Last week I visited my favorite of all the rose gardens I’ve ever seen – the one at the U.S. Botanic Garden – and wasn’t disappointed. Why is my favorite, you may ask?
Roses with Beautiful Companions (and Surrounded by Mostly-Beautiful Buildings)
First, because they grow roses with an assortment of lovely groundcovers and even some taller perennials, so it’s a rose garden that looks, well, like an actual garden, not a collection of bare-bottomed specimens. See what I mean?
Roses With (almost) No Chemicals
Second, because they’re grown so naturally, and they educate visitors in more sustainable growing techniques and even expel roses that need too much fussing over, chemically. Great signage!
Problems and Solutions
I wrote to press contact Devin Dotson at the USBG with a multi-part question: “Do the roses now in the collection have any pests or disease, despite choosing appropriate types and using other good practices? If so, how, if at all, do you treat the problems?”
The staff provided this list:
- Rose rosette disease is definitely a challenge and is present at U.S. Botanic Garden and throughout D.C. We treat by removing infected plants and preventatively releasing predatory mites (Amblyseius swirskii).
- For black spot and powdery mildew, we try to buy resistant cultivars. We have not done any treatments for those, as it helps us evaluate which roses perform best in our climate.
- For Phytophthora root rot we use traditional fungicides and beneficial mycorrhizae to treat soil and plants showing symptoms and then also to pre-treat any plants that will be planted to prevent disease.
- For rose sawfly we do not use pesticides, relying instead of beneficial insects to help keep these in check and pruning leaves showing issue. We do use companion plants throughout the Rose Garden to encourage beneficial insects.
- Finally, spidermites are not a big issue for us, and we don’t treat them.
So Enjoy More Beauty Shots, Guilt-Free
Hybrid tea rose (Rosa ‘Lafter’). The USBG’s Conservatory in the background.
The yellow rose in the center is floribunda rose (Rosa ‘KORgeleflo’ Solero Vigorosa). The National Museum of the American Indian in the background.
From left to right: Foxi Pavement, Pink Grootendorst, Rosa gallica var. Officinalis, Bliss Perfuma (light, low one down front right)) behind Salvia ‘Caradonna’
Hybrid musk rose (Rosa ‘Sally Holmes’)
Floribunda ‘Bad Wonshofen’ Pink Emely
Thank you Susan – very useful information as I’m researching which roses to plant for next year
I am in N Wales but belong to a mostly US forum and one of their worst pests are thrips. How can these be tackled in a sustainable fashion?
Thank you, Susan. I had not heard about predatory mites. I’ve lost about 30 of my own roses to Rose Rosette, including some planted by my grandmother in the mid ‘40s, and we have not been able to keep roses safe in the other gardens I play in.I am glad to hear we may have a tool in the arsenal to deal with this horrible disease. Thank you for sharing.
Was interested to see a few shrub roses that had been hybridized in the prairie regions of Canada. Bred to survive our cold climate they also seem to be tolerant of the more humid regions of the country too. Nice to see public gardens displaying these tough easy to grow roses.
Thanks for sharing this. The U.S. Botanic Garden looks like a must see place if I ever visit D.C.
Great information, thanks!