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The Knock Out® Family of Roses
How much sun do my Knock Out® Roses need?
All of The Knock Out® Family of Roses need 6-8 hours of full sun every day. The more sun there is, the more they will thrive and produce flowers.
Does the Knock Out® Rose produce rose hips?
All of The Knock Out® Roses will produce hips sparingly but unlike some other roses, they aren't all that interesting looking. The flowers are the main attraction.
How much, what type and when do I fertilize my Knock Out® Roses?
The Knock Out® Family of Roses will perform beautifully even with out fertilizing.
If you choose to give them an additional boost, it is very important not to fertilize until after the roses are established and go through one bloom cycle.
Use a balanced fertilizer or fertilizer formulated for roses from your local garden center and apply after the first wave of flowering (be sure to follow the specified rates and method of application provided on the product label).
Make sure the soil is moist before you fertilize to avoid burning the roots. Do not fertilize late in the summer as this is the time the rose should be preparing themselves for dormancy and you do not want to create additional unnecessary new growth that will likely die back from the first hard frost.
My Knock Out® Roses had beautiful flowers in the spring but now none are blooming. Why?
The first wave of flowers will be abundant then the roses will typically have scattered blooms until another wave of heavy flowering occurs. This will repeat until the first hard frost.
Are there any climbing Knock Out® Roses?
Unfortunately, there is not a climbing Knock Out® Rose. We are always working with breeders and hybridizers to develop new Knock Out® Roses. You may want to try Morning Magic™, Winner's Circle™ or Brite Eyes™. All were bred by Will Radler who created The Knock Out® Rose. They are hardy to zone 5 and all are repeat bloomers with above average disease resistance.
How big will my Knock Out® Roses get?
Knock Out® Roses can grow fairly large in some parts of the country if not pruned. Periodic trims will keep them maintained at a smaller size (on average 3-4' wide x 3-4' tall). A once a year cut (to about 12-18" above the ground) in early spring (after the last hard frost) is also recommended for maximum performance.
Does a Knock Out® Rose smell like a typical rose?
The only true fragrant Knock Out® Rose is The Sunny Knock Out® Rose.
Do I need to deadhead my Knock Out® Roses?
All seven members in The Knock Out® Family of Roses are self-cleaning so there is no need to deadhead. If you'd like to deadhead your Knock Out® Rose to create a tidier look that's fine!
What colors or color combos are being worked on for the Knock Out® Rose?
We are always working with breeders and hybridizers to develop Knock Out® Family worthy introductions, in all colors, forms and habits.
I have several Knock Out® Roses that were growing great this year and then all of a sudden all the growth turned brown and dead. The stems on some of the plants are still green. Any suggestions to revive them or are they doomed?
If the roses can easily be pulled up from the ground, it might be gopher or mole damage underneath at the root level. Unfortunately if the roots are pretty chewed up, you'll want to purchase a new plant. You might want to look at a gopher/mole repellent in the meantime.
What type of soil do The Knock Out® Family of Roses prefer?
They prefer a balanced "neutral" soil, neither acidic nor alkaline. A desired pH level is between 5.5 and 6.5.
I have a Knock Out® Rose that has two different colored blooms. What's going on?
This sometimes happens when a variety is a mutation of another variety. Sometimes it wants to revert back to the original. It will happen randomly and not always, so enjoy the bloom while it lasts.
Do Knock Out® Roses grow faster when you deadhead them or is it better to just leave them alone?
Knock Out® Roses will re-bloom from spring to frost regardless of deadheading. Deadheading does offer a cleaner, tidier look. Often people choose to deadhead to remove the faded blooms.
My Knock Out® Roses wilted after they were planted, will they bounce back?
Could be transplant shock. Make sure you give them a good, long drink of water. When a plant wilts, it is usually very thirsty.
Is there a white Knock Out® Rose?
Yes, there is a White Knock Out® Rose. You can learn more here.
Planting & Pruning
Is pruning Knock Out® Roses the same as other roses?
In the Spring, after the last threat of frost has passed, cut back your roses (using hedge loppers) to about 12". This should make them grow to about 3'-4' tall by the end of the season.
For climbing roses, you want to prune your climbers in the winter or very early spring when the plants are dormant. Remove all suckers coming from below the bud union. Remove all dead or twiggy growth extending from the bud union. Cut all the flowering laterals that rise from the horizontal growing canes back to 2 or 3 buds.
Should I prune my roses each spring?
For best results, cut back Hybrid Tea, Floribunda, and Grandiflora roses in early spring (after the last hard frost) to 10" to 18". Remove all winter injured or damaged wood.
Prune climbing roses only as needed to control their size. Remove the older wood. Prune sparingly as the top is needed for bloom.
For shrub roses, to promote healthy growth and encourage lots of flowers, in early spring (after the last hard frost), simply use hedge trimmers or loppers to shear the shrub down to about 1/3 or 1/2 it's current height. It is okay if what remains is only about 12-18" above the ground.
For more detailed instructions, click here to watch our videos on how to prune.
Is it safe to plant in late winter/early spring?
We recommend you check your 10-day weather forecast, and if there is no threat of frost, then it should be safe to plant. For detailed instruction on how to plant a Knock Out® Rose, click here.
How close together can I plant my Knock Out® Roses?
All of the Knock Out® Roses should be planted on 3' centers. This allows room for them to grow and have good air circulation.
I did not know to prune my Knock Out® roses in early spring. Is it too late?
If they were just planted this spring and have already begun to bloom, we would advise against cutting them back hard. Try deadheading instead. If they have been in the ground a few years and are well established, it's okay to trim, but don’t take off more than 1/3 of the growth. Save the hard 2/3 trim until late winter/early spring.
Can I transplant my roses?
Yes, it is okay to transplant your roses. The best time to transplant is late winter or early spring while the plant is still dormant and before new growth begins to push out. Click here for more detailed instructions.
Is it okay to plant Knock Out® Roses in containers?
Yes, it is fine to plant Knock Out® Roses in pots. If you want to plant them in containers, transplant into a container 2 sizes larger than the size pot the plant was currently in to give it room to grow. Also, be sure to place the pot in a sunny location and keep them well watered. Depending on where you live, you'll probably need to bring them inside over the winter.
What is the ideal time of year to plant Knock Out® Roses?
You can plant Knock Out® Roses in the spring or the fall.
Pests & Diseases
What steps can be taken to treat powdery mildew?
Powdery mildew can be a common problem of roses, particularly when conditions are favorable in spring and fall. Powdery mildew is a fungal disease that appears as a soft white coating on stems, leaves, and buds of rose bushes. It commonly occurs when there are many overcast days with high humidity and mild temperatures. Generally speaking, powdery mildew becomes less of a problem after the arrival of summer which typically brings with it long, hot, sunny days. The mildew problem will go away with improved weather conditions. There are a few options for correcting the problem.
1. An application of horticultural oil should smother the spores and reduce spread of the problem. It is best to try this as soon as possible upon visible symptoms. An early sign of powdery mildew is a slight curling upwards of the foliage.
2. You could try trimming back the worst affected areas and wait for new, clean growth to flush out.
Voles are eating the roots of My Knock Out® Roses.
Traps and poisons are the two most successful methods of controlling voles. If you want to try the organic route, there is a product called Shake-Away Rodent Repellent which uses the scent of fox urine to discourage voles from burrowing into the soil beneath your roses. The product is in a powder form that can be sprinkled around the roses you wish to protect.
Japanese Beetles are attacking my Knock Out® Roses.
Pick each Beetle off and drop them into a bucket filled with warm soapy water. Putting a bird feeder nearby may also help. Japanese Beetles won't be detrimental to the overall health of the plant so if you can stand them, it's fine to leave them alone too. You may want to try a product like Milky Spores to control them--we recommend just pulling them off one by one though (not fun but effective)!
There are holes in the leaves of my Knock Out® Rose. They are not only on the edges and I don't see any beetles or other bugs. They are not symmetrical holes, either. Any tips?
The leaf damage you are seeing could be from what's called rose slug (also called sawfly). Look on the underside of the leaves. Do you see any tiny green inchworm looking critters? Rose slugs will chew the leaves of plants--leaving trails where they've munched through, but they won't be detrimental to the overall health of your Knock Out® Roses.
Do we need to protect our Knock Out® Roses from being eaten by insects?
Knock Out® Roses are not pest-resistant, but they are extremely tough so even if bugs get after them, they should be fine. You can use a spray product formulated for roses if the bugs are particularly bad in your area. The best way to remove Japanese Beetles is by hand though--pick them off one by one and put them in a container of warm soapy water. Placing a bird feeder nearby can also be effective!
The deer have eaten most of the blooms on my Knock Out® Roses. Will they bloom again or are they a total loss?
Knock Out® Roses are not deer resistant and unfortunately, as you probably know, when deer are hungry, they ll munch on anything. Don't worry though, Knock Out® Roses are really tough. They bloom repeatedly from spring through frost, so hopefully when it's time for them to bloom again, you will see more flowers. You may want to try a product like Liquid Fence to keep the deer away.
My Knock Out® Roses are starting to get black spot.
In some very humid, black spot prone areas, you may see some black spot. Don't worry--while the plant may drop some leaves, it won't be detrimental to the overall health of the plant. Make sure when you water your roses, that you water at the base of the plant. Watering overhead (with a sprinkler or hose), leaves water on the foliage which is an invitation for fungal disease. Your Knock Out® Roses will be much happier if you water at the base of the plant. Also, they prefer a long drink of water every once in a while rather than frequent small watering.
General Rose Care
I just planted my rose and it seems to have died.
Are your roses planted in a sunny location? They do need at least 6-8 hours of sun each day to flourish. If you planted in a sunny spot, it could be transplant shock. Try giving the roses a good, long drink of water. It can take at least a couple months for plants to get well established in their new location.
Besides keeping it well watering, you can try trimming off any of the wilted or damaged blooms to allow the plant to put extra energy into establishing new roots into the soil.
Do I need to deadhead Knock Out® Roses or Drift® Roses?
Both Knock Out® Roses and Drift® Roses will re-bloom from spring to frost regardless of deadheading. Deadheading does offer a cleaner, tidier look. Often people choose to deadhead to remove the faded blooms, so ultimately it is up to you.
My rose does not seem to have survived the winter. Is there anything I can do?
Are you sure this particular plant is entirely dead? Often after a difficult winter, a rose may appear dead, but will eventually regrow new canes from the base of the plant. Have you tried pruning it back to 6” or so to see if new growth emerges (which may take a few weeks)? By cutting the plant back, you’ll push all the energy back down into the roots which may help it bounce back over time.
If I live in an area with a harsh winter, what should I do to protect my Knock Out® Roses?
If you live in a harsh winter climate, you should do the following:
Add 2-3" of mulch, leaves, or pine/fir boughs around the base of the plant. A heavy snow cover will also help insulate and protect the plant through the winter. Also, the winter winds can really dry out the plant so you may want to wrap the plant with burlap. In spring, remove any extra mulch that may be covering the plant too deeply and trim out any dead or broken canes, also remove any burlap that you may have used to wrap the plant.
It's getting cold outside...what do I do with my roses that are planted in containers?
Don't panic! Leave the containers outside through the first few frosts then bring them inside and store in a cool, dark area such as your basement or garage. If you store your containers in the garage, remember to protect them from the winter temperatures that can come in as you open and close the door. Store your containers inside until the threat of the last frost has passed (typically in early spring). You'll want to check your roses periodically to make sure they don't dry out completely.
Any special instructions to keep the shape of my rose tree without getting top heavy?
Your rose tree should not get too out of control or top heavy in one season. Keeping it deadheaded after a flush of blooms will help for sure, or it can be sheared back as needed to keep it balanced. If sheared really hard, it may take several weeks for it to come back into full bloom.
Can tree roses be grown successfully in cold climates?
Yes. If other roses can be grown there successfully, then tree roses may also be grown. An important item to remember is that in areas where the temperatures fall below 10 ' F in winter, tree roses must have careful winter protection by wrapping them with insulating material to protect them from the cold and wind. In the colder areas where the temperatures fall below zero, the only adequate protection for tree roses is to lift them in late fall before very severe freezing weather and bury them in a trench covering them completely with a foot or more of earth.
Rose Rosette Disease
Where did RRD come from?
It was first identified on certain species roses in the 1940s in the Rockies. It spread down to the great plains and across the Midwest in the 1960s after the introduction of multiflora rose as a hedge and soil erosion tool.
What is Rose Rosette Disease?
Rose Rosette Disease (RRD) is spread by a tiny, windblown Eriophyoid mite. RRD is a disease, which can affect all hybrid roses, not just Knock Out ' Roses. We believe it may be a virus, but further research is needed to confirm this. RRD causes a variety of symptoms ranging from red growth to excessive thorniness, elongated shoots, deformed blooms and pliable canes.
Will pruning help reduce incidents of RRD?
Yes, we recommend pruning dormant plants just before new growth appears to help eliminate mites and their eggs that hide in bud crevices of cane-petiole axis from infecting a rose crop. We recommend cutting plants back by 2/3 their size.
What is the best way to eradicate multiflora rose?
We recommend you remove any Multiflora Rose that is in the area as it is a host for RRD and the virus-carrying mite. We recommend the use of frequent, repeated cutting or mowing at a rate of three to six times per growing season, for 2-4 years. Herbicides have been used effectively, but because of the long lived seed in the soil, follow-up treatments are likely necessary. Application of systemic herbicides to freshly cut stumps or to regrowth is also recommended. Or hiring a professional weed eradication service.
Does RRD survive in the soil after I remove an infected plant?
The virus does not survive well in soil but does in plant roots that may remain in the soil. It is okay to re-plant in the same area when you have successfully removed all the infected roots.
Can RRD be spread by pruning or cutting tools?
No, there is no evidence that RRD can be spread mechanically. But we recommend that all tools be cleaned and disinfested after pruning to avoid spread of other common rose diseases such as crown gall and other viruses.
What do I do if see an RRD infected plant?
Immediately remove the plant and discard of it by containing it in a sealed plastic bag. Do not add the infected plant to your compost bin or yard waste pile, and do not burn the plant, as this could cause the mites to "balloon" upwards and travel to other plants.
L.A. Dreamin’® Hydrangea
How often should I water my L.A. Dreamin'® Hydrangea?
Provide a good soaking 2 to 3 times per week for the first season, and then once a week after the plant is established.
Do I need to fertilize my Hydrangea?
Yes, fertilize once a year in late spring or early summer.
Do I need to prune my Hydrangea?
A light pruning in mid-summer is recommended but not needed. For the best flower power, do not do any heavy pruning after July.
How much will my Hydrangea grow?
L.A. Dreamin'® Hydrangea can grow up to 4-5 feet tall with a spread of 5-6 feet.
When is the best time to plant L.A. Dreamin'® Hydrangea?
Plant in spring or fall in a spot with morning sun and afternoon shade.
How do I plant L.A. Dreamin'® Hydrangea?
Dig a hole as deep as the root ball and 2-3 times as wide. If planting multiple Hydrangeas, space about 4-5 feet apart. Set the plant in the hole, fill halfway with soil and add water. Once water drains, fill the rest of the hole with soil. Don't plant too deep. Water thoroughly.
What zone is best for L.A. Dreamin'® Hydrangea?
L.A. Dreamin'® Hydrangea does best in zones 5-10.®
What type of soil should I use?
L.A. Dreamin'® Hydrangea thrives in rich, porous, semi-moist soil. Add compost to enrich poor soil.®