October 17, 2005 at 12:51 p.m.
It’s time to put those roses to bed!
It’s time to put those roses to bed!
Many roses sold as hardy in Minnesota are actually crown hardy, the plants may die back to the snow or soil line, but will regrow and bloom vigorously from new canes initiated from the base of the plant. Many nurseries are now offering these roses labeled as 'own-root'. By rooting cuttings of cultivars, instead of grafting, the roots and the shoots are genetically the same (the rose is on its own roots) and winter survival can be enhanced.
When plants suffer severe dieback, any emerging shoots from the own-root plant will still be the desired cultivar. With grafted roses, if dieback occurs beyond a graft, the emerging shoots will be from the rootstock.
Crown hardy roses can benefit from insulation around the base of the plant to prevent excessive cane dieback. Add an extra 4-12" of mulch around their base after the ground is frozen and gradually begin to pull it back in the spring (early April?) before new growth is too far along that it gets damaged from handling.
Some roses, such as many of the pure rugosa hybrids, are hardy enough to withstand Minnesota winters on their own with little or no cane injury. It is often best to just leave them alone and treat them like any low-maintenance landscape shrub.
With both of these types of roses you should discourage succulent late-season growth by ending nitrogen fertilization in late-July, not pruning heavily in late summer or fall and discontinue deadheading spent blooms in September.
Hybrid tea, grandiflora, and floribunda roses are not reliably crown hardy here and depend on insulation for consistent survival. The "Minnesota Tip" is one of several proven methods for protecting these roses against early freezes in the fall, the bitter cold of winter, and the dangers of the thaw-freeze cycles in the spring. This is also the method to use to protect 'tree roses'. What follows is a simple series of steps for preparing your roses for the tipping process and the process itself as presented by the University of Minnesota Extension Service.
Protecting roses actually begins in mid-summer with ensuring that the plants enter the fall months in the best of health. They should be well-watered, properly fertilized and kept pest-free. Soon after mid-October, preparation can begin for tipping the roses.
1. Water generously one or two days prior to tipping to keep the soil in a moist, workable condition.
2. The day before tipping, give the plants a good dormant fungicide spray such as a liquid lime-sulphur material.
3. Tie the rosebush canes together to allow easier handling.
4. Avoid pruning the bushes. Open wounds on the canes may not heal properly, as cold weather can inhibit the formation of a protective callus.
5. Dig a trench, starting away from and working toward the base of the bush. The trench should be as long as the bush is high. The width and depth should easily accommodate the bush or bushes. Pull the soil away from the shank (i.e. the root stock area between the bud union and the main branching of the root system) to facilitate tipping of the rose. Basically, this refers to the area just under and up to the surface of the soil. The objective is to loosen the soil and area around the roots so that none of the critical plant parts crack or break during the tipping process. A spading fork is helpful for loosening the soil around the roots.
6. When the trench is ready and the roots of the bush are loosened, use a spading fork to push the bush into the trench. Use the spading fork (or a rose-tipping helping hand!) to hold the bush down while covering it with 2-3 inches of soil.
7. Cover the soil with about 18" of loose leaves or other covering such as marsh hay.
Next spring, start uncovering the rose bushes about April 1. Begin by removing the leaves and then gradually remove the soil as it progressively thaws. On or about April 15, raise the plants to an upright position and syringe the canes often with water to prevent them from drying out. Once the plants have been lifted, spray with a good all-purpose fungicide and insecticide and make sure they are adequately watered.
Upcoming Classes and Events
The last free class sponsored by the Chisago County Master Gardeners this year will be at the Senior Center in North Branch October 25. The hour-long session begins at 6:30 p.m. For more information call the Extension Office at 651-674-4417.
Buckthorn and Other Invasive Woody Plants, presented by Dr. Patrick Weicherding, Regional Extension Educator from the Andover Regional Center.
Did you know that nearly all woody plants which have become invasive have been introduced intentionally by horticulturalists, botanists, foresters, or gardeners? Buckthorn, for example, was introduced into America in the mid-1800s as a very popular plant material for formal hedges. The nursery industry has stopped selling it, but it is still very common in older neighborhoods and it has become a major problem in the landscape. If you want to learn more about invasive woody plants and their control then plan to attend this seminar. You may also bring samples to be identified.
In Your Yard and Garden
As the gardening year draws to a close, now is the time to begin to plan for next season. Sanitation is essential for good plant health management. Removing diseased plant material this fall will help prevent disease problems next spring. Many disease-causing organisms can survive the winter in infected plant debris. Plowing or tilling under crop debris can also help prevent over-wintering of plant disease causing organisms. Do not compost diseased plants! In Minnesota, compost rarely reaches the temperatures required to kill most plant pathogens.Be sure to discard the material properly, by bagging it or by burning it if this is permitted.
Before you begin your sanitation program, be sure to take notes of what did and did not work, what will need dividing in the spring, and what needs to be moved. If you haven't been keeping a gardening log, now is a good time to start! You can take notes about problems and research potential solutions over the winter. Pictures will be a great reminder next year of how well the plants fill in.
Ways to Access Information
The voice mail is checked year round. Leave a message at 651-674-4417, ext. 18, and a Master Gardener will return your call.
www.extension.umn.edu/county/chisago––check out the 'Hot Topics' box in the middle of the page for current Chisago County Master Gardener news and events.
You can also click on 'Ask a Master Gardener' next to the cute little flower on the right hand side of the page. Here you can search 1,000's of answers from Master Gardeners around the state. If you don't find your answer you can submit a question online or search for University publications.
Bell Museum of Natural History: For information about snakes, skunks, raccoons or other wildlife around your yard, call the wildlife information line at (612) 624-1374 or http://www.bellmuseum.org.
To see the latest Yard and Garden newsletter, go to: http://www.extension.umn.edu/yardandgarden/YGLNews/YGLNews.html.
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