How do I get rid of these things?
I have a very large very old holly tree, when we bought this house a few years ago it had nice ground covering leafs under it and a couple vines. I would pull the vines out by hand when I saw them but this spring it seems the vines are out of control and I can’t pull them all out. What are my options? The roots of the tree are very shallow and I don’t want to hurt the tree, but I also don’t want vines covering my entire back yard. Help please. John
Montgomery County Maryland
There is an impressive population of these in this patch of ground. This appears to be seedling Japanese Honeysuckle; they can have differently-shaped leaves in various stages of growth. They are seeking better light and can scramble through and over each other and anything else in their path in doing so.
There are a few options for controlling this population, and doing any of them will also help remove the English Ivy that we can see beneath the Honeysuckle sprouts; this is also an invasive weed in the U.S., even it if was deliberately planted. At the very least, the English Ivy should be removed from the trunk of the holly to protect its health. For this, cut a section out of the stems climbing the trunk but only pull off the piece you cut out; the rest will die and come away more easily as it dies. It's likely birds are depositing the seeds of the Honeysuckle as they feed on the holly berries.
The first and simplest (though tedious) option is to hand-pull everything you can dislodge and discard it. Growth will re-appear because root pieces will be left behind and new seedlings might sprout from the disturbed soil. Each time it returns, it needs to be removed again to starve the root pieces left behind of their stored energy. Eventually, the plants succumb to starvation and die, but this may take a long time. If the holly is providing sufficient competition for light and water, then hopefully the process will take a bit less time.
You could try smothering the bed to starve the weeds of light, but you do not want something that would impede water and oxygen penetration into the soil or it will harm the holly.
The more effective route, though it still would require repeated treatments, is an herbicide. Active ingredients triclopyr or glyphosate are non-selective (affect anything they contact) and systemic, so the roots will be exposed to the chemical as well to kill the entire plant quicker. Do not spray the holly's trunk; instead, use only physical cutting and removal to control the ivy there. Read the product label for how to use; typically, they will include a "for harder-to-kill weeds" recommendation of a stronger concentration at the end of the instructions label - use that rate. It will also be very helpful to include a surfactant (also called a spreader-sticker or adjuvant), which allows the liquid spray to better adhere to the waxy leaves instead of mostly dripping off. Such products are sold separately and instructions given on the label regarding how to use them in the mix.
Our recommendation is to use two approaches - pull up everything possible first, and then use the spray mix mentioned above to control what returns. (Do not pull up the plants after spraying, as you need the herbicide to get absorbed into the roots.) If you cannot acquire any herbicide for awhile, then keep pulling it until the plants no longer return.
When you are finally down to bare soil, you can select one or more types of non-invasive groundcover to fill the space, or simply use a layer of mulch to discourage weeds. If mulching, be sure to keep the base of the holly trunk free of mulch. Groundcover options are diverse depending on the conditions for growth, presence of deer, desired aesthetic traits and so on. You could do perennial plantings with mulch in between them or a solid carpet of one or more types of groundcover.
Thank you so much for this great response. One follow up, Once I get down to the bare ground, should I only considering planting ground cover, or could I do something like a weed barrier and few inches of pea gravel around the tree?
You're welcome John.
We would not recommend landscape fabric (or any weed-barrier fabric) or gravel, but instead suggest either mulch or a non-invasive planting (either as a solid groundcover or as a mixed-plant garden-style planting with mulch in between plants. Standard bark mulch (bagged or bulk) should be fine or you can use what is known as "arborist wood chips" which are the coarser chipped tree wood, as they are also good for retaining moisture and adding organic matter to the soil as they break down. Bark mulches may be easier to use if applied around other plants, and the wood chips would be easier if used alone to cover a patch of bare soil with no plantings. Arborist wood chips can be inexpensive or free but can be harder to come by as there is a need to wait until chips become available (and gardeners in-the-know ask to get put on a waiting list for chip drops).