Submitted By: Chris Hicks, UT Extension – 615-735-2900
Ornamental plants such as evergreens, flowers, and flowering trees are enjoyed by many homeowners. There are studies that indicate being surrounded by ornamental plants in the home and workplace can increase memory and concentration. On the other hand, fighting the weeds that are so often present can be a frustrating and time consuming experience.
Having a plan to deal with weeds even before you plant your ornamentals is a good idea. Picking out a good site, choosing your plants carefully, and preparing the site properly can help you avoid problems down the road.
The ideal time to control weeds is when you are preparing the site to plant. Controlling weeds after the fact is much more difficult and expensive. Prior to planting, weeds can be controlled by hand weeding, repeat cultivation, repeat applications of herbicides, or a combination of these procedures.
If the planting is going to remain in the landscape for an extended period of time, a landscape fabric covered with mulch may be beneficial for some ornamentals. This is especially true of shrubs, trees, and woody groundcovers. Be sure the fabric will not impede rooting or spread of the plants. Landscape fabric acts as a barrier to weed emergence but allows passage of water and air.
A mulch layer that is at least 2 inches thick will minimize the germination of annual weed seeds by blocking sunlight from reaching them. Do not use black plastic under the mulch, as plastic impedes water and air movement to the root zone of the ornamental plants.
Despite the best laid plans, weeds may still pop up. Escaped weeds may be controlled with a non-selective herbicide, where possible. If a non-selective herbicide cannot be used, then you are limited to hand removal of emerged broadleaf weeds, followed by additional mulching where the weeds were removed.
Emerged annual and perennial grass weeds can be controlled in most non-grass ornamental plantings with an herbicide that is selective for just grass weeds. Treat when grass weeds are small. Perennial grasses will likely require repeat applications. Be sure to read, understand, and follow the label directions when using any herbicide.
Having ornamental flowers, shrubs, and trees can add beauty and value to the landscape. Weeds can be a frustration for homeowners but with some advanced planning and a targeted approach, they can be dealt with. If you have questions about controlling weeds in your landscape, contact the University of Tennessee Extension office at 615-735-2900.
Mixed border including black eyed susans (Rudbeckia fulgida var sullivantii) ‘Goldsturm’, mexican feather grass (Nasella tenuissima), japanese barberry (Berberis thunbergii) ‘Atropurpurea’, new zealand flax (Phormium tenax) and coreopsis (Coreopsis vertic
