Knowledgebase
Leyland Cypress have turned rust brown during winter. #786208
Asked April 08, 2022, 1:39 PM EDT
Hi,
We live in zone 5b. Last June we planted a row of Leyland Cypress. They were growing and healthy-looking until this February when they started to turn a bright rust color from the top down. The trees are 2-3 ft tall almost completely rust-brown now.
Can these trees be saved? If not, I'm assuming I shouldn't replant Leyland Cypress at this place again.
Was too cold for them? We live in an area affected by lake effect weather and get quite a bit of wind, ice, snow, etc.
Could it be root rot? We get plenty of rain and snow here.
Is it an infection? Will this type of infection affect future plants -- such as arborvitae?
If I can't save them, what should I plant instead? Looking for a privacy barrier, windbreaker, and winter interest.
Many thanks,
Laura
Crawford County Pennsylvania
Expert Response
Leyland Cypress Hesperotropsis leylandii is Hardy to USDA Zone 6. Yours are slightly north of that and combined with record cold this winter indicates that this is probably frost damage. “There is no actual treatment for winter damage on Leyland cypress. Before pruning, allow the damaged tree to begin new spring growth. Often, if the damage did not injure the branch, new growth will emerge and the browned needles will drop off naturally. If new growth does not emerge, the branch was severely damaged and should be pruned above where green color is still visible. Leyland cypress trees are tolerant of heavy pruning, but if more than one-third of the tree is damaged, the tree may need to be replaced.” https://marylandgrows.umd.edu/2018/04/11/why-is-leyland-cypress-turning-brown-winter-took-its-toll/
LEYLAND CYPRESS DISEASES, INSECTS & RELATED PESTS https://hgic.clemson.edu/factsheet/leyland-cypress-diseases-insects-related-pests/
American Arborvitae Thuja Occidentalis is a recommended native alternative for Leyland cypress. Plant a variety of evergreens and deciduous trees and shrubs in a hedgerow for more interest and to avoid a monoculture (planting only one type of plant) which can spread pests and diseases.
