Stella Otto: The Backyard Fruit Gardener

Today's Tip: Mow vegetation short around the base of fruit trees and bushes to reduce winter habitat for rodents.

Mayhem in the Fruit Garden — Rodent Feeding and Winter Damage

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.

Rodent Feed­ing

Rodent feeding on hazelnut

Hazel­nut trunk dam­aged by rodent feeding

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

Apricot buds - tip separation

After a few days of forc­ing at room tem­per­a­ture these apri­cot buds are start­ing to swell

apricot flower bud

What we hope for — a healthy apri­cot flower bud!

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.

Peach bud swell

A peach branch with buds just start­ing to swell. Notice the sin­gle green shoot bud with a plump fruit bud on either side

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.

South­west Injury

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.


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