Disease-Free Roses

Having a Disease-Free Rose Garden by Diane Brueckman

‘Suñorita’ by Proven Winners ‘Bolero’ by Star Roses and Plants ‘Julia Child’ by Star Roses and Plants ‘Mother of Pearl’ by Star Roses and Plants

Since 1999 when the ‘Knock Out’ rose was introduced, the race has been on for more and prettier disease resistant roses. Most roses still need to be sprayed for black-spot but look for the new disease resistant cultivars. I know many of us (me included) have some old favorites that we really want to have in our gardens but we must care for them accordingly. A regular spray schedule is necessary to keep those roses happy and healthy. Check your local garden supply store for fungicides to prevent diseases such as black-spot, anthracnose and powdery mildew.

The best practice is to alternate two different fungicides with different active ingredients. This is to prevent the disease from becoming resistant to the chemicals. Always follow the directions on the container when using chemicals and take the precautions the manufacturer lists. Unfortunately, the heat and humidity we experience in the St. Louis area are perfect conditions for the disease to flourish.

Cultural practices can go a long way to keeping our rose gardens free of disease. One of the first things is to plant disease resistant roses. I mentioned the ‘Knock Out’ series of roses earlier, but that’s only the beginning of hardier, healthier roses. Look for Proven Winners roses. Most of you have heard of the Proven Winners plants. The Proven Winners are plants trialed across the country that have proven to be healthy and hardy. The Proven Winners roses are mainly landscape roses but have a variety of colors and bloom types, some also have fragrance. Look for other roses that have won the ARTS (American Rose Trials for Sustainability) award for sustainability and the AGRS (American Garden Rose Selection). These roses are trialed across the country and have proven to be disease resistant.

Another tip is to plant companion plants among the roses. This is especially effective with the more disease-resistant varieties and adds interest to your gardens as well. Keep the nitrogen levels low by using organic nitrogen instead of chemical sources that might release quickly, giving the roses a quick burst of lush green growth that encourages disease. A two-to-three-inch layer of mulch— mushroom compost, rotted manure or shredded hardwood, to name a few—will not only break down and add nutrients to the soil, but keep the weeds down as well. All of these tips also will work on the old beauties we love so well. You just need to spray to prevent those dreaded diseases.

The following is a list of some of the older and newer modern roses from before the ‘Knock Out’ revolution. I have found they tolerate our climate with grace and care:

HT – Hybrid Tea Fl – Floribunda Cl – Climber Gr – Grandiflora HM – Hybrid Musk

This is just a small group of the roses that grow well in St. Louis. The roses you choose go a long way to having a beautiful rose garden. A lot depends on the amount of time you want to spend caring for your roses. Choosing roses with proven disease resistance will make caring for your rose garden easier and more rewarding.

‘Mr. Lincoln’ HT ‘Memorial Day’ HT ‘Sunsprite’ Fl ‘Heritage’ DA ‘Iceberg’ Fl ‘Elina’ HT ‘Westerland’ Cl ‘The Pilgrim’ DA ‘Bolero’ Fl ‘Mother of Pearl’ Gr ‘Julia Child’ Fl ‘Penelope’ HM ‘Apricot Nectar’ HT ‘Queen Elizabeth’ Gr ‘Pretty Lady’ Fl

photo credits: Suñorita rose courtesy Proven Winners® Color Choice®, all others courtesy Star Roses and Plants.

Diane Brueckman is a retired rosarian with Missouri Botanical Garden, and currently owns Rosey Acres in Baldwin, Illinois. You can reach her at (618) 785-3011 or droseyacres@ egyptian.net.