Container grown roses can be just as satisfying as roses grown in the ground and for those with limited space or those whose rose collections are growing faster than their planting beds, it can be a necessity. Here, I will address container choices, the size containers roses need, and the basics of growing roses in containers.
Garden containers for roses choices range from the black plastic pots that nursery plants are usually sold in, to the elaborately painted ceramic pots that can be bought in upscale home stores. Which containers are appropriate for growing roses? Well, most are.
My Jeep Cherokee was a lot less expensive than the Jeep Grand Cherokee, so does that make my Cherokee less useful to me? No, it gets me to all the garden centers and I can fit just as many plants in it as I could a Grand Cherokee. It just isn’t as pretty nor does it have as good a stereo system as the Grand Cherokee. The point is, is one type of container a better choice than another? It depends on your needs and budget. Plastic, usually black, is the standard.
The first item to consider when buying a container to grow a rose in is whether the container has a drainage hole or not. The water needs to drain out of the pot by its own accord. With house plants, I often insert an already potted plant into a decorative pot without a drainage hole. These pots add beauty to my decor and they help keep drainage water from reaching the furniture. The drawback is that the container will need to be brought over to the sink to drain the excess water out. Try dumping the water out of a decorative container with a rose in a five gallon pot inside it, even just by tipping it over! I wouldn’t bother doing it too many times myself as the container would just be too heavy. And if the water is not dumped out, then the rose could die of root rot. So, if the container doesn’t have a drainage hole, make a hole. Plastic pots are easy enough to poke holes through with a sharp object. With terra cotta or concrete containers use a drill with a masonry bit. I personally still wouldn’t drill through an expensive ceramic pot. If you want to use it in the garden, use it as a sculptural focal point and forget the plant.
Types of Pots
Plastic pots hold water well and they are inexpensive so if they split or the rose outgrows the container they are easy to replace. The vast majority of my container roses are in black plastic pots. One negative to black plastic is that they absorb heat, thus the soil and the rose’s roots can get too hot. Also, plastic disintegrates over time, so pots will eventually have to be replaced, though for me, this has not been much of a problem.
There are two ways to address the over heating of the plastic pot.
First, group the pots or place them near something that will shade the pots themselves without shading the roses. I keep my pots between raised beds of roses or in amongst other plants.
Second, place a couple of inches of mulch on the soil in the pot. The mulch will also help retain water in the container. Synthetic terra cotta or concrete pots also make good containers for roses and have the same water retentive qualities as plastic. Terra cotta and concrete both have the same advantages and disadvantages.
For advantages, they are more decorative than black plastic, they are heavier than plastic so they won’t blow over as easily, and their lighter colors don’t heat up as much as the black plastic. As to disadvantages, water moves right through the sides of them to evaporate, thus the soil dries out quicker and they are usually susceptible to cracking in freezing temperatures (especially the inexpensive ones like those from Mexico). These container’s greater weight makes it a hassle to move them to a protected area during freezing weather. If these containers do blow over on a hard surface such as a concrete pool deck, they can break, I know. The evaporation of water through the sides can be stopped if the pot is painted or sealed.
Peat and pulp pots have become a lot more popular. Unless the plant is going to be planted in the garden in a few months don’t use them because they will break down regardless as to whether they have been buried in the ground or not. Also, I find that roses in these pots dry out faster and use up nutrients faster than roses in other types of containers.
I just love it when my door bell rings and I open the door to find a box of miniature roses left on the stoop. I open the box and inside the roses are in four inch pots delicately wrapped in newspaper. Do I leave them in those containers for long? No, I allow them a few days to acclimatize and then I repot them into a one gallon pot. After a couple of months, assuming that they continue to grow well, I move them to a five gallon container.
When I receive large bare root roses, I plant them into five gallon containers and grow them there at least until the fall and often for a year or more. For me, the five gallon black plastic container is the standard. If you are unsure what a five gallon container is, go to a local nursery and ask them to show you a five gallon shrub.
While I find the five gallon container the most useful, roses can be grown in other size containers as well. If the rose is a hybrid tea or small shrub rose, it would probably be better off in a ten gallon container. Also, half barrels and 15 gallon containers can be used but they are heavy, so don’t plan on moving them unless you keep them on wheels. I don’t personally know any one that uses them as a staple.
The size of the container does limit the size of the rose you can grow. Trying to grow large growing roses like Queen Elizabeth or Sally Holmes is going to be more difficult and most likely less satisfying. There are smaller growing varieties of almost every type of rose. For those who don’t have room for even five gallon containers there are micro minis which will do well in just three gallon containers.
The primary consideration for growing roses in containers is the amount of water they need. To determine if your roses are receiving enough water, stick your finger in the soil each day and see if the soil is dry just under the surface. I have to water my roses once a day during the summer in 90 degree temperatures and when the temperatures soar over 100 degrees I have to water twice a day. Even during our cold, 20-40 degree winters (I can joke about these things now that I am in Texas, as I grew up in New Hampshire and I lived eleven years in Minnesota) I usually have to water once or twice a week. In fact, if a cold spell is coming I make sure that I get out and water my containers as dry plants are more susceptible to freezing.
On the subject of cold weather, plants in containers are more susceptible to freezing than plants in the ground, usually it is equivalent to being one zone colder, so container plants will require extra protection. If the temperatures are going to drop below twenty degrees in my zone7b garden, I put the containers into the garage. In colder areas of the country, it would be best to plant the rose still in its container into the ground for the winter and mulch the top as you would your other roses. For those in zone 4, dig a trench and throw the plant in (in late fall season I always found it too cold and dark to place things gently), container and all.
Fertilizing is also a little trickier with container roses. I fertilize them approximately every two weeks with the amount of fertilizer as recommended on the package, for containers. Container grown roses can be fertilized more frequently than that with more diluted amounts of fertilizer. Most types of fertilizers will work including: water soluble fertilizers, fish emulsion, alfalfa meal, or alfalfa tea. Fertilize miniature roses lighter or just with organic materials or there may be too much vegetative growth at the expense of flowering. Also, slow-release container formulated fertilizers like Osmocote® work well. Use them according to directions. Don’t use slow-release lawn fertilizers on container plants — it is too hard to regulate the dosage and your plants might get fertilizer burn. I know this too from personal experience.
I have found that a light soil mix including peat for water retention and perlite for better drainage, ideal for growing roses.
What to do with all these container roses? Design a special area for them, place them decoratively on your patio maybe with smaller flowering annuals in containers at their feet, or scatter the pots through out an existing garden to add height and more color to your garden. Enjoy!
By: Carolyn Hayward, drawyah[at]onramp[dot]net