FALL & WINTER ROSE GARDEN CARE (November-February)
Albert Ford, Editor, MRS Newsletter
| Soil Testing | pH Correction | Winter Protection | Soil Mounding | Barriers |
| Hardwood Mulch | Other Coverings | Tool Care | Pruning | Bad Blackspot Last Year? |
It is a good idea to get a soil test of your rose beds periodically. If during past seasons you felt your roses lacked the vigor and flower production of former years or despite a regular and continuous spray program your bushes experienced more blackspot or mildew than in former years, perhaps you will want to get a soil test performed for you by the University of Maryland, Cooperative Extension Service at College Park. The mainly online resources are available through the Cooperative Extension's Home and Garden Information Center, including:
You will be able to pick up Soil Testing Information sheets,mailing packages, and many helpful publications at your closest Cooperative Extension Service Center.
A Saint Among Sinners
by Tom Conkwright
(click on the picture to see a larger version)
|SOIL ADJUSTMENT FOR LOW pH|
|Should the pH of the sample be low, which is most probable in this area, the gardener can apply dolomitic limestone anytime that the ground is workable. Bearing in mind that it takes several months for the limestone to become effective, it is preferable to apply it in the fall rather than to wait for spring. (See Sept-Oct, 1990 issue of the Newsletter, page 6.) Low pH during the growing season could be responsible for binding nutrients in a way that they--although present in the soil--were not available to the plant.|
|WINTER PROTECTION OF ROSE PLANTS|
|Probably the single most important activity for rose gardeners in this area during late fall and early winter is to protect one's roses from the very cold and windy months of winter, especially January and February. In 1989 we had one of the coldest and windiest Decembers that we have experienced in years, and as a consequence, many unprotected roses were killed. This devastation occurred in many gardens because the weather was warm through November and rose plants were not conditioned for winter, nor were they protected early enough. The plants were still actively producing foliage and flower buds in November with little or no inclination of going into dormancy. The unusually low temperatures and cold winds in December surprised the rose bushes and rosarians alike and many unprotected bushes succumbed or were so weakened that the alternating cold and warm weather of late winter and early spring did them in.|
It is convenient to be able to tie major rose activities down to some special event, like spring pruning when the Forsythia blooms. In this area, Thanksgiving can be the key for fall pruning and the application of winter protection.
|USE OF EXTRA SOIL|
|In my judgment, the best method is to mound soil around the crown to a height of about eight inches, Needless to say, a circle of soil eight inches high at the canes need extend out some distance to support the height and thus requires a fair amount of extra soil for each plant. Very few of us have such a supply, and as a consequence, for large rose gardens some other method would seem more appropriate. A word of caution on the use of soil. Don't scrape soil from around the plant for mounding purposes. To do so disturbs the roots near the surface and subjects them to winter weather peril.|
|BARRIER & OAK LEAVES|
| The next best method, again in my judgment, is to construct some type of barrier around the bush or rose bed and to fill the interior with oak leaves. The barrier can be made of a variety of materials. Newspaper can be used, or plastic (fiberglass) collars are available for the purpose. These collars are regularly advertised in The American Rose magazine.
The easiest method I have found makes use of 12inch "chicken wire" or wire mesh held in place with 1/4" to 3/8" bamboo sticks woven through the mesh and stuck into the ground. I grow my own bamboo and the sticks are readily available; however, they can be purchased at garden centers. Get the length that will accommodate the 12" mesh and will allow a few more inches to be pushed into the ground. If you prefer, longer sticks can be cut to length. Sometimes "chicken wire" is not available in 12" width, but the 24" width is almost always available and it can be cut in half with wire snips.
Oak leaves are recommended because they do not tend to compact and mat like other varieties. This compacting and matting tends to hold water close to the crown and can cause rotting of the canes where they emerge from the crown. Oak leaves, on the other hand, tend to retain their shape better, dry faster, and preserve air spaces between the leaves, thus lessening lower cane rot which would have to be pruned away in the spring. If you do not have an oak tree, neighbors will be glad to share theirs with you. The chances are they are going to put them in the trash anyway. Several rose growers I know who need oak leaves in the fall drive around the neighborhood until they spot an oak tree, the leaves of which have been bagged and set out for trash.
Some rose growers and writers recommend mounding soil around the plant--or plants in a bed--before applying the collar and filling it with leaves. In this area, I would reserve this treatment for the tender varieties such as `Brandy' and `Color Magic.'
One difficulty with the collar and leaves method is the required clean-up in the spring, removing the collars or wire fences and extracting the leaves. For this reason, some rose gardeners with a large number of roses prefer to use some type of mulch.
|HARDWOOD BARK MULCH|
|Hardwood bark mulch can be purchased by the bag or by the cubic yard. Used as winter protection, it is mounded around the crown of the plant to a height of eight inches. It protects the plant during the winter and is available in the spring as a mulch. This past year, I used pine bark mulch because hardwood bark was not readily available. It worked as well.
There are a couple of points to remember about the use of hardwood bark mulch. First, it should be removed from the crown gradually in the spring, but it can be left in the rose bed; it doesn't have to be carted away. It should be completely removed from the area just adjacent to the crown as the days become warmer because it is desirable to have the sun strike the crown as well as to promote good air circulation. Some feel this encourages basal breaks. Second, when applying fertilizer in the spring, rake back the mulch so that the fertilizer can be applied to the soil. The fertilizer, epsom salts (MgSO4·7H2O) , and whatever else we apply in the spring, should be raked into the soil gently before the mulch is replaced. Watering-in can be accomplished with the mulch in place.
Hardwood bark mulch tends to change the pH of the soil by making it somewhat more acid. If you use the hardwood bark method of winter protection, you should be prepared to be more rigorous about checking the pH and applying dolomitic limestone if required to raise the pH to 6.4 or 6.5. Those who regularly use hard-wood bark mulch find that it disintegrates over time and therefore it need be replaced periodically. They also apply dolomitic limestone each fall as needed because of the time required for the limestone to be effective.
|BEAN BASKETS & STYROFOAM COVERING|
| One member of the Society has used inverted bean baskets as a primary means of winter protection for over 10 years. Oak leaves or pine bark mulch are applied first around the crown, then the basket is put in place. Using this method, only one or two bushes were lost during the winter of 1989-90, although spring pruning of a number of bushes required cutting back to or near the crown.
It goes without saying that this method calls for pruning to a shape which can be covered by the basket. Storage of the baskets may also pose a problem for some. Meyer Seed Company does not normally carry them in stock but can order them in reasonable quantities for interested customers.
Styrofoam cones are available for winter protection, however, I do not believe they are used in this area; nor do I believe they are necessary, although some growers may have wished they had used them last year. Here again, they are usually advertised in late year issues of The American Rose.
|CARE OF GARDEN TOOLS AND SPRAY MATERIAL|
| The materials you have used for spraying your roses this year should not be left in the tool house or garage where they might be subjected to freezing temperatures. Store them for the winter in the basement or some other protected area. Make sure they are tightly capped and safe from inquisitive youngsters. Most of your unused chemicals from this year can be used next year. The shelf life of many rose care chemicals was covered in the Jan-Feb, 1989, issue of the MRS Newsletter.
Fall is the time to ready your tools for next spring. First, collect them together in one place, to avoid a frustrating experience if you wait until spring. Next, sharpen your shears, loppers, saws etc. and give them a good oiling, especially the moving parts. If you do not feel competent to sharpen tools yourself, take them to a specialist listed in the yellow pages of your phone directory. This task is better done now than in the spring when everyone wants theirs done.
|A NOTE ON THE LATE-SEASON PRUNING OF RAMBLERS..|
A question concerning the pruning of ramblers was posed to the Brooklyn Botanic Gardens. Their response was:
If you did not prune your ramblers this past summer, it is still not too late. Better now than in the spring. The same would be true of rambling Old Garden Roses, in which case removal of about a third of the growth is recommended.-Ed.
|Was Blackspot a Problem Last Year? (click here to download this article in Adobe PDF format )|
In winter it is too late to do anything about last year’s blackspot, but certainly well in time to make plans for better control next year. Ask yourself if you were sufficiently conscientious this past year with your spray program. Did you spray regularly? Did you cover both sides of the foliage? Did you alternate brands of spray periodically? Did you re-spray after a heavy rain? If you answer affirmatively to there simple questions and were unhappy about the amount of blackspot on your roses this year, it is time to rethink and redo your spray program.
The two principle tasks in the above are: good garden hygiene (clean up) and a regular spray program.?
|(Adapted from the November-December, 1990 MRS Newsletter)
updated October 30, 2006