Knowledgebase
Holly bush dying...is it red bugs or too dry or ?? #841895
Asked July 21, 2023, 1:58 PM EDT
Hello MSU super gardeners!
I am writing to you because Jonkers Garden Center of Holland, MI gave me your email for questions they cannot answer. I have a Holly bush our landscaper planted one year ago now July 2022 which was very healthy until about a month ago when we noticed the leaves turning brown and full branches dying. Around the same time we noticed all these red bugs nesting on the bush. They do not appear to be eating the bush, just sitting among the leaves. See attached photos below. Jonkers attempted to look up the bug but could not identify it so they referred me to you.
Jonkers suspects it is not dying due to the red bugs but bc of dryness or some other reason bc the leaves are uneaten. My landscaper said he knows very little about these bugs and advised we ask Jonkers.
We have a very full garden with many plants and none of them are dying. The plants under the Holly bush are doing fine despite all the red bugs running around in the mulch. We also have an underground sprinkler system which goes off daily unless it rains but I have never checked the root ball of the Holly for moisture.
Can you please advise? What are the bugs? Are they harming the Holly or is the Holly too dry? Or something else?
THANK YOU sooo much!! i love this Holly and hate to see it dying a slow death if we can do something for her!
Michele
Ottawa County Michigan
Expert Response
Based on the images you provided:
The red bug is a Boxelder bug. It frequently becomes a nuisance pest around homes and buildings near plantings of the boxelder tree, Acer negundo. Boxelder bugs usually do very little damage to plants and are of little concern to gardeners. In other words, it is the drought stress that is the problem with your holly.
Drought-stressed holly trees can show symptoms such as leaf scorch, leaf drop, and twig dieback. Drought Damage: Holly leaves often turn yellow or brown during a sudden drought period. Japanese hollies, particularly ‘Helleri,’ are not very tolerant to low soil moisture, particularly for the first several years after planting. Keep plants watered during periods of drought. Michigan State University Extension recommends watering the tree deeply and slowly once a week during drought periods. The challenge for homeowners and landscapers is deciding when a stressed tree is really a goner. Also, to tell if the plant is dead - scratch the branches with your fingernail and look for green tissue. If you see it, the branch is still viable. If brown, then the branch is dead. Prune all dead plant material, remove the excess mulch, look for the root flare around the base of the trunk, and keep the tree well-watered during dry periods. Monitor the growth of the plant.
Watering holly that has suffered a drought can be tricky. According to the University of Maryland Extension, watering frequency depends on the type of plant, the soil texture, whether you are caring for an established or a new plant, and local weather conditions. It is important to learn the specific water requirements of your plants, monitor local weather and soil conditions, and water accordingly. For newly planted trees and shrubs: Water immediately and thoroughly after planting. For the first two weeks after planting, check the soil moisture daily and water deeply if the top 6 inches of soil feels dry to the touch. During the first two years after planting, check the soil moisture at least once a week and water if the soil feels dry at 6 inches. This is especially important to help the roots of new plants get established in the soil. Be careful not to overwater. Many people have inadvertently drowned newly planted trees by watering them too often. Water should soak in quickly; your plants should never sit in a puddle of water for an extended period of time. This can lead to root damage. For all trees and shrubs: Water when the soil feels dry to the touch beneath the surface. Dig into the soil with a trowel, hand shovel, or screwdriver and check your soil at a depth of about 6 inches. Soil that is moist or damp to the touch is fine. If the soil feels dry, water the plant thoroughly
Bottomline watering is very important, and there is a chance that you might see dormant buds next spring.
The above information is from the below links:
https://hgic.clemson.edu/factsheet/holly-diseases-insect-pests/
https://extension.umd.edu/resource/watering-trees-and-shrubs
https://extension.umd.edu/resource/drought-and-excessive-heat-stress
Check out the MSUE article: Drought conditions begin to impact Michigan landscapes - Bert Cregg, Michigan State University Extension, Departments of Horticulture and Forestry - June 21, 2023 - Watch for common signs of drought stress on landscape plants. At this ink:
https://www.canr.msu.edu/news/drought_conditions_begin_to_impact_michigan_landscapes
Check out the MSUE article: Don't give up on drought-stressed trees - Bert Cregg, Michigan State University Extension, Department of Horticulture and Forestry - September 10, 2010 - Most deciduous trees, and even conifers, will drop leaves (or needles) when they undergo drought stress. This is part of the tree’s drought adaptation. The tradeoff is that the tree is also shedding parts that photosynthesize. At this link:
https://www.canr.msu.edu/news/dont_give_up_on_drought_stressed_trees
If you have any other questions, please let me know!
I hope this helps.
To Whom it may concern ~
OMGOODNESS!! Thank you SOOO much!! This was VERY educational and helpful!
Thank you for the links as well, I have not read them yet but I will. I have also
notified my landscaper...wish he had told me!
Blessings to you!
michele
