Monday, August 23, 2021

Caring for Your Trees After a Caterpillar Outbreak 

gypsy mothsDo you have trees in your yard that were defoliated during the caterpillar outbreak this year? (Read more about it here)

Most healthy trees can withstand a couple years of leaf loss from caterpillar damage. Long-term damage depends on the type of tree as well as how much defoliation took place:

  • Hardwoods – A healthy leaf-bearing tree should have grown new leaves by now, though leaves may be smaller than usual. If your tree lost all its leaves and does not grow any new ones by summer’s end, watch it in the spring. If it still does not leaf out next spring, it has died.
  • Conifers – If your needle-bearing trees lost more than 50 percent of their needles, there’s a good chance they probably won’t recover. Keep an eye on them in the coming seasons, and if you have concerns or think the tree could endanger a house if it were to fall, contact an arborist.

Losing lots of leaves in summer stresses trees and can weaken them, making them vulnerable to pests, diseases, or even competition from invasive plants that swoop in to steal the now-sunny understory space. If trees in your yard show signs of recovery, keep a close eye on them in upcoming months and watch for potential issues. Give them a little extra care when appropriate like:

  • watering in dry conditions,
  • weeding around the trunk,
  • mulching properly – just 1-2 inches deep (if you plan to mulch), and
  • scraping off invasive egg masses in fall/winter (if applicable).

If you have concerns, arborists are here to help.

If you’re a woodland owner who saw major forest defoliation, watch for new leaves this summer. If this is not the first year of the outbreak in your area and you have concerns for next year, contact a forester for a consultation.

Trees are pretty resilient, but sometimes they can use a little help from their human friends to get them through tough times. A watchful eye and a little extra care can go a long way in helping your trees get healthy again.

Melissa Hart photo

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NYS DEC

Information attributed to NYSDEC is taken from press releases and news announcements from New York State's Department of Environmental Conservation.




One Response

  1. Boreas says:

    Luckily, my small 3-acre property avoided much damage this year. But a large area on one side of me were heavily damaged. For some reason, the small brook that runs along the property line was the delineation.

    HOWEVER, my property was mobbed by adult moths laying eggs on my trees, so it is likely my trees will take a big hit next year. I plant to remove or kill as many eggs as I can by spraying horticultural oil, but I doubt I will find even half of them. Not much else I can do, other than try to control the outbreak next spring. I would suggest other property owners that didn’t get hit hard this year to try to minimizes the outbreak next year by looking for eggs. They are pretty easy to find, but the numbers of clusters are staggering on some trees, and each cluster may contain 1000 eggs.

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