How to Kill Suckers of Holly

Holly berries Hollies are evergreen or deciduous plants that grow as ground covers, shrubs or trees. Image Credit: Jupiterimages/Creatas/Getty Images

Holly is not just for winter seasonal decorating: There are well over 400 species of holly (Ilex, USDA plant hardiness zones 4 to 6), including woody vines, shrubs and trees. The recognizable berries of the holly plant come in a variety of colors, from white to pink to blue to red. The leaves can be tall and smooth, or at the other end of the spectrum, display a larger, spinier look more in line with what you see during the holidays.

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Like other trees and plants, holly sprouts suckers; this is its way of growing more branches. Suckers appear at the base or higher up on the trunk, and while they are not very aesthetically pleasing, there are safe ways to kill the suckers without damaging the holly.

Types of Holly Suckers

Many plants and trees spread by suckering, but suckers can also emerge because of stress. These could be due to damaged roots, which can cause the suckers to come from the trunk's base. If the suckers are up higher, they are often referred to as "watersprouts." These sometimes show up where there are cracks or wounds from damage or pruning.

Other reasons for sucker growth include pests or diseases. Boring insects can get into trees and plants, affecting their ability to get water and nutrients. This diverted energy goes towards the suckers. Older trees can also be more prone to suckers, as decay starts to set in. Besides that. there are also trees that naturally grow suckers from their roots; examples include poplars, box elders and birch trees.

Removing Holly Suckers

If at all possible, remove suckers promptly. Although watersprouts can be trimmed with garden shears, it is best to grab the sucker between the index finger and thumb and to then twist it carefully off the plant. Pruning suckers helps plants and trees grow in height, rather than in width. It is also better for leaf and berry development. The sooner you prune them, the easier it is to remove them, but the best time to prune them is during their active growth phase.

If the suckers are growing from the roots, dig down with a gardening spade below the ground level. Check to see if the suckers are connected to another holly's root system; if you want to save the other holly, do not cut. Otherwise, trim the suckers off with gardening shears, making the cuts as level against the base of the trunk as you can. You can also try gardening products that are designed to eliminate the suckers without harming the plants.

Different Species of Holly

Holly can be evergreen or deciduous. One species of holly is known to be invasive: English Holly (Ilex aquifolium, USDA plant hardiness zones 7 to 9). This variety can be classified as a weed of concern in many areas, because its dense thickets can suppress growth and germination of native shrub and tree species.

This slow-growing evergreen can grow up to 50 feet tall by 15 feet wide. It may grow as a multi-stemmed thicket or a single-trunk tree. Its shiny, dark green leaves have sharp spines, with orange, red or yellow berries that are poisonous, plus small, whitish flowers.

American Holly (Ilex opaca, USDA plant hardiness zones 5 to 9) looks a bit like English holly, but its leaves are not as glossy. Two well-known cultivars are 'Greenleaf' and 'Carnival.' These are also smaller, topping out at about 30 feet high and 20 feet wide. Japanese Holly (Ilex crenata, USDA hardiness zones 5 to 8) is an easy-to-grow broadleaf evergreen, with a smaller maximum size of 10 feet high by 8 feet wide, with white flowers.