Planting Roses in our Desert Climate
By Hal Reynolds, Vice-President Desert Rose Society, ARS Consulting Rosarian
Before we get into the nitty gritty of actually putting roses in the ground, we should cover a few points about where to plant. Roses must have sunshine, at least six hours a day of direct sun. Yes, they will need that much or more sun, even here in our sunny climate. There are a few roses that can survive with some shade but they seldom reach their full potential. It is a good idea to not back your roses up against a wall where they will get reflected sunlight and direct sunlight, thus doubling their potential for burning. Hybrid teas and other large growing varieties should be planted about four feet apart. Smaller types of rose plants can be planted closer. I would point out that I do not give my roses that much space. I grow them closer together than I am telling you. When they are closer, it is harder to get between them for maintenance. The advantage of having them closer is that they help protect each other from our intense heat. Do not plant roses within twelve feet of a tree as the rose will have to compete with the tree for water and nutrients. The tree can block the sunlight and even palm trees, though they do not directly shade a rose, compete for water and food. The roots of some trees (including certain varieties of palm trees) are so pervasive that they can easily choke the life out of a rose bush. In a battle for existence between a tree and a rose bush, the tree will win. After all, the tree is the big bully on that block. I must tell you that this is the voice of experience speaking.
Planting a Bare Root Rose
Planting of bare root roses in the ground in our climate requires specific methods to ensure the success of your plant. Early January is the best time to plant bare root roses here in the Coachella Valley. When ordering your roses, schedule them, if possible, to arrive in early January. When the roses arrive, open them immediately and submerge them completely in a container of water for at least twenty-four hours and up to three days before planting. You do this to rehydrate the plants. The roots must be kept moist until the moment they are planted. Some rose growers advocate adding a few drops of bleach and/or Superthrive to the water. Dry roots equal a dead rose. While the plants are soaking, it is a good time to take them out of the water one at a time to do some trimming. Trim off any broken roots and trim the canes by cutting to an outside bud. Remove any broken or crossing canes. Remember, you are going to have to cover the entire top of the plant with mulch after it is planted.
If you are planting a large type of rose plant, such as a hybrid tea, floribunda, shrub, or climber (or any rose that becomes a large plant), you will need to dig a hole about twenty inches wide and at least fifteen inches deep. When planting a smaller type of rose plant such as a miniature or miniflora, the hole can be somewhat smaller. Remember that you always want to dig a fifty dollar hole for a fifteen dollar plant. No rose will object to having plenty of root space in which to grow.
Our desert soil contains virtually no organic matter and is usually either blown-in sand or a mix of sand and gravel that has washed down from the mountains. There have been virtually no plants living and dying here over the centuries to provide any amount of organic matter in the desert soil. Any organic material the rose will ever have to live in will have to be supplied by you. I usually purchase an outdoor potting soil high in forest humus and peat moss. I take that potting soil and mix it about half and half with some of the existing soil from the planting hole. Mix two or three generous handfuls of superphosphate into the combined soils and mix well.
I then place some of my mix in the bottom of the hole under where the plant will be and then add enough to make a cone shaped mound in the bottom of the hole. The mound should be high enough that when the rose sits on the cone the graft or bud union of the rose will be a couple of inches above soil surface. You can determine proper height by placing a stick or your shovel handle across your planting hole to determine where the soil level will meet your plant. The roots of a bare root rose will fit directly down over the cone of soil mix. The roots should be spread around the cone of soil. Then fill the hole with your soil mix until half full. Water the plant and soil to settle the soil around the roots. Finish filling the hole with your soil mix and water again thoroughly. Complete the planting by forming a mounded ring of soil about two inches high around the planting hole to hold water and direct it down to the roots of your newly planted rose.
Once the plant is in the ground, the entire plant should be covered with mulch. The mulch over the canes helps to protect the bare canes from damage from both wind and sun (it keeps them from drying out) and the mulch also slows down the growth of the buds on the canes. The purpose of this is to slow the buds down, so the roots have a chance to develop enough that they can support the buds when they begin to grow. If not covered in mulch, the buds on the canes will sprout before the roots are able to support that new growth. The sprouts will grow and suck all the life out of the canes and roots and your plant will die.
In only a few weeks, you will see little white buds begin to poke through the mulch. At this time, you can carefully dust the mulch away from the plant or spray it off with a garden hose, being careful to not brush or spray too hard. Once your roses have about an inch or two of new growth on those new buds, you may begin to fertilize them.
Planting a Rose from a Container into the Ground
Planting a rose from a container into the ground can be done almost any time of year. If you are careful in how you handle the root ball, it is really only a matter of substituting the ground for the pot it has been growing in. Check to be sure the rose has been growing in its container for a long enough time that it has developed roots enough to hold the root ball together when you remove the plant from the container. The planting hole requirements and soil preparation are the same as for planting a bare root plant. I take the new containerized plant to the planting hole and tip the container on its side on the ground. I put my foot on the container, press down lightly, and roll the pot back and forth. This loosens the soil from the pot and you can then slip the root ball out of the container.
Carefully lift the root ball by holding the root ball and lower it into the partially filled planting hole. Do not lift by the canes since the root ball might disintegrate, causing damage and stress to your plant. Check to be sure that the plant is sitting high enough that the bud union on a grafted plant is one or two inches above the soil level (own root roses should be planted at approximately the same level at which it was growing in the pot.) Fill the hole half way with your soil mix and water. Then finish filling the hole and water again. Form a ring of mounded soil around the edge of the planting hole to hold water and direct the water to your plant’s roots.
Planting Roses in Containers
First, a few words about containers. Growing roses in containers has some advantages over growing in the ground. In containers you have very good control of how much water and fertilizer each plant is getting. A rose growing in a container can be moved anywhere in the yard to take advantage of any location that suits the individual plant. A disadvantage of container growing is that the bigger plants do not reach their maximum potential size. Large roses will need a fifteen gallon container or larger. I do not go above the fifteen gallon size because containers bigger than fifteen gallon are simply too heavy for me to handle. I put miniature roses in containers about seven or eight gallons in size. Your containers should have adequate size drainage holes because roses do not like to have their roots standing in water. When planting roses in containers, I use pure outdoor potting mix with good forest compost and peat moss content and a handful or two of superphosphate. The reason I use the potting mix alone is because mixing it with yard soil make the resulting container too heavy to handle.
I prefer to use a round tapered pot for planting. In a few years the amount of soil in the pot will decrease as the organic matter subsides and you will need to pull the plant out and replenish the soil. When you replenish the soil in the bottom of the pot and put the root ball on the new soil, the root ball will be smaller in diameter than the top of the pot and that space allows you to replenish the soil around the root ball as well. A straight up and down pot would have no space around the old root ball.
When planting a bare root rose in a container, you use the same methods you do when planting in the ground. Put soil in the pot and form a mound, fill half way, water in, fill the rest of the way, and water again, leaving an inch or two of the pot above the soil level. When moving a plant from one container to a larger container, tip the container on its side, press down on the sides, and roll the container back and forth to loosen the root ball. Then carefully slip the plant out of the old pot. Check the condition of the roots and look for roots that are growing in a circle around the pot. If they are, the plant has become root bound. If this is the case, make a few cuts an inch or so into the soil and through the outside roots and work them loose with your fingers. You are now ready to move your plant to its new home. Partially fill the new pot with soil, set your rose in the center, fill soil around the plant, and then water. Don’t forget the superphosphate. I find that in our hot climate the organic mixture in the pots gets consumed rather rapidly and potted roses must have their soil replenished every year or two.
Planting roses in the desert requires an extra step or two, but if you include those steps, you will have greater success. When considering the overall cost and the work it takes to plant roses, it is silly to take shortcuts. Roses are wonderful plants to grow in our desert climate as they do not get many of the diseases and fungal problems rose growers have to contend with in other parts of the country. Planted correctly and tended with love, a rose will provide you with years and years of delight and beauty.