“Knock-Out” roses are easy to grow, bloom constantly, resist disease, survive winter cold and “self-clean”. This means the spent blooms drop off and are replaced with new blooms, without tedious “deadheading” (cutting the old blooms off).
They all grow to about four feet tall and wide in a nice bushy shape without much pruning. They are so colorful and perform so well they can be used instead of shrubs in foundation plantings and hedges, with little maintenance except once-a-year pruning.
“Knock-Out” roses are “own-root” roses. This means that they are not grafted onto a rootstock from a different rose, but are the same plant from top to bottom. They won’t sprout non-matching suckers from the base of the plant like grafted roses, and the entire plant is hardy to zone 5.
Winter hardiness is what’s so terrific about tree form “Knock-Out” roses. In the past, getting rose trees through the winter was a gamble.
Elaborate precautions were needed to protect rose trees from freezing. Not so with “Knock-Out” rose trees, which are simply “Knock-Out” rose bushes grown on a trunk about three feet tall.
This puts the bushy part up at eye level, and allows flowers to be planted underneath for a striking effect. We call it “eye-level red”. Nothing is showier in the landscape, or more stunning in a large planter pot.
Tree roses thrive in locations with full sun all day or even in partial sun. We take special care when planting, adding peat moss and Rose Tone fertilizer mixed thoroughly with the planting soil. Staking for the first year keeps the plant straight. After that we just fertilize and mulch them like any other plant.
Once-a-year pruning to get rid of dead wood helps keep them shapely. You should remove any dead branches and cut the rest back to about a foot long, in late winter or early spring each year.
If you just can’t stand insects chewing holes in the leaves you can spray them with an all-purpose rose spray like Bonide “Rose RX 3 in 1” but they really don’t need it.
No rose is totally maintenance-free, but Knock-Out roses have proven to be tough survivors with very little attention.
If you’d like to try some, or want to add more to your garden, or make a gift of one to your favorite “black thumb,” see us. We have healthy, good-sized Knock-Out rose trees on sale right now. If you’ve given up on rose trees, think again because you can grow these easily.
Steve Boehme is the owner of GoodSeed Farm Nursery & Landscape, located on Old State Route 32 three miles west of Peebles. More information is available online at www.goodseedfarm.com or call (937) 587-7021.