Webs on bushes - Ask Extension
Our bushes have webs that started in the boxwoods and then spread to others. Last year we used the hose to spray the webs, which helped, but this yea...
Knowledgebase
Webs on bushes #874644
Asked June 25, 2024, 1:41 PM EDT
Our bushes have webs that started in the boxwoods and then spread to others. Last year we used the hose to spray the webs, which helped, but this year the webs expanded to more territory. We'd like to know what is causing the webs and how to eliminate them permanently. Thank you.
Montgomery County Maryland
Expert Response
These are spider webs (not spider mites), so they are not a plant pest and can be left alone. Spiders consume insects and are great garden predators that help to suppress pests, including mosquito adults and other biting flies, Spotted Lanternfly nymphs and adults, leaf-chewing beetles, and so forth. While blasting the webs with a hose can temporarily get rid of the webbing and might encourage the spider to move elsewhere, there is nothing that can permanently get rid of them, nor would we recommend using a pesticide to kill the spiders. (Such sprays are also not limited to spiders and could potentially also affect bees, butterflies, and other harmless or beneficial insects.) Shrubs that are sheared tightly, into dense and manicured shapes, might appeal to spiders (especially young ones, that tend to make smaller webs) as it gives them many more "tie-down points" where they can attach silk strands to construct the web. Not pruning heavily also helps to support long-term plant health, because very dense growth (like on boxwood) makes plants more vulnerable to pest and disease outbreaks.
Miri
Miri
Thank you Miri. My photos may not have adequately represented what is happening with the various shrubs. The webs appear to be binding up the leaves on the ends of a good share of branches (not just a few) and seem to be catching debris, and the leaves are becoming constricted and are turning brown particularly on the boxwood. Do you have any other suggestions?
Best,
Julia
Hello Julia,
Can you please share additional images of the damage you're seeing? In the original set of photos, we do not see any concerning damage to the plant. (Webbing will by nature catch and collect falling or windblown debris, and the brown leaves visible in the pics are those which already had been dropped by the plant as part of its normal leaf shed in spring or last fall, which is typical for all evergreens. They sometimes take a while to actually fall all the way out of the branches.)
The only pests that would create noticeable webbing while feeding on the plant would be spider mites and certain caterpillars (like webworms), neither of which we see indications of damage from. Hosing the webbing off or brushing it out with a gloved hand or a small broom is the only option to remove them for the time being, since we would not recommend spraying the plant with a pesticide.
Miri
Can you please share additional images of the damage you're seeing? In the original set of photos, we do not see any concerning damage to the plant. (Webbing will by nature catch and collect falling or windblown debris, and the brown leaves visible in the pics are those which already had been dropped by the plant as part of its normal leaf shed in spring or last fall, which is typical for all evergreens. They sometimes take a while to actually fall all the way out of the branches.)
The only pests that would create noticeable webbing while feeding on the plant would be spider mites and certain caterpillars (like webworms), neither of which we see indications of damage from. Hosing the webbing off or brushing it out with a gloved hand or a small broom is the only option to remove them for the time being, since we would not recommend spraying the plant with a pesticide.
Miri
