June is the time of glory for roses. Wandering in a blooming rose garden, those who think they have no room for these most glamorous of flowering shrubs may experience a twist of envy.
But no need. Small-space gardeners can have roses too: Just grow them in containers.
It's a good option not only for those who garden on balconies or tiny city lots. In a large yard, containers of roses make lovely patio plants that can echo the charm of a rose border beyond the lawn.
A rose in a pot is, admittedly, a bit more demanding than the average houseplant.
Even a miniature rose is a woody plant, like a lilac bush or a yew hedge or a tree. It evolved to grow in the ground for many years and to spend cold winters in a dormant state. In the close confines of a container it is likely to be a bit stressed and can't easily recover from tough breaks such as wilting from lack of water, according to Steve Hutton, president and CEO of Conard-Pyle Co., a major rose breeder and grower based in West Grove, Pa. And you can't bring it in the living room for the winter.
So your first decision should be: Are you going to try to overwinter this rose? Or are you going to treat it as an annual and compost it at the end of the season? There's no shame in that.
Doug Green, a garden writer in the Thousand Islands of the St. Lawrence River who runs a Web site at simplegiftsfarm.com, says he has grown many a rose in pots and never bothered trying to keep them over the winter. "Pitch a rose at the end of the season or give it to somebody else who can plant it in the ground," Green says. "It's 10 bucks." Even at $25, a shrub rose may be no more expensive than a fancy hanging basket of annuals.
If you do want to try overwintering the rose, make a plan before you plant.
You have several options: If you have an unheated garage or crawl space, wait until the rose goes dormant and loses its leaves in the fall. Water it thoroughly and move it into the garage where it will stay cold but the roots won't freeze hard, Hutton says. In early March, move it back outdoors and start watering it again.
If you have garden space, remove the plant from the pot once it's dormant and plant it in the ground, Green suggests. In early spring, as soon as the ground thaws but while the rose is still dormant, dig it back up and put it back in the pot. Or dig a big hole and sink the whole pot in the ground. Either way, a garden's span of earth will protect the roots far better than the thin walls and scant soil of a pot.
Dicier options include burying the plant and pot for winter in a pile of coarse, well-draining mulch, such as wood chips, or huddling a group of pots together in a window well or corner sheltered from the wind. "That might work in half of Chicago winters," Hutton says.
For hardy shrub roses, you should only need to prune out dead wood in early spring.
Whether your love affair is a summer's fling or a long-term commitment, all roses in pots have certain basic requirements:
Full sun. A rose needs a minimum of six hours of sun a day. In an urban situation, "it's sometimes hard to get full sun because other buildings are shading your balcony," says Fern Richardson, who gardens on a condo balcony in Orange County, Calif., and has a Web site called Lifeonthe
A good, big pot. Roses are pretty thirsty and need as much soil around the roots to hold moisture as possible, especially since containers dry out faster than soil in the ground. The minimum is 16 to 18 inches in diameter. Even miniature roses are best in larger containers, perhaps in a mixed planting with annuals, according to Eileen Carruthers, rose buyer at Chalet Nursery in Wilmette. Roses need excellent drainage, too, so make sure your container has a hole in the bottom to let surplus water escape.
Even moisture. Letting a rose's roots dry out can make it vulnerable to pests and diseases, according to Hutton. So check the soil often, and when the surface feels dry, "soak it," Green says. You'll need to water pots more often than roses in the ground, and especially often in hot weather.
A "self-watering" or "sub-irrigated" container can really help here. These pots have a reservoir beneath the soil from which the potting mix and the plant's roots wick up just as much water as needed to balance what evaporates. If you keep the reservoir filled, it evens out the water supply. Make sure the reservoir has an overflow to prevent overwatering and root rot.
Good soil. Actually, the thing to use is a soilless potting mix, rather than anything labeled "potting soil" or "garden soil." Potting mix will be light, fluffy and full of organic matter, so it both holds the right amount of water and lets any surplus drain away.
Regular feeding. Roses need nutrients, especially phosphorus, to fuel their bloom, and frequent watering washes nutrients out of pots. Green feeds his container roses with fish emulsion once a week; Hutton uses a slow-release fertilizer at planting time. Organic and slow-release fertilizers are safest, but if you use a fast-release water-soluble fertilizer, follow the directions carefully; too much can harm the plant.
Excellent air circulation. Some roses, especially the finicky hybrid tea varieties, are prone to fungus diseases that thrive in close conditions. So don't crowd your roses among other pots or patio furniture, and consider breezes when you choose a balcony spot. "If you don't have good sun and good air circulation it's really a beacon for pests," Richardson says. Remember, too, when placing your pots, that roses have thorns — and keep scratchy plants away from traffic routes.
Best bets for container roses are compact and disease-resistant. Many of the tough, hardy, reblooming modern shrub roses that are grown on their own roots, especially those described as "ground-cover types" for their low growth habit, should work well. But the popular Knock Out series will get too big. Here are a few suggestions:
Flower Carpet series. These widely available ground-cover shrub roses from Anthony Tesselaar International (tesselaar.com) mature to about 2 feet high and as much as 4 feet wide. Their single or double flowers come in colors from scarlet to amber, a sort of peachy gold. Their spreading stems make them attractive in a hanging basket, Carruthers says, though you may need to prune a bit during the season to keep them within the bounds of a balcony or patio.
Drift series. This popular series from Star Roses (conard-pyle.com) is a bit smaller, tidier and more mounded than the Flower Carpet roses, and well-suited for pots. They can mature to about knee-high and roughly 3 feet wide and come in several colors.
Miniature roses. Many roses have been bred to mimic the class shapes of long-stem rose blooms at just a half-inch to 1 inch wide on diminutive plants that often are sold in 4- to 6-inch pots. Because, like hybrid teas, they tend to be stalky, they may be best used as part of a mixed container with annuals that have the same need for full sun and steady moisture. The Blaze roses from Meilland International, such as "SunBlaze," are one widely sold series.
"Carefree Beauty." This shrub rose with pink single blooms bred at the University of Iowa by Griffith Buck is famously tough and easy to find. At about 21/2 feet high, it should be fine in a container, Hutton says.
"Sven." Part of the winter-hardy Northern Accents series bred at the University of Minnesota, this shrub with striking purple-to-mauve blooms matures at about 2 to 3 feet high.
"The Fairy." Dating from the 1930s, this classic polyantha type bears bunches of 1-inch wide pale pink roses, and reblooms in bursts after the first late June flush. "A wonderful, old, readily available rose," says Hutton. "It's vigorous, it can take some stress and it's not going to disappoint you." "White Fairy" also is available.
Tree roses. Also called a "standard," a tree rose is a compact rose variety grafted onto a tall, treelike stalk and trained and pruned into a globe. Rose standards are a classic look in formal gardens and can be underplanted with annuals for a drop-dead diva container. But because the graft between the plants is vulnerable, tree roses must be overwintered in an unheated but sheltered space, Hutton says.
— B.B.Copyright © 2015, The Baltimore Sun