The famous Knock Out roses

If you have ever walked into a plant nursery or the greenhouse section of Home Depot or Lowe's, you probably know about the famous Knock Out rose.  Released in the 1990s by the Conard-Pyle Co. and bred by renowned rose hybridizer William Radler, the Knock Out series of roses is, by a long mile, the most-commercially successful line of flowering plants in the history of the United States horticulture industry.  Millions of Knock Out roses are sold, planted, and admired each year.

Yours truly is one of the millions of gardeners who has come to appreciate the merits of the Knock Out roses.  For one, Knock Out roses are exceptional in their abilities to flower from May until Thanksgiving, essentially without interruption.  For an instant, high-impact dose of color that will return each year, Knock Outs are a hard lot to beat.  Unlike most other roses, Knock Outs are prized for their "iron-clad" disease resistance, relative drought tolerance, cold hardiness, and manageable size of approximately 4' x 4' at maturity.  If they have one fault, it is that they generally are lightly fragrant.  They also do not make great cut flowers since the blooms are, for the most part, smaller and less showy than your typical tea roses such as 'Chicago Peace' or 'John F. Kennedy'.

'The Original' Knock Out rose

Since the debut of the classic, red 'Original' Knock Out rose, the series has grown to encompass six other cultivars which give gardeners choices in terms of color and also, in certain cases, single vs. double blooms.  All cultivars exhibit the great flower power, excellent disease resistance, vigor, and cold hardiness found in 'The Original' red:

The 'Pink' Knock Out rose; image from Conard-Pyle Co.

The 'Sunny' Knock Out rose; image from Conard-Pyle Co.

The 'Double' Knock Out rose; image from Conard-Pyle Co.

The 'Blushing' Knock Out rose; image from Conard-Pyle Co.

The 'Rainbow' Knock Out rose; image from Conard-Pyle Co.

A beautiful shot of the 'Pink Double' Knock Out rose; image from Conard-Pyle Co. 

So are Knock Out roses worth the hype?  From my experiences, yes absolutely they are.  Over time, they are becoming increasingly affordable too, thanks to the sheer volume of plants produced each year.  I currently grow 'The Original' and 'Pink' Knock Out cultivars.  This year, I am hoping to add, at minimum, 'Rainbow' since it is considered the most floriferous of the bunch, which is saying a lot since they all flower very well!  I also will likely be adding a few more 'Pink' KOs, and may try out a Double too.

If you are interested in fragrance, you will want to seek out 'Sunny' for its good-quality, citrus-like fragrance which nicely matches its color and "sunny" disposition.  'The Original' is probably second best for its rather mild yet spicy-sweet scent.  From my experiences, all of the cultivars have some degree of scent but 'Sunny' and 'The Original' are the only ones that seem readily apparent.  As is the case with essentially all roses, the fragrance is strongest right before the petals fully open, just as they are transitioning from their more-columnar shapes to their wide, unfurled mature state.  

So if you are looking for a low-maintenance, high-impact landscape plant that may live longer than you do, head to the nursery this spring and pick up any one of the seven Knock Out roses:  you won't be disappointed!