If you don’t have garden space or you’d like living bouquets you can shuffle around your home, consider growing roses in pots. Even if you already have a rose garden, there’s something special about the intimacy of scented roses blooming in pots near an outdoor seating area, dangling from a basket at nose level, or even placed in a corner of a sunroom.
However, potted roses aren't as easy to grow or as productive as they would be in the garden. The following expert tips explain the best way to handle watering needs, whether or not you should fertilize, how and when to prune, and how to deal with pests and diseases so you can get the most out of your container roses.
- Gregg Lowery is curator at The Friends of Vintage Roses, a nonprofit organization that maintains a collection of thousands of rose varieties in Sebastopol, California.
- Charles Quest-Ritson is a garden columnist for Country Life magazine, and co-author of the RHS Encyclopedia of Roses.
- Guoliang Wang is a professor of horticulture with the Jiangsu Provincial Commission of Agriculture and author of Old Roses of China.
Tips for Growing Roses in Pots
"The problem with pot culture is that it requires thoughtful maintenance," says Gregg Lowery, curator at The Friends of Vintage Roses, one of the world’s most influential and complete rose collections.
Charles Quest-Ritson, Country Life garden columnist and co-author of the award-winning RHS Encyclopedia of Roses, goes further: “In the long term, you will never have anything to match roses grown in garden soil, or in the soil of a glass house.”
Still, you can get worthwhile results if you check your expectations and use these tips to care for roses growing in containers.
1. Keep a careful watering schedule.
“Watering is the number one concern,” says Lowery. “It's not on your schedule. It's on the plants’ schedule. That's the hard part for all of us.” Quest-Ritson also ranks watering needs as the biggest challenge with growing roses in pots. Both under-watering and over-watering can be tricky to avoid. The symptoms for both look similar: you’ll notice any soft growth start to wilt. If it's overwatering, there's often an unpleasant odor like rotten eggs.
Overwatering is the easier of the two to handle. If your potting mix and your container both drain well, it’s harder to overwater a potted rose than it is one in the garden. It will be a bigger problem for roses grown indoors since they require a saucer or cachepot that protects your home but limits drainage. Self-watering pots may also keep conditions too moist for roses.
If possible, take indoor roses out of their saucer or cachepot and water them outside or in a sink. Let all of the excess water drain for several minutes before putting them back in place. The same is true for outdoor roses grown in decorative pots without drainage.
In most cases, your biggest problem will be watering enough. During the hottest, driest parts of the year, Lowery makes sure outdoor roses get watered almost every other day in order to meet their watering needs. “If they’re not, they suffer terribly.”
Don’t wait until your roses start to wilt to water them. They may snap right back and look healthy, but you won’t get as much or as frequent bloom. Water deeply each time until water completely saturates the potting mix and flows from the drainage holes. Try using a moisture meter if you aren't sure how much to water.
2. Pick the right rose.
The roses you choose will determine performance and style. Your choice will also determine how much work it will take to grow and maintain them. Lowery recommends dwarf polyantha roses. “Because they’re dwarf, they can actually live a long, long time very happily and healthily in a good sized pot,” he says. He also recommends their equivalents among petite groundcover roses and miniatures.
However, pots make it possible for almost anyone, anywhere to grow any rose they want. In fact, for adventurous gardeners, the constraints of container culture can be a useful tool. A large climber or rambler that you love but don’t have space for can be encouraged to grow as a shrub or short climber in a pot. Or you can corset a suckering rose that would normally spread aggressively through your garden. Be aware though that in most cases any rose that isn’t compact will require more care and won't be happy in a pot for long.
Roses come either own-root or grafted onto rootstock. Quest-Ritson ranks rootstock as one of the top four problems for container culture because “the rootstock occupies too much space within the pot.” To create a better balance of roots and top growth in the limited space of a container, opt for own-root roses. That will also improve cold hardiness.
3. Use a rich, well-draining potting mix.
Seemingly everyone who has been growing roses in pots for a few years has their own special potting mix with a list of exotic-sounding ingredients. Guoliang Wang, a professor of horticulture with the Jiangsu Provincial Commission of Agriculture and author of Old Roses of China, cites a formula from a 1,000-year-old Chinese rose guide: “Fired soil, surface soil from the forest, vegetable garden soil, and fermented organic matter.”
Quest-Ritson says a potting mix doesn’t need to be anything special, “but it must be rich–full of nutrients.” Most experts now prefer a sterile soilless potting mix. You can find it premixed at nursery centers or online. Depending on what you find, you may still want to amend it with peat moss, vermiculite, sand, or perlite to as much as 25 percent of the final blend to improve drainage. Lowery especially recommends mixing in finely ground volcanic rock as 25 percent of the final mix.
4. Select a pot with enough space and good drainage.
The shape, size, material, and color of your pot impacts almost every other aspect of container culture. For example, taller pots drain better, darker pots heat up and dry out faster, unglazed terracotta aerates soil better, and plastic or other synthetic materials tend to be durable but fade in the sun. Whatever container you choose, make sure it has several holes for drainage in the bottom.
“I will never, ever put a rose in a pot that has only one hole in the bottom,” says Lowery. “The problem is that when rose roots get big enough they go straight through the hole. And they get big enough that they can block the hole. I've lost plant after plant after plant growing in terra cotta pots that way.”
If your pot only has one hole–or no holes–use a drill and a large bit to make more. Cachepots and architectural containers like concrete urns are the exception. In either case, you don’t plant directly in them. You plant your rose in a pot with drainage holes and then slide that pot inside the decorative container. When you water, pull the pot out and let the water drain from the bottom for a few minutes before replacing it.
As far as the ideal container size, Lowery says 7 gallons is a “lifetime size” for a small rose like a dwarf polyantha “but even if you take a rose up to a 15 gallon container...they look fabulous for a few years and then they decline.” Of course, nurseries often keep roses in their modest-sized nursery pots for a couple of years and you can too, but expect it to plateau and decline rather than continue to develop.
Should You Use Rocks for Drainage?
You’ve probably heard about drainage layers of rocks, sand, or pot shards–either that you need them at the bottom of your pot to improve drainage or that they’re one of the groundless gardening myths floating around. There’s some debate around this, but unless you’re intrigued by the science and history, you can skip it because your plants will be fine either way.
“I am now confident that drainage layers do tend to reduce soil water retention in the majority of cases,” says Avery Rowe, an independent researcher who has investigated the question. “Personally, I never use drainage layers, because it's an unnecessary extra effort that makes only a small difference.”
Steve Reiners, a professor of horticulture at Cornell University, says you don’t need extra drainage anyway if your potting mix and container drain well. “My biggest concern is that I may lose the media through the drainage holes,” says Reiners. “I will often use a sheet of newspaper at the bottom and forgo any additional sand or gravel or anything on top of the paper. In this way, I can maximize the volume of the media that holds both water and nutrients. With the pot shards and pebbles, I lose that precious volume. Maybe not a lot but to some degree.”
David Reed, a horticulture professor at Texas A&M, says that the academic consensus is that drainage layers are counterproductive but that the truth may be more complicated. “Bottom line, I do not know the definitive answer.” But Reed says, “It is OK to put something in the bottom of the pot to prevent the soil or growing medium from clogging up the holes.”
5. Find the ideal spot(s) for your pot.
If you’re gardening on your balcony, in a window box, or from a hanging basket on a porch, finding the best spot will probably mean finding the most sun exposure. Some roses can tolerate some shade, but most will need full sun to produce the best flushes of flowers and disease-free foliage.
Of course, one of the biggest draws of container-grown roses is that they don’t need to be committed to a single site, and can be shuffled around depending on when they’re in bloom. Wang, the expert on Chinese roses, says they were held in such special esteem in ancient China that growers moved them indoors when they were in flower, in the “living room, study, tea room, and so on.”
If your rose is fragrant enough to scent a room, the best place for it when it’s in bloom may be in your bedroom at night, where you can appreciate its soothing fragrance the most. During the day it’s better off outside in full sun. Make sure you protect your floors with a saucer, cachepot, or even a Christmas tree stand whenever you bring a potted rose indoors.
The mobility of containers trumps a permanent garden spot in another way: during the longest, hottest days of the year, roses often go semi-dormant. Or if they continue to bloom the flowers may be a faded version of their spring and fall selves. But potted roses can be moved to a cooler location with less sun and watered more frequently, giving you much higher quality blooms, with better color, form, and fragrance than roses in the garden.
6. Feed your roses.
As with potting mixes, it seems like everyone has a different philosophy about feeding roses in pots. But rosarians almost universally agree that it needs to be done. Lowery recommends that you do it organically by placing a heavy layer of mulch and compost in your pots each year. This way you control garden weeds, supply a constant source of slowly-released nutrition, limit evaporation after you water, and build healthy soil.
It’s only when he neglects slow, organic processes that he reaches for the quick fix of chemical fertilizers. “Sometimes I get lazy…then I find I'm forced to use fertilizers,” he says, noting that a general slow-release fertilizer isn't enough. "Calcium is used up in about a year and can be added easily via CalMag, but that formulation isn’t available in a dry form, or in another form that is immediately usable,” he adds.
If you end up using a fertilizer, carefully follow the instructions on the package. As with watering, there's a delicate balance between not enough and too much.
7. Keep garden weeds and other plants out.
If you haven’t heard about putting companion plants in the same pots as your roses, you will. Be wary when you hear the cheery expression “thriller, filler, spiller” because it may wind up being a killer.
“I’ve had roses die from that,” says Lowery. “One Veronica groundcover overtook a four-year-old rose. At the end of the season, because I had not dealt with it, the rose died. The groundcover had taken up all of the root space.”
Lowery recommends growing complimentary plants in their own pots and arranging them around your rose instead as a “garden of pots.”
Garden weeds can also quickly sneak up on you and steal root space, water, and nutrients from your rose. Pull them as soon as you see them. A heavy layer of mulch helps prevent them.
8. Deadhead and prune.
Most repeat-blooming roses flower more often when they’re deadheaded regularly with the exception of some self-cleaning landscape roses like the Kolorscape series. That means clipping or twisting off the flower stem after a flower is done. This should be done on an ongoing basis during the growing season.
Pruning the whole rose bush at least once annually is also a good idea. More often if you’re growing a larger rose in a pot. Since the roots are corseted into a smaller space than they’d like, the top growth can get too big for them to support. If you don’t keep the top tailored to the root and pot size, the plant will get stressed and you’ll have dieback to prune out anyway.
9. Control pests and disease.
One of the pros of growing roses in pots is that you can protect them from deer, groundhogs, and Japanese beetles. The downside is that roses in pots can be ravaged much more quickly by the pests that do get to them as well as by disease. And they’ll take longer to recover.
Prevent disease by growing healthy roses in full sun. Avoid watering them overhead if possible. Keep them from growing congested by pruning them. You don’t need chemical sprays, but if you do use them, be conservative with them. If they’re unhealthy and unpleasant when used in your garden, they’re much more so when used on roses on your patio or in your home where you would be exposed to them continuously in areas without adequate ventilation.
Pay special attention to stem borers. Their larvae burrow into stems, causing them to die back. If you see little green worm-like creatures on fresh growth, flick them off as soon as you see them. If you see branches with hollow ends, cut them back until you get past stem borer cavities.
10. Repot and root prune.
After two or three years in a pot, most roses will start to decline. If you’re just holding them in a container until you can plant them in the ground, that may be OK. If you plan to grow them in pots indefinitely, you’ll need to repot them by pulling them out of the pot, removing some of the soil, pruning the roots so that they fit neatly in the pot without roping around themselves, and placing the rose back in the pot with new soil. You’ll also need to prune the top so that the roots and the branches are in proportion.
The ideal time to root prune is when the rose is dormant in winter. Doing it during the growing season, especially the heat of summer could be very stressful and fatal to the plant. There are a few other challenges with pruning and repotting roses.
“The moment you get into the business of root pruning...galls are almost an inevitability the longer you keep a rose in a pot,” says Lowery. “Once a particular plant is infected by gall, any piece you take off that plant to root a new plant of it may have that bacteria in it already.”
Lowery says “if you were extremely fastidious in cleansing everything—cleansing your pruners beforehand and then drenching the cuts with a product that prevents that bacteria from invading” you can minimize the risk of galls.
11. Protect in winter.
Quest-Ritson ranks winter protection among the biggest challenges with growing roses in pots because “the roots freeze at temperatures where they would be safe in the ground.”
This is both a problem and an opportunity. Providing adequate winter protection is an added chore that’s far from foolproof and may be impossible in some cases. But if you don’t mind doing it and you’re successful, pots allow you to grow roses that wouldn’t normally survive in your Hardiness Zone. For example, if you live in Zone 4, the only affordable way you can grow most roses for more than a summer is in a pot with winter protection.
When you pick a rose, read the nursery tag to see what Zones it’s hardy to. If, for example, you’re in Zone 8 and your rose is hardy to Zone 4, you don’t need to worry. You might still want to keep it out of heavy winter winds.
If you live in Zone 7 and your rose is hardy to Zone 7—or even if it’s hardy to Zone 6 or 5—consider winter protection, such as placing the pot against the side of a building or wall. You may prefer to keep your potted rose dormant in an unheated garage, shed, cellar, or sunroom. There are a few semi-evergreen roses with shade tolerance that might do OK in your sunniest window during winter.
