Tend to your Knock Out Roses this fall

Mariah Simoneaux, LSU AgCenter
Knock Out Roses

Pruning is a chore you might not think much about. Normally we prune as a way to control the size of a plant. When tree branches get a little too close to the house or hedges begin to get a little too tall we cut them back.

However, pruning at the right time can also stimulate vigorous new growth, increase flower production, and keep plants looking full and shapely.

Knock Out roses, like other everblooming roses, greatly benefit from two major prunings each year. The first of the major prunings should be done in late January to mid-February. This is the most drastic of the prunings, up to two-thirds of the bush may be removed if needed.

The second of the major prunings should be completed late August into early September. This fall pruning is not near as severe as the first, and generally bushes are only cut back about one-third of their original height. Apply a general-purpose or rose-specific fertilizer to your Knock Out roses after the fall pruning.

A sharp pair of bypass-type hand pruners can be used to make most of your cuts. Cuts should be made at an angle slightly above the nearest bud. Loppers may be required for some larger branches. Dead and damaged branches can be removed anytime throughout the year.

Wear sturdy leather gloves and long sleeves while working because the thorns on Knock Out roses can leave you with painful punctures and scratches.

In the right growing conditions Knock Out rose bushes can reach up to six feet tall and six feet wide. If the size of your Knock Out roses has become an issue, a good rule of thumb is to cut the bush back about one foot shorter than the desired height. If you want your rose bush to continue to fill in a space or form a screen a light pruning is all that may be required. There is no need to deadhead your Knock Out roses, but this can be done for a tidier look.

Knock Out roses are known for their season long blooms. They are available in a variety of colors, such as cherry red, bright pink, light pink, coral and white, and are widely available at most garden centers and nurseries. Add them to your landscape in late winter or early spring so that bushes can get established before beginning to bloom.

Mariah Simoneaux is the Horticulture Agent serving Ascension and Assumption Parishes. For more information contact Mariah at or visit the LSU AgCenter website at