As spring tries to arrive, it is time to assess the condition of our fruit gardens. In many parts of the Midwest and East Coast, winter continues to try to hold us and our fruit gardens hostage. Snow and sleet continue to make what, we all hope, is the last appearance. Bitter cold does a tenuous dance with much welcome sunshine — it was 0°F first thing this gorgeous, sunny morning. Even the South has not been immune from this bizarre weather. In the West, temperatures have been uncharacteristically warm. Some areas need snow-melt and rainfall to replenish badly depleted aquifers.
One of the things to check for is rodent damage on trunks and limbs that were buried in snow. A modest amount of damage that does not totally girdle the trunk may set the fruit tree back a year or two, but hopefully it will heal and allow for a continued productive life. Fruiting bushes or vines that have suffered rodent feeding are best repaired by pruning out damaged branches and encouraging new growth near the base. You can substitute this as a more selective version of your normal pruning routine.
If the tree is totally girdled, however, a timely job of bridge grafting may save a mature prize specimen. The time to collect repair scions for that is NOW!
Cold Damage to Buds & Plant Crowns
Fruit buds need to be checked to see how many have succumbed to cold damage. You can do this by bringing in a few branches. Those you would have pruned out anyhow are ideal. Force the branches to begin blooming by keeping them in a bucket of water in a warm room for a few days. This will allow the buds to swell a bit, making inspection of the small reproductive parts easier. Once the buds have swollen, cut them horizontally with a sharp, single-edged razor blade. If all is green, all is good! Small brown or black spots in the center of the bud indicate dead or damaged pistils and stamens. Check several dozen buds and determine what, if any, percentage is lost. If the percentage is small — 10% to 20% — the likelihood of a reasonable crop still exists. In more cold-tender trees, such as peaches, the damage may be much greater this year.
Use your findings to guide you when pruning. Judicious removal of less or more wood will help you balance the potential crop load with the need to encourage renewal wood. Removing less wood will leave more fruit buds to produce a crop this season. Removing more wood, in the case where there has been damage to the actual branches not just the fruit buds, will stimulate new wood production with health fruit buds for future years’ crops.
In regions where severe winters are not typical and strawberries are not covered with a protective mulch, there is the possibility of crown damage this year. The extent and duration of low temperatures or drastic swings in your particular location will have the greatest bearing on any damage. You can inspect the crown by cutting it vertically (not horizontally, as you did with the tree fruit buds).
- Uninjured crowns will be creamy-white.
- Brown flecking indicates mild to moderate damage, the degree of brown being roughly proportional to the amount of damage.
- Dark brown, corky tissue is a sign of severe damage.
To help damaged plants recover, vigilant attention to proper watering and possible light applications of foliar fertilizer during the growing season will minimize stress to the plants and offer the best chance of a healthy crop. Timely bed renovation after harvest will also ensure a strong growing bed for next season.
For tree trunks that were not protected from southwest injury (aka sunscald) by painting last fall, the days ahead could be critical as air temperature remains cold, yet the sun’s rays warm the southern side of the trunk. If you did not take preventive measures last fall, you may still be able to intervene now. Installing a loose-fitting, spiral, plastic, mouse guard around the trunk may provide a bit of a buffer of modified air. The sun’s heat will mainly warm the mouse guard and not the trunk, thereby reducing the severe temperature differential between the shaded north side of the tree and the heated south side; that differential is what causes the trunk to crack.
If your trees do suffer damage, your recourse is, alas, limited. It used to be that painting the area with grafting compound was a suggested solution. However, more recent research has shown that this actually interfere with bark healing. Use the occasion to learn and take proactive steps in the fall. Buy The Backyard Orchardist: A complete guide to growing fruit trees in the home garden for all you need to know to keep your fruit trees healthy throughout the winter.