When is the best time to set out new Knock Out roses?
The Gardener’s Answer
Hello, Sue: For those of us gardening in Kentucky, Knock Out roses can be planted anytime except in the dead of winter. The ideal time for planting is during the fall when temperatures have dropped and they still have enough time to get their roots settled before the cold winter arrives. These prolific bloomers can certainly be planted in the spring as well as the summer months as long as they will be getting sufficient moisture. Planting in the middle of the summer is really just more maintenance on your part in terms of watering. We typically get enough moisture from Mother Nature during the spring for new additions, but our hot humid summer months are another story. If you will be in town to water or have someone who can water for you, I would say go ahead and plant them, otherwise it is better and less stressful on the roses to plant them in the fall. When you do add them to the garden, make sure they are being planted in a space where they will receive a minimum of six hours of direct sunlight. If they are planted in too much shade, they will not bloom well and become more susceptible to insect and disease problems. After you have found a good space in the garden for them, dig your holes twice as wide and just as deep as the containers they were purchased in. It is best not to fertilize for the first year so they can become established in the environment that exists naturally. This is especially true in the fall since we do not want to encourage new growth that can be susceptible to frost damage. Water them well and make sure they receive an inch of water per week for the first month. If we get sufficient rainfall then there’s no need to add additional water. It is always best to feel the soil for moisture before watering. The top layer of soil may be dry but a couple inches down may still have adequate moisture. Over-watering can be as detrimental as under-watering. A thin layer of mulch, no more than 2 inches, will help retain moisture levels, protect the roots during the winter months, and help prevent weeds.