San Diego soil tends to be poor for growing roses. Either the soil is too heavy and drains poorly (a typical clay soil). Or the soil might be too sandy or have too much decomposed granite to hold the nutrients necessary for growing great roses. If you want to grow roses and you have poor soil, you have 3 choices for fixing the problem.
You can overhaul the soil and give it the good drainage and nutrients needed for roses. In March I talked about how to fix poor soil so check on those posts for tips on soil. Your second choice would be to build a raised bed with retaining wall materials. A raised bed that is at least 12 inches tall will allow you to plant the roses in good quality soil that you bring in.
The third choice is to use containers for the roses. Plastic pots like the ones seen in the photos are great for putting together a rose garden in tricky areas like patios or gardens with rock hard soil. Another advantage to container rose gardening is that you don’t have to bend down so far to prune the rose. All of my roses are in containers and I win over a hundred ribbons, along with a few trophies a year from my collection.
For hybrid tea and grandiflora roses I recommend a 21” diameter plastic pot. A 15” diameter pot will work for the smaller floribunda and miniature roses. The ones in the photos were purchased at Home Depot. Never use a ceramic pot unless it has a glazed interior. The porous surface of ceramic pots will suck water away from the roots. Make sure that the pot has a drainage hole in the bottom and never put the pot in a saucer that will keep the bottom of the pot constantly wet. Roses, like humans, like dry feet.
Use a good potting soil like Super Soil (sold at Home Depot) for the planting mix. Since roses in containers need more water and nutrients than roses planted in the ground, use a slow release rose food like Ada Perry’s Magic Formula to give the rose a steady diet of good food, see my post in February about feeding roses. Also, make sure to have a nice wood chip mulch to keep the soil moist.
One of the advantages of roses in container is that all the water stays close to the rose and does not run off (but it will run out the bottom of the pot). If you live in the inland areas (east of Highway 805) of San Diego like I do, then soak your container roses 3 times a week in the summer. I put enough water on my rose to fill the container about 1 inch. Less water is needed in the coastal regions and during the cooler months. Always water in the morning so that the rose foliage can dry out by evening. This will help prevent diseases like rust and powdery mildew.
Once you have watered your rose, don’t try to move the container without a hand truck. A 21” diameter pot with wet soil can weigh over a hundred pounds. It is always best to move the pots around when they are dry.
One of my favorite aspects to a container rose garden is the fact that I can move the roses around throughout the year depending on what is blooming. This allows for a garden that is always interesting to look at and a little easier to maintain.
Container roses after pruning.
Photo by Doug Kalal