Brown leaves - Ask Extension
Have nandina, cryptomaria, mahonia and laurels losing leaves that are turning brown. Some leaves are half brown and half their normal green color, but...
Knowledgebase
Brown leaves #925834
Asked March 11, 2026, 10:12 AM EDT
Have nandina, cryptomaria, mahonia and laurels losing leaves that are turning brown. Some leaves are half brown and half their normal green color, but many sections and branches are completely browned. Is this fungus, insect, or winter burn and what can I do to turn around the health of these plants as soon as possible?
Howard County Maryland
Expert Response
Winterburn is the most likely cause by far, and we've seen abundant and widespread examples of evergreen plant damage this year due to that phenomenon. Winterburn occurs as dry winter air and wind dehydrates the leaves when moisture in the soil is either lacking (we're still in a significant drought) or frozen and inaccessible to roots. Broadleaf evergreens tend to develop worse winterburn damage than needled evergreens, but we have seen injury to some of them as well.
A brownish color change or blush to various cultivars of Cryptomeria in winter is normal, but the browning pictured is not a normal color change and indicates that many branches appear to have died. Given the extent of the damage, pruning probably won't be practical, so the plant may need to be replaced instead.
Nothing can remedy winterburn; the damaged leaves cannot heal and will be shed by the plant on their own later in spring, usually as or after new growth emerges. You can trim some browned leaves off if they are too bothersome, but it's a tedious task for something as full as a cherrylaurel, and for compound leaves like Nandina and Mahonia (both invasive species, if you're inclined to replace them instead, which we recommend), you'd be removing leaf tissue that's feeding the plant if it's still healthy-looking and only some of the leaflets have browned.
There is no way to expedite the recovery of winterburned plants, other than making sure they are watered as needed if our weather continues to be abnormally dry. (Expanding new leaves requires lots of moisture.) Do not fertilize unless a laboratory soil test has measured a deficiency in particular nutrients. If the plants have been growing normally thus far, a soil nutrient deficiency is not likely.
Miri
A brownish color change or blush to various cultivars of Cryptomeria in winter is normal, but the browning pictured is not a normal color change and indicates that many branches appear to have died. Given the extent of the damage, pruning probably won't be practical, so the plant may need to be replaced instead.
Nothing can remedy winterburn; the damaged leaves cannot heal and will be shed by the plant on their own later in spring, usually as or after new growth emerges. You can trim some browned leaves off if they are too bothersome, but it's a tedious task for something as full as a cherrylaurel, and for compound leaves like Nandina and Mahonia (both invasive species, if you're inclined to replace them instead, which we recommend), you'd be removing leaf tissue that's feeding the plant if it's still healthy-looking and only some of the leaflets have browned.
There is no way to expedite the recovery of winterburned plants, other than making sure they are watered as needed if our weather continues to be abnormally dry. (Expanding new leaves requires lots of moisture.) Do not fertilize unless a laboratory soil test has measured a deficiency in particular nutrients. If the plants have been growing normally thus far, a soil nutrient deficiency is not likely.
Miri
