Written by: Darla Carlock, Master Gardener and Riverwalk Rose Society Member

Proper rose care helps your rose bushes to flourish.  Roses can be a challenge but knowing when and how to properly care for them will ease some of that burden. It will also prevent several rose bush diseases.

Pruning is the first step in caring for your roses. You will want to remove anything that is dead, diseased, or diagonal.

Removing any dead canes– You will cut them down as far as you can to remove what is dead. This will save the bush energy. Cut at a 45-degree angle. If any cut stem is the diameter of a pencil or larger, you will want to cover with glue. You can use any white glue or wood glue. This will prevent any unwanted pests from entering the fresh cut cane.

Dead-heading-This is the process of removing spent flowers. Depending on the type of rose you have, they will try to fruit.  Most rose bushes, but not all, produce hips. This is a fruit that is rich in vitamin C.  Most rose bushes will either repeat flush or continuously flush (producing more flowers). The bushes will spend a lot of that energy in producing hips if the spent bloom is not cut.  When you remove spent blooms, you will want to cut the cane back to a spot where there are five leaves.  This ensures the best outcome from dead heading.  It will give a stronger cane to hold the next bloom. You will want to stop cutting off the spent blooms in September to allow the rose bush to go dormant for the winter.  If it is a hip producing bush, you can harvest the hip after the first frost when they will be ripe and the sweetest.

Diseased– There are many diseases that affect roses. Keeping your tools clean will help prevent cross contamination. Luckily, in Colorado we don’t get as many of those diseases that will kill your bush or spread to others. However, we do get powdery mildew, black spot, cankers and gall.

Powdery mildew and black spot can happen after a lot of rain and/or when watering roses from above where the leaves stay wet. It is important to remove all diseased leaves and throw them away. Do not use diseased matter in compost.

Powdery Mildew- looks like dried white powder on the leaves of the rose bush.
Black Spot– brown or black spots on the leaves.
Cankers– can enlarge and straddle the stem.  This can cause dieback from the tip of the stem. Cut below the site of the canker. Leaves could be affected by altering the appearance of the leaves. Leaf spots can range from purple to buff or grayish white with a purple rim. Discard all organic matter cut from this bush.

(Image courtesy of University of Maryland ext.)
Canker:The black area should be cut off and disposed of.

Gall: usually happens at graft sites. Crown Gall can be unsightly but the rose bush can still live for years. When gall is present at a fork above the soil level. It is caused by bacteria which is contagious. If the gall is above the soil, then it is like a tumor and you can cut below the level of the gall. It has not compromised the soil. Do not use this organic matter in your compost.

Diagonal– It is important to know that canes grow in the direction of the buds.  When pruning you want your canes to grow outward and not inward.  You will want to cut at a 45-degree angle ¼” above the outward facing bud. This will ensure your bush will flourish and keep the canes from choking each other out.

(Image courtesy of OSU ext.)

Watering– Roses need 1” of water every week during the hot summer months.  It is important to water from the base of the plant.  The roots need the water. Watering from above can cause water spots on light colored roses, as well as the above-mentioned fungal diseases.

Pests-The most common pests that affect roses are aphids, spider mites, and thrips. Generally, a good strong spraying off with water from a garden hose every couple of days will rid your bushes of these pests.  Another alternative is purchasing ladybugs or praying mantises for your garden knowing that both will leave when the food is gone. Neem oil products are also helpful in controlling these pests. Do not spray during the heat of the day.  This is best done either early morning or later evening.  It is an oil and during the heat of the day it will burn your plants!

(Image courtesy of USU ext.)

Diplolepis rosae-This is a type of spiny or mossy rose gall caused by wasp larvae. Unless there are significant amounts on your bush, there is nothing that needs to be done.  If you do remove it, be sure to put it in the garbage and not the compost bin.

Fertilizing- This can be done every 4-6 weeks during periods of growth. In Colorado, that would be from May through August. Fertilizer that is 8-10-8 is recommended.  Rose specific fertilizer will have that combination. Fertilizing after mid-August is not recommended due to the importance of letting the bushes go dormant for winter.

Planting- New bushes should be planted like that of a tree, into a bowl with the rim wider than the base.

• Grafted bush, you will want to make sure the grafted site is 1-2” below the level of the soil to help prevent the bush from reverting back to its original bush. It can still produce suckers from the original root.  Those can be cut or pulled off.  They will look different from the rest of the blooms.
• Own Root- these bushes have their own roots and will not change. It is not as important to how deep you plant them as long as the root ball is under the soil line to protect the root from injury.

If you have specific questions, you can contact a local consulting rosarian; they have specific rose education similar to a Master Gardener.  Also, you can attend local Rose Society meetings. Denver has the Denver Rose Society, Colorado Springs has the Pikes Peak Rose Society, and Pueblo has the Riverwalk Rose Society.  We all have pages on Facebook and are always happy to chat about the roses we love.