Tough Love for Roses

Less water, more blooms? The Huntington’s Rose Garden is more beautiful than ever, thanks in part to the smoky-red ‘Hot Cocoa’ roses (seen in the foreground), a hybrid by rose curator Tom Carruth.

Less water, more blooms? The Huntington’s Rose Garden is more beautiful than ever, thanks in part to the smoky-red ‘Hot Cocoa’ roses (seen in the foreground), a hybrid by rose curator Tom Carruth.

When Tom Carruth started as The Huntington’s E.L. and Ruth B. Shannon Curator of the Rose Collection in 2012, California was already experiencing record-low precipitation. Carruth decided to do his part by cutting irrigation to the historic roses to twice a week, for just 15 minutes each time. Three years later, The Huntington’s 4,000 rose shrubs are doing better than ever—bursting out in huge, beautiful blooms, filling the air around the Tea Room with a heady mix of rose scents that hint at lemon, apple, and clove.

It turns out that cutting back on water was just what the (rose) doctor ordered. Carruth analyzed the soil and realized it had become saturated and highly compacted. Wet soil chokes a plant’s roots, limiting its ability to grow, he says.

“Reducing water gives roses the tough love they need,” says Carruth. “Like most plants, roses like moist, not wet, soil that allows oxygen to reach their roots. And the plants become even more vigorous as they send out new roots in search of water.”

Carruth says roses aren’t fussy. His advice: “Build healthy soil and try some tough love in the form of less water.”

Carruth says roses aren’t fussy. His advice: “Build healthy soil and try some tough love in the form of less water.”

Carruth also added a thick layer of mulch, which helps to retain moisture and keeps soil and delicate roots cool. Mulch breaks down over time, further boosting soil health. He also makes a twice-a-year amendment of gypsum, a water-soluble form of powdered calcium. In heavy clay soils, gypsum helps particles of clay stick to one another, creating spaces between which oxygen can pass.

Finally, he cut out chemicals. “We’re a no-spray garden,” says Carruth. “We let birds and other natural predators take care of insects rather than using pesticides.”

The Rose Garden dates to 1908. In addition to being a beautiful place where the Huntingtons could stroll, it helped satisfy Arabella’s penchant for large and elaborate arrangements of freshly cut garden flowers. Today, it comprises nearly 1,200 different cultivars that span the history of rose cultivation. One of the oldest varieties, ‘Autumn Damask’, can be traced to the first century. By contrast, the award-winning, smoky pink-purple ‘Cinco de Mayo’ is a more recent addition, developed by Carruth himself during his days as a rose hybridizer at Weeks Roses before he joined The Huntington.

Henry E. Huntington stands under an arbor in the Rose Garden around 1916. The Huntington Library, Art Collections, and Botanical Gardens.

Henry E. Huntington stands under an arbor in the Rose Garden around 1916. The Huntington Library, Art Collections, and Botanical Gardens.

As rose gardeners in California and elsewhere adjust to water restrictions—but are loathe to forfeit gorgeous blooms and heavenly scents—they might want to follow Carruth’s tried-and-true water-saving tips:

  1. Cover beds around the bushes with three to four inches of mulch.
  2. Irrigate in the cool morning hours.
  3. Use overhead watering to wash grime and dew off plants, and to better hydrate them in hot weather.
  4. Convert sprinkler heads to low-volume models.
  5. Cut back on automated irrigation, giving supplemental water by hand to new plantings.
  6. Use a small spade or a soil probe to check soil moisture. When soil becomes dry two to three inches below the surface, it’s time to water it.

Carruth’s overall message is that roses aren’t fussy. Build healthy soil and try some tough love in the form of less water, he says. They might just reward you with a spectacular show of blossoms.

This watercolor of Rosa damascena, (of which ‘Autumn damask’ is one of two varieties) is by Pierre-Joseph Redouté, Les Roses, 1817–24. The Huntington Library, Art Collections, and Botanical Gardens.

This watercolor of Rosa damascena (of which ‘Autumn damask’ is one of two varieties) is by Pierre-Joseph Redouté, Les Roses, 1817–24. The Huntington Library, Art Collections, and Botanical Gardens.

Diana W. Thompson is senior writer for the office of communications and marketing at The Huntington.

15 thoughts on “Tough Love for Roses

  1. I now live in Colombia, MO an area with thick heavy clay soil beyond belief. Water is not the problem,but the clay is…perfect for bricks but not roses. Thanks for the tips.

  2. Thank you for the great advice from Tom. Perfect timing, as we all must reduce our water usage yet again. I am hoping that someone can answer a question in regards to watering “twice a week, for just 15 minutes each time”. Can anyone tell this reader how many gallons per rose this translates to? Is this 15 minutes for the entire rose garden or for each water station? I am getting the concept that it is a deep watering twice a week, but hoping for more specifics. Again, thank you!! And I love that it is a no-spray garden, by the way. Wonderful!!!!

    • Hi, Kristine. We’re passing your comments and question along to Tom. Check back soon to see what he has to say!

      Best,
      Kate Lain
      New Media Developer

    • Hi, Kristine. Here’s what Tom has to say:

      “Thanks for your question about how much water to give your roses. It’s hard to translate the information from our industrial sprinkler heads covering large areas to the needs of the home gardener watering an individual plant. I suggest you check with your local nursery or irrigation supply store. You could also try using a moisture probe to make sure your current watering cycle isn’t over- or under-watering the plants. I hope this helps.”

      Best,
      Kate Lain
      New Media Developer

  3. We have some old furniture that we were told were from the Huntington in the 1930s . I would love to see old photographs from those years to look for these pieces.
    Thank you!

  4. Thanks for the information. I am interested in the ‘no spray’ comment. I do not want to spray, but I find that even in this ultra-dry drought, my roses have a lot of mold especially on new leaves. Should I just leave this and hope it goes away? Aphids etc. are less of a problem – as you say, the birds and ladybugs etc seem to keep them under control. But the mold?

    • Hi Nick. Here’s some advice from Tom Carruth:

      This has been an especially bad spring for powdery mildew. The weather conditions have been perfect for this air-borne fungus. As soon as we get our summer heat, the fungus will dissipate.

      Powdery mildew thrives in still, moist conditions. To help keep it down, maintain good air circulation in your rose garden, thinning out shrubbery as needed. Heavily affected branches should be cut off. You can also choose rose varieties that are naturally resistant to powdery. Since we do not spray any fungicides, herbicides or insecticides in the Huntington rose garden, you can get some good notes as to which varieties have stayed clean under the intense pressure of this year.

  5. Oh — I should have mentioned: I live in Claremont, so we are just a little warmer than at the Huntington, but more or less the same conditions.

    • Hi, Nick. We’re forwarding your inquiry along to Tom and will hopefully have an answer for you soon. Keep an eye here to see what he has to say!

      Best,
      Kate Lain
      New Media Developer

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