown mass that used to be a geranium, but you must resist the urge to trim off those dry, burnt leaves. At least for now. Those dry leaves will help protect the base of the plant should we get another frost and the chances are likely that will happen. Our average last frost date isn’t until March so we still have a bit more winter to deal with. The dry leaves hold in air and serve as a bit of insulation for the plant so it’s best to wait until the end of February to trim those leaves back. The exception to this, however, would be in the case of things with succulent leaves. If the damaged area is mushy, it’s best to trim it out because mushy leaves can lead to fungal growth and rotting.
Do I water it?
That depends. It depends on the amount of damage, the water needs of your plant and the water retention abilities of your soil. If only the top of your citrus tree was burnt and it’s planted in the sandy Nipomo soil, yes, you will continue to water. Don’t overdo anything; just don’t let the root ball completely dry out. If your bougainvillea is planted in San Luis Obispo’s heavy clay soil and doesn’t have a green leaf on it, you probably want to wait. The clay soil will hold more water and since there are no leaves on the vine, it isn’t using any.
Should I feed it?
The answer is no. With our temperatures back in the 70’s feeding it now will encourage the plant to push out new growth. If we get another cold snap, it will freeze and you may have to wait even longer for it to recover. Wait until the end of February to feed with a slow release fertilizer following package directions and the middle of March to use a liquid fertilizer. At this point (unless we get a rare, late frost) it will be safe for your plants to put out new growth.
Is it dead?
Maybe. If your plant is completely brown, it might be dead. Some plants will send up new growth from the roots. Some woody perennials will leaf out again come spring. The best thing to do is to wait and see. I have seen plants that appear dead come back. Often, the recovery is slow and sometimes not much happens until about April. Come spring if all the branches are dried and brittle, you can try cutting the plant back to see if there are any live branches. You can also scrape off a bit of the brown bark near the base of the plant to see if there is any hint of green underneath. Green is a sign there is still life left.
Should I replant the same plant?
Maybe not. Frost occurrences like this are good learning experiences. Perhaps you don’t have the right plant in the right place. How frost impacts plants can vary greatly from city to city on the Central Coast and even from yard to yard. Since frost moves down, spots at the base of hills can get hit harder by frost. Now is a good time to note where you saw the most frost in your yard. Areas that remained fairly frost free might be a better place for that lemon tree than those that retained ice crystals until noon. Take a little time to research the frost hardiness of the plant that died. Was it really suitable for our area? Frost hardiness of plants within the same family can vary greatly. Some do better than others. Your goal should be to find a plant that looks attractive and can thrive in your space, not one you have to baby.