One of the toughest things for a rose loving gardener to do is to say goodbye to our beautiful roses bloom smiles for the winter. However in cold climates we need to put our roses to bed for a nice winter nap. If we take time to do things right, we will see them burst forth with gorgeous bloom smiles again come next spring.
There are many different methods used by cold climate Rosarians like me, so I will just go over some ways that I take care of my roses for the winter. Our climatic conditions are always changing and thus when and how we do things must change as well. The timing of when we take steps to prepare our roses for the winter season is very important.
I stop giving my rose bushes any granular or long lasting feedings by the middle of August. Stop deadheading them by the middle of September and make the watering less frequent from the first part of September on. From the last week of September to the first week in October, I give all of my rose bushes a root treatment of two tablespoons of super phosphate, mix it into the soils and water in lightly. The super phosphate moves slowly through the soils and helps keep the root system strong through the winter months. These seemingly small steps help deliver a message to the rose bushes that it is time to slow down and store up energy for what can be a long and tough winter season.
Once a good hard frost has bitten the roses and the temps have become consistently cold so that the ground is somewhat frozen, I mound up garden soil around each rose bush. The mound is 6 to 8 inches in height, with roses that I know have made it through past winters just fine getting the 6 inches minimum mounding. New rose bushes that are taking their first winter test or roses I know to be winter tender get 8 inches. If I do not have extra garden soil saved up I buy some bagged garden soil at a local garden center for this use well before I actually need it. Make sure not to buy any garden soil that has fertilizer added to it as that is not needed or wanted for this winter mounding use. The fertilizer delivers a message to the roses that they need to keep growing and blooming very actively at a time when we want them to slow down and store up.
Once the rose bushes have all been well mounded, water the mounds lightly to hold the mound in place. Add a layer of mulch over the mounds. This helps hold the mounds in place by resisting erosion from the wind and wet snows.
Tip: The application of a good fungicide in late fall is highly recommended. It simply helps knock down any fungus problems that may try to overwinter and gain an upper hand on the rose bushes.
It is very important to note that the protection referred to within this article is to keep the rose cold once the cold weather sets in. That way, several warm days in the winter do not start the rose bush growing again, only to get zapped when freezing cold temps return. That fluctuation in temps is what can kill the rose bushes. It is very important to keep them in their cold weather dormant state throughout their winter dormant stage.
Prune your taller rose bush canes [typically the hybrid teas and grandifloras] down to half their height once they start to go dormant [consistently cold nights and hard frosts have arrived]. This will help to prevent the canes from being whipped by the winter winds and smashed by heavy snows that can break them off clear down into the ground. Do a thinning pruning on the canes of the floribundas, shrub roses, mini roses and such to help keep the heavy snow from smashing them down and causing damage to the canes. Wait until early spring for the major pruning.
Tip: Don’t forget about your rose bushes over the winter!! They still need some water to keep the roots healthy. Long periods of no snow and winds deplete the moisture from the soil. Water about mid-morning when the temps have started to warm. Never water late in the day as it will just ice up, plus the roots do not have enough time to take up and disperse the water enough so as not to cause problems when the temps dip down later at night.
Stan V. Griep has been a Colorado Native Rosarian for 40+ years. He is an ARS Certified Consulting Rosarian, a member of the Denver Rose Society, and the American Rose Society.
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