In the hopes that our Winter Wonderland is behind us and the comfortable warm temperatures will be around for a while, we are making plans for the start of the growing season of 2018. But no matter which end of the Valley you are in, the state of affairs in the garden can look pretty grim following a deep chill/freeze like we experienced at the start of this year.
While sometimes it is very evident that damage has occurred and often with the more tropical plants, it may take several weeks for damage to actually show up. More than once we have looked over our trees following a cold event and said “Wow, they did great!” to only gnash our teeth 2 weeks later when the true damage begins to show itself.
Generally the first thing most of us notice are leaves. There can simply some spotting from the cold to wilting to dead leaves to total leaf drop. And though it is sad to look at tree surrounded by a sea of dead leaves, that is actually a better sign then a tree with dead leaves that are persistently hanging on the stems. If the leaves are dead and hanging on, that means there is some stem damage.
With all the warm weather we have had this year, many of us had mangos that came out early with blooms. Depending on the point in the flowering cycle your tree (s) was at, you may lose those fruit panicles. Watch them for signs of breakdown. A pre-emptive fungicide spraying is a good idea to reduce the possibility of fungal infections if your tree reblooms. And remove any flowering panicles that did not set any fruit.
Twig, limb and even trunk damage may have occurred. This damage can range from discoloration to bark splitting and sap exudation and even death of a branch or the tree itself.
For those plants or trees with no visible twig or limb damage—DO NOT PRUNE until we are on the other side of another cold event. You cannot tell what is dead at this time and you may prune live wood. And then there may be another freeze and even the dead leaves will provide some insulation to heat loss.
If you prune immediately you may not even remove all the dead wood and you will simply have to prune again later. It sometimes can take as long as 6 months before all the damage is visible.
For those plants with limb and trunk breakage, prune only the jagged limbs or trunks to major crotches. Definitely use a copper based fungicide on the damaged plants.
If you are not sure how on the best pruning practices, check out our spring workshop on Planting and Pruning.
Depending on the damage you have experienced , you may need to make adjustments in irrigation and fertilization practices. Plants that have been severely cold-damaged will subsequently need less irrigation because they will transpire less. In fact, too much water may lead to death of roots which in turn can encourage bud rot and nutritional deficiencies.
Trees with little leaf damage can be watered and feed normally. Do wait until warmer weather to fertilize as starting too soon can encourage growth while another cold event could still happen.
Trees with moderate leaf damage have less leaf area and so the frequency of irrigation should be reduced. These trees should be fertilized more frequently—but at reduced rates when new growth begins.
Trees with few or no leaves should not be irrigated until signs of new leaf and shoot growth appear. Irrigating leafless trees may lead to root rot problems. These trees should be fertilized frequently at slightly higher rates once new growth begins. But if there has been wood damage the fertilization should be at a reduced rate that reflects the proportion of lost canopy.
And if we do get another visit from Jack Frost—here are a few more ways you can protect your plants:
1. Pitch a circus tent over your yard.
2. Have “Star Trek’s” Scotty beam your yard to Jamaica for the night.
3. Get a herd of sheep to blanket your plants
4. Hold a political party in your yard the night of a freeze. You’ll get plenty of hot air.