Growing roses in containers
Container roses are a great solution for gardeners short on space or those who want the freedom to move their roses around. They give you the option of having roses wherever you want them – especially if you are trying to cover up that ‘unsightly spot’ or just want the perfume of roses near your front gate.
Container gardening isn’t just for those short on space – you can bring the garden closer to your living space by adding roses to a patio or even create an outdoor dining area, an alcove, or even line a front walkway. All that is required is ample sun, preferably large pots, and your growing location. It’s a lot easier than growing veggies . . .
With the exception of large climbers, most roses can be grown successfully in containers, but it’s important that the container be large enough to handle the roots for 3 years or more.
Another key is to have good drainage out of the pot, good quality soil each year and a location with 6 hours of light and steady air circulation.
Depending on the size of your container, most roses won’t be a problem, but double check that the individual roses are recommended for your unique climate conditions. In the US, I generally use the Help Me Find search engine. In Europe, I like the GardeniaNet rose reference pages.
7 things you need to know
Beautiful and healthy roses grown in attractive containers can be a beautiful addition to most landscapes. However, a number of considerations arise when growing woody perennials such as roses, in pots. Here are the top 7 criteria for living with these special beauties.
1. Plan on large container sizes
Most roses grow well in containers as long as root space is sufficient and care is appropriate.
Clay containers of at least 2 to 2.5 feet in depth and at least 15 to 20 inches in diameter are recommended for full-sized rose bushes, and generally the deeper the better for rose health, growth, and blooming.
Roses planted in pots and containers generally do not grow as large as those planted in the ground; 4-to-6-feet-tall plants may be the maximum reasonable size range for roses in all but the largest containers. You can beat that limitation by cutting out the center of the pot base, so the roots can spread out into the loosened ground soils below the gravel or bark mulch. If it sits on pavers, just break and remove some, then loosen 8 inches of dirt – that’ll be your personal design secret for healthier roses.
2. Rose Location
Container roses should be placed in a location receiving a minimum of 6 hours of sun just like any other rose. As a result all potted roses need more water than normal. Clay pots will help to keep rose roots cool during hot summers, but clay and terra cotta tend to wick moisture from soil and therefore require more watering than their plastic counterparts. Dark-colored or black plastic pots tend to heat up and stress rose roots during hot weather in most zones. Because of this, I avoid clay 5 gallon pots and all the plastic ones.
3. Planting Method
When planting roses in containers, be sure that sufficient soil is added to completely cover roots to the root crown. Mound soil slightly and monitor over the next few weeks and months to make sure that soil levels do not settle sufficiently to expose roots. Winter mulch is also a good idea.
If you add a rose tree, use a steel or wood pole for support against the wind or an excited animal. Under Northwest conditions, especially near river valleys or Puget Sound, wire guides may be needed.
If you know that the pot will stay in one location, consider cutting out the center of the pot base so the roots can find native soil and spread out. You may have to cut and remove some pavers, but the health of the bush will improve considerably. This is common in southern Europe.
4. Nutrient Needs
Roses are heavy feeders and container roses may need monthly applications of nitrogen, amendments and fertilizers, rather than a longer schedule used for their in-ground counterparts.
This could include foliar fertilization during the blooming season for a commercial or show installation like this downtown sidewalk stunner. A simple 20-20-20 soluble blend sprayed on the leaves early in the day will put fertilizer right where the blooming occurs.
Liquid fish-fertilizers work well for a root zone boost during the blooming season, but a rich soil delivers most of the nutrition month-after-month.
And water. It is critical for pot-bound roses. The cylindrical pot exposes the root system to a lot more heat than a ground-planted bush. Water gently to soaking 2 times at each watering for a thorough saturation of the soil. It may be daily during hot summer weather.
Automated watering systems are a good idea – and are essential in a commercial application, as shown here.
5. Rose Varieties.
Miniature roses are particularly well-suited to containers. As always, be careful when making your selections: miniature roses often come in small pots and have small leaves and flowers, but this can be misleading as an indication of eventual plant size.
Mini roses may grow to over 3 feet in height and become too large for the space or container originally selected. Also, when planting minis, keep in mind the proportions of the bush to the container, as shown here. The bush should dominate the image, not the pot.
Miniflora roses are larger than miniatures and are bred specifically for rose shows. They tend to have ungainly structures that don’t work well in containers, or in most garden settings.
Resist the temptation to purchase for garden use the cute or inspiringly lovely potted miniature roses you might see in the grocery store checkout line that are greenhouse-grown. These are usually not suitable for your climate and outdoor growing conditions.
Purchase known rose varieties that are suitable for your zone from a reputable nursery or mail order source. Good staff members can guide you when you explain that the bushes are for large pots, rather than in-ground.
Hybrid tea roses can work really well if the pot is a 3 1/2- 5 foot tall one. Pot-to-plant proportions can be very attractive – plus there are thousands of colorful varieties to choose from.
Large rose varieties, including many climbers and shrub roses, generally don’t perform well in containers but may perform reasonably well in large containers or planters of 2 1/2 – 4 feet deep if they’re trimmed well each year and are securely attached to structure. A fallen over climber is a day-long project to repair, re-trim, and clean up after. Nobody wants to be “that guy”.
6. Add some rose companions
Roses in containers will generally be grown most successfully when they aren’t competing with too many other plants for root space at the same depth.
While attractive groupings of roses, perennials and annuals are possible, be judicious about crowding roses in containers. All the plants will share insects and diseases like fungus.
Possible companions for container roses include alyssums, low-growing annuals, or small, well-behaved ornamental grasses, especially in colors that compliment or contrast with your specific rose bloom colors as shown here.
Here are 5 inevitable things you need to manage on a yearly basis if you plant roses in pots.
A. Root binding
It is inevitable with most potted roses that roots will outgrow the available soil and space. Root binding will cause many roses, and particularly those in pots less than 3 ft tall, to decline within a few to several years as the roots circle, exhaust available nutrients, and become so densely packed inside pots that water and nutrients may not penetrate at an effective rate.
Root binding is a common cause of stress, disease, pest infestation, and death in potted roses. To keep roses alive and healthy indefinitely in pots, they are usually moved to a larger pot with fresh soil about every 3 years. During this cycle, it is a good time to double check that the pot is sitting on 3 small feet above the ground level and add an automated watering system to the pots.
I prefer to carefully root prune during a time of year when the plants are dormant and not blooming, and when weather is below 60 degrees, then return them to the same pot with fresh, nutrient-rich soil. To me this is less of a cost and labor headache than up-sizing large pots – but I use 3 1/2 ft tall pots . .
B. Soil dryness
Soil in pots tends to dry quickly, and roses in containers usually need much more frequent watering than those planted directly in the ground. Watch for rose leaves curling inward or wilting slightly and be diligent in avoiding significant wilting.
Container roses may need daily watering during warm weather, and in some cases even twice a day during heat waves, particularly in 5 gallon pots. This was mandatory when I ran retail garden centers. This is where cut-bottom pots are worth the effort, so that roots are connected into the larger soil ecosystem in the soil below where more water is available.
C. Nutrient exhaustion
The limited volume of soil in pots becomes exhausted and leached over the blooming months each year. Maintain surface dressing of compost and amendments under mulch for all blooming roses, and consider using slow-release organic fertilizers if your potted perennials show nutrient deficiencies.
Correct watering is imperative, since it will break down the soil nutrition enough so the roots can take it up into the canes where it needs it. Remove the old thin soil and replace it with denser, richer new soil for the following blooming season. This is a perfect time to add an automated watering system too.
D. Salt burn
Minerals are added to most municipal water to prevent corrosion and extend the life of water pipes. When potted trees and plants use city water, such as that coming in through house faucets, some of the water evaporates, which leaves minerals behind as shown here. Usually these salts in the potted soil tend to build up over 3 seasons and can sometimes become toxic to your weaker rose plants.
Damage from this typically appears as dead, brown leaf edges on the rose leaf, which may extend to most or all of a leaf’s surface. If allowed to persist and worsen, this will eventually kill almost any potted rose plant or rose tree.
To address salt burn, soil in pots must be flushed periodically to dissolve and remove mineral build-up. This can be accomplished by making sure a potted plant stays outdoors all day in rain for a few days per month.
Roses grown in pots under porches or in areas unwatered by natural rainfall generally need to be flushed at least twice per year.
E. Anaerobic soil
All rose pots should have large holes in the bottoms to allow for complete drainage. Water can become trapped in pots with no rocks or gravel – creating poor drainage. Once oxygen in the water is depleted, anaerobic organisms multiply and produce foul-smelling byproducts that are toxic to your plants.
This may occur in pots or sometimes beneath the soil surface in poorly drained landscapes. Drainage may be improved and therefore anaerobic conditions reduced by a complete removal of the bush and bad soil in cool weather. After a thorough clean of the pot and the drain holes, restart the planting by including smooth rocks and loose gravel in the bottom of containers, especially in deep containers before adding the soil.
Limited space? Adding a patio feature? Now you know how . .
You can still enjoy the beauty of rose color and texture by growing them in patio containers. All types of roses can be grown in containers – it’s very simple provided you follow a few simple guidelines.
On the small side: miniature roses are especially well-suited for containers because of their dwarf habit and fibrous root system.
On the tall side: climbers provide an added bonus when pot-grown because they can be grown straight up a pillar or trellis using minimal floor space while adding tall color to the garden.
I believe it’s possible to grow any type of rose in a pot as long as you provide it with a few sensible requirements.
Anyone that tries to tell you that a rose is not suitable for container growing just hasn’t found the right container yet!
Try this next year, it might change everything: the new roses will start arriving in early February . . .