By Stan “The Rose Man” Griep, Master Consulting Rosarian, Rocky Mountain District of the American Rose Society
Keep an eye on soil moisture throughout the winter. Some light watering is usually needed to keep the bushes doing well for a great spring bounty of blooms. Water as early in the day as possible so that the roots have time to take the water up and disperse it throughout their systems before the deep cold of night sets in.
Sometimes snow melting and freezing cycles will cause ice caps over the ground around the rosebushes. This prevents moisture from getting into the soil for the roots to take up. Sprinkle epsom salts lightly around the bases of the rosebushes. It will help make holes in the ice caps, thus allowing moisture to flow. The epsom salts will also provide magnesium to the bushes which helps them create new basal breaks in spring.
In the first part of October give each rosebush 2 tablespoons of super phosphate. Work it lightly into the soil and water it in. This is not a typical feeding, rather the super phosphate moves slowly through the soils giving the root system a nice winter snack. This helps keep the root system strong as well as going towards having a nice flush of spring blooms.
Here is a checklist that I use once the rosebushes have gone dormant:
Clear all debris and old mulch away from the rosebushes. Place new mulch of choice around each rosebush to a depth of at least 2 inches. The super phosphate mentioned above could be added at this time as well, prior to the application of the new mulch. Be sure to use super phosphate and not triple super phosphate, as we do not want the extra strength product to send the wrong growth message for this time of year!
Mound all rosebushes for winter protection. An easy way to do this is to place a rose collar around the base of the rosebushes to be protected. Fill the rose collar 2/3 of the way with garden soil that have no fertilizer in them and very lightly water to settle the soil within the collar. Add a bit more soil due to settling. Top off with mulch, such as shredded cedar mulch or pine straw. Water very lightly again to settle the mulch.
Prune hybrid tea and grandiflora rosebushes down to half their current height. (The lower growing and bushy floribunda rosebushes, shrub and miniature rosebushes will need a bit of a thinning pruning at this time as well.) This pruning helps prevent cane damage, such as breaking off to the base of the bush due to strong winter winds, or a bush being smashed due to the weight of heavy snow.
Once the leaves have dried out a bit, they may be stripped off of the canes/bushes if desired. Or the foliage may be left on to fall off naturally. Any foliage that remains come early spring should be removed to make room for the new foliage.
Mound up soil or a soil/mulch mix around the bases of climbing rosebushes and shrub rosebushes also, use rose collars if desired and follow above directions to fill. Wrap climbing rosebush canes with a light fabric (light colored too!) to protect from harsh cold winds if desired. Climbing rosebushes on trellises against privacy type fences may not need this protection.
Protect your tree roses for winter as well. The desired graft on tree roses is way up at the top of the trunk. It is easily damaged and might die during deeply cold winters. I use plumbing water pipe insulation on the trunk of the tree all the way up and around the graft and out onto the canes. Then I wrap it all with a light-colored tree-wrapping product such as DeWitt Tree Wrap, a breathable white fabric.
Notes: Garden soil may be mixed with play sand to create a mounding soil that has better drainage capabilities. The play sand mixed in with the garden soil helps keep moisture flowing through the mounding soil and to the root zone, rather than holding it around the upper part of the bush where it may cause mold or fungus problems.
There is also an advantage to giving all of your rosebushes a “potassium drink” prior to their going dormant. Add 1 tablespoon of muriate of potash to 3 gallons of water; mix it well so that the muriate of potash is well dissolved. Give each rosebush two to three gallons of this mix four to six weeks prior to their going dormant. Giving the rosebushes this drink of potassium will give them a hardiness boost for winter. A great idea for tree roses as well.
Remember that we protect our rosebushes so as to keep them cold all winter long. Those warm strings of winter days can otherwise warm the roses up and make them think it is time to grow. Those warm and deep cold fluxuations will kill the rosebushes.
Author bio:With 40+ years of rose growing experience, Stan V. Griep is a Consulting Rosarian for the Rocky Mountain Region of the American Rose Society as well as the Denver and Loveland Rose Societies, a Colorado Native Rosarian, and is a member of the American Rose Society, The Denver Rose Society, and the Loveland Rose Society. He is a Cyber Consulting Rosarian for the American Rose Society, Colorado Gardening on-line and GardeningKnowHow.com as well as a freelance writer and speaker. An award-winning photographer, his latest book is available at Blurb.com: http://www.blurb.com/b/6909245-heavenly-gifts-for-the-soul
All articles are copyrighted and remain the property of the author.