Denny's Soapbox

Winterizing your Roses

There are thousands of different roses available to homeowners. All varieties have different tolerances to winter cold. Let’s discuss.

Average winters can still cause cane die-back to many varieties. This is the reason that you do your heavy pruning of the canes in early spring around the middle of March. The only exemption to this type of pruning would be climbing roses. The majority of next year’s flowers will be borne on the growth that occurred this past year. Prune back your climbers and you prune off a lot of next years color.

Winter hardiness varies with each rose and is related to the ability of each rose variety to manufacture its own “anti-freeze”. This is a genetic trait and it varies enormously with-in each group or classification of roses. There are certain species of roses like shrub roses i.e. ‘Knock Out’ and ‘The Drift series’ that are extremely winter hardy and need no additional winter protection while only a few of the modern hybrid teas, grandifloras, and floribundas can survive under severe winter conditions without winter protection. That’s why the vast majority of roses are not grown on their own root system.

Many roses, if allowed to grow their own roots, would not have a chance to survive our winters. The majority of roses are budded to the roots of wild roses that are very cold hardy. The bud union is that swollen area on your rose just above the ground. The bud union and the first 8 to 10” of the canes should be covered with leaves, additional soil, or mulch. Do this after your rose starts to drop its leaves. Do not prune your roses short this fall. That pruning should take place in mid-March. If your rose canes are extremely long, 5 to 6 ft or more, you can prune them back to 3 ft, no shorter.

Climbing roses are the exemption to any pruning. Climbers will bloom next year on the canes that grew this year. Don’t prune away your flowers. Only prune winter damaged or any canes that are overgrown in early spring.

Leave your mounds of winter protection in place till you see the buds start to swell in the spring. Then pull away the mound of protection and cut your roses back as explained above.

Added Tips

Stop dead heading your roses and leave any flowers on the plant in late fall. This will allow seed heads (rose hips) to form when the rose petals fall. This process sends a signal to the roots to shut down the growth and go to sleep for the winter.

Do not feed your roses any later than early September. Late feeding can cause the rose plant to produce late season new growth that won’t have sufficient growing time to harden off before winter causing the new growth to be easily damaged by winter weather.

When your rose leaves have all fallen, thoroughly clean up the rose bed by removing all the fallen leaves. This is especially important if your roses suffered from mildew or black spot. Since the disease spores can winter over on the old leaves, place the leaves in a bag and give to Rumpke.

Lastly, next year plant lots of ‘Knock Outs’. All the above does not apply to this great family of roses.