Can I mulch away lesser celandine? It’s throughout my neighbor’s lawn and now making its way into my beds. Their gardening service suggested this.
Thick mulch may discourage celandine from emerging, but we find no research that shows this method is effective. Lesser celandine is a non-native invasive plant. It forms solid mats in very early spring and smothers our native spring wildflowers. It grows from tubers and tiny bulblets, which animals, gardeners and water runoff spread. Options are limited. If you want to try mulching, apply a 3-inch deep mulch a few inches back from the base of your plants. Digging up tubers is unsatisfactory, because invariably some are missed and readily grow new plants. The herbicide ingredient “glyphosate” is effective when sprayed on green leaves (plants go dormant in summer and disappear). Lesser celandine loves moisture and covers stream banks and wetlands, but in wetlands use only a glyphosate product specially formulated for use near water (Erasure or Rodeo), as regular glyphosate products kill aquatic animals. In beds, a very targeted application should work well. Hold the nozzle close to the foliage or use a brush or sponge, so glyphosate cannot contact your desirable plants. It is a total vegetation killer. You can also use a shield of cardboard or plastic to protect them. Mulch may be easier, but the question is whether it works. Try to figure out how lesser celandine is getting into your beds, since it doesn’t spread by seed or rhizome.
I see many brown leaves on my cherry laurel (and other plants, too). What is going on? I previously had a scale infestation on the cherry laurel, but I don’t see any scale now. And the other plants didn’t have scale. Should I cut off all the dead parts?
This is a big spring for winter damage. Not only did we have severe cold, but it was a dry fall and dry winter until recently. Dry soil in winter is tough on plants — especially on evergreens and broad-leaved evergreens most of all. That’s because evergreens continue to lose moisture through leaves and needles all winter, then suffer when they can’t replace this moisture from dry frozen soil. Don’t let your evergreens enter winter in dry soil. Winter damage produces brown margins, centers or whole leaves, but the vast majority of these plants are not dead. Winter-damaged leaves will fall off and be replaced with new growth. Be patient. Give them plenty of time to be sure they are dead before pruning. One test: scrape a bit of bark and look for green underneath, a sign of life. Leaf portions may fall off and look like insects have been feeding. Don’t be fooled. Insects (including scale) are not active in cold weather.
University of Maryland Extension’s Home and Garden Information Center offers free gardening and pest information at extension.umd.edu/hgic. Click “Ask Maryland’s Gardening Experts” to send questions and photos.