Gardening: Hardy Knock Out roses bloom season long
There was a time when roses were the most popular flowers in the garden but during the years they fell from favor, having gained a reputation for high maintenance and lack of winter hardiness. But thanks to development of the modern “own root” shrub roses, such as the ever-popular Knock Outs that are relatively easy care and disease resistant, these lovelies are making a comeback.
Plant these seasonlong bloomers in soil rich in organic material that drains well, give them six or more hours of direct sun a day and make sure they get lots to drink and you are well on your way to success.
What a lot of homeowners don’t realize is roses that repeat bloom, including the ubiquitous Knock Outs, are big-time partiers — they don’t just like to eat and drink — they need to eat and drink to perform.
If Mother Nature does not provide it, in spring and fall a rose bush needs an inch of water a week. In the heat of summer it can take 2 to 3 inches to keep it happy and healthy, so a rain gauge is a valuable tool to keep track of your roses watering needs. Mulching the soil with 3 inches of pine bark helps keep the soil moist but still allows the soil to breath.
These heavy feeders are traditionally given their first feed after pruning in spring. Many gardeners use the flowering of forsythia to signal when to start cutting their roses back. Working granular fertilizer, according to the package directions, into the top inch or so of soil about every four to six weeks will do the job.
While some gardeners use chemical fertilizers — a balanced formula such as 10-10-10 is recommended — I prefer an organic-based, slow-release fertilizer, such as Espoma’s Rose Tone. Chemical fertilizers are high in salts that can suck the moisture from the roots of plants when they build up in the soil. Organic fertilizers, on the other hand, feed the beneficial organisms in the soil as well as the roses, and these organisms help the roses thrive.
Feeding roses in the heat of summer can put them in additional stress. However, a foliar shower of fish and kelp emulsion on a cool summer evening or early in the morning gives them a real pick-me-up.
We got a lot of dieback on our roses in the OPC garden this winter so we cut them back hard and they are rocking. We expect a great show for the June garden walk.
Nancy Szerlag is a master gardener and Metro Detroit freelance writer. Her column appears Fridays in Homestyle. To ask her a question go to Yardener.com and click on Ask Nancy. You can also read her previous columns at detroitnewscom/homestyle.