Roses: Beyond Knockout (GardenDesignOnline)

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A grand rose experiment started a couple of years ago at the US Botanic Garden ... and although it's still going on, some of the positive results are now in. The rule at this garden is no chemicals ... and if the rose doesn't perform well, it's simply tossed. The norm in Washington DC summers is hot and humid .. and more hot and humid -- probably the very worst climate for roses.

When 'Knockout' roses came along, they were definitely an answer because they survive the climate, bloom from spring until frost, and are not disfigured by black spot. The problem with 'Knockout' is that it's almost all you see in a lot of mid Atlantic gardens these days, and with no fragrance to mention, it, well, just doesn't stand up in the beauty department.

I went to a heartening lecture a couple of weeks ago by USBG Executive Director Holly Shimizu, and the news is that there are dozens of roses that are doing perfectly well in the summer weather. One of them is 'Pretty Lady,' shown above. Also doing well are a lot of the David Austin Roses, including 'Graham Thomas' and 'Heritage.'

According to Shimizu, several miniatures are doing just fine, and one of the most floriferous is 'Gourmet Popcorn," at left. Some of the other staff favorites include the rugosa 'Purple Pavement' and the polyantha 'Marie Pavie.'

Unfortunately, the official flower of the District of Columbia -- 'American Beauty' -- has been removed from the garden because it simply didn't stand up. (And you can read the history of 'American Beauty' in the New York Times, here.) The floribunda 'Gold Magic' suffered total defoliation, although it kept its flowers, and the much-touted 'Just Joey' was also removed because of disease problems.

The next time you're in DC, it's well worth a visit to the Rose Garden (located in the National Garden adjacent to the USBG conservatory). You'll be able to write down the names of the roses that are doing well ... and if they are doing well in DC, they'll surely do fine anywhere in the country. And FYI, USBG does use all-organic products on their roses, which they get from the Organica Company in Norristown, PA: PGA Plus, Agroroots, Plant booster, and K+ Neem Insecticide, which is made from potassium salts and fatty acids from cold, pressed Neem Oil.