Why would my Honeycrisp apple tree have curling leaves?

Question:

Site location for honey crisp apple tree. I planted this last summer and the leaves curled about a month later. It is in southeast open location, had plenty of sun and water. The soil is sandy with rocks about a foot below and the ground slopes slightly. I want to know if the rocks below could be causing the problem and if I should move the tree in the spring?

Answer:

Liz Stanley, Horticulture Community Education Assistant, Knox-Lincoln Counties

Thank you for your question about your Honeycrisp apple tree that had curling leaves last year.
I would wait to see if the leaves emerge before deciding to move it or not. Moving a tree that’s already stressed doesn’t usually work out well.

Your site sounds OK. Apples need full sun, and well drained neutral pH soil. If the rocks were small, the roots should have no problem getting around and through them. If the rocks are large, (especially ledge), this could be a problem.

Here are some common causes of leaf curl:

  • Transplant shock. (Common when planting on a hot, sunny day, or late in the season.)
  • Not enough water or too much water. (Roots need oxygen.)
  • Fertilizer. (They’re salts, and can draw water away from roots, “burning” the leaves. Avoid fertilizer in the first season.)
  • Too much manure or compost in the planting hole. (Same as above.)
  • Planting too shallow or too deep. (Holes should be wide but not too deep. Keep the root flare and graft above the soil line.)
  • Phototoxicity from water or sprays on the leaves during hot, sunny days.
  • Fungal diseases like apple scab. (Honeycrisp is relatively resistant to scab.)
  • Apple borers in the trunk. (Common pest in home orchards.)
  • Vole damage on trunk.
  • Planting on ledge. (Ledge limits root growth and can heat roots.)
  • etc.

If you plant more trees this season, it might be good to do a soil test. Kits are available at county offices. For more information about planting and early care of fruit trees, visit our Growing Fruit Trees in Maine website.

Here’s a class that our fruit tree specialist is doing tomorrow:

Tues, Feb 23 6:00 – 7:30pm Growing Fruit Trees
Renae Moran will be teaching a class on home orchards (hobby fruit trees) offered through Lewiston Adult Ed. Cost is $7.00, Registration is required.  To Register with Lewiston Adult Ed.  The class will cover: Peaches, pears, plums, cherries and apples. Selecting the best varieties for disease resistance, cross-pollination, winter hardiness and for eating. The class also includes information on planting, pruning and harvesting.

I hope this is helpful, and your tree is OK in the spring!