A Comprehensive Guide to Growing Roses in Zone 9
Are you a Zone 9 gardener who wants to embark upon rose cultivation? Good news! Roses grow happily in this climate. Follow along as gardening expert Melissa Strauss walks through the proper care of roses in Zone 9 gardens.
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Roses have a reputation for being high maintenance. I would love to tell you that this is an undeserved reputation. However, in some climates, they are indeed, are tricky to cultivate. If you are a Zone 9 gardener, though, I have great news for you. These beloved garden bloomers are well suited to warm climates, and there are very few that don’t thrive in Zone 9.
Now, just because most roses will grow in this zone doesn’t mean that you can just plant them and forget them. Most garden roses are not native to the United States, so they need some extra care and consideration. For those of us lucky to be gardening in Zone 9, these considerations are fairly minimal.
With a bit of planning and preparation and a moderate level of upkeep, you can get off on the right foot. Let’s take a look at some of your rose options. Then, we can talk about steps that will help you to maintain a healthy plant for many years.
Choose the Right Type
There are very few roses that won’t grow in Zone 9. They are a staple in many Zone 9 gardens, as the long growing season is conducive to repeat blooming. The salinity of your soil can be a concern, particularly in coastal areas. However, for the most part, Zone 9 is a great climate for growing roses of all types.
Since nearly all varieties will grow in this Zone, the sky is the limit. It’s really a matter of personal preference. Let’s go over common types and their characteristics.
Old Garden Roses
Old garden roses are any variety that predates 1867 when the first hybrid tea came onto the scene. These roses of antiquity tend to be hardier and more resistant to pests and diseases than hybrids.
They are not as picky about soil and typically have large, fragrant flowers. Because they only bloom once per year, old garden roses are sometimes passed over. However, their large, intricate, fragrant flowers are unparalleled in the flower world.
Hybrid Teas
If you are looking for a rose that belongs in your cutting garden, hybrid tea roses are the way to go. Their breeding emphasized particular traits that make them excellent cut flowers.
Long stems and large, shapely blooms are defining characteristics. The plants have an upright growth habit, and they are repeat bloomers. Some of them are fragrant, but usually not as strongly scented as their ancestors.
Knockouts
Knockout roses are ideal for novice gardeners. They are a relatively new type, with excellent disease resistance. They tolerate a wide range of temperature and climate conditions and are very reliable bloomers.
This is a repeat-blooming shrub that requires less maintenance than most other types. These roses are not usually fragrant, and they don’t last as long as cut flowers. If those qualities are important to you, consider a different type.
Floribundas
Floribundas are a hybrid cross between tea roses and polyantha roses. They tend to be fragrant and very big bloomers that produce clusters of medium-sized flowers. The plants are lower growing, with more of a sprawling habit than hybrid teas.
This makes them an attractive landscape element. Their flower clusters are good for cutting. These are repeat bloomers that will produce flowers from late spring until early fall.
Grandifloras
Grandiflora roses are a product of breeding a floribunda back with a hybrid tea to increase the best attributes of each. These tend to be a favorite among florists for their large, fragrant blooms on slender stems.
They bloom repeatedly, an attribute inherited from their floribunda parents. These are large shrubs that make a major statement in the garden.
Climbers
Climbing roses come from many groups and have a growth habit that is more trailing than climbing. Still, you can train them to climb or ramble, depending on your garden needs. Some are fragrant, while others are not.
Many are thornless or nearly so. These tend to bloom big in the spring and then sporadically in the summer or fall. They aren’t the best for cutting, but they make a major impact in the garden.
Planting
How you plant and care for your flowering shrub is sometimes more important than your climate. Roses have a reputation for being fussy, but if you plant them in the right space and meet their needs, they are no more difficult than most plants.
They are heavy feeders, so amending your soil with compost or manure will give them a healthy start. Add some bone meal for an extra boost at planting time. The ideal time to plant in Zone 9 is in the spring. The earlier, the better. The beginning of fall is another time, as long as there is at least two months of frost-free weather.
When choosing a spot to plant, sun exposure is an important factor. In most climates, roses prefer full sun, the more the better. However, Zone 9 summers can be intense and hot. Some shade in the afternoon is ideal in this climate, as it will give your plant a break from the heat. Just make sure that your location gets at least six hours of sun, or you will miss out on some blooming power of your plant.
When growing in pots, water the plant a few hours before planting. This will help to reduce shock. You can soak the roots of a bare-root rose to achieve the same purpose. Dig a hole that is twice as wide and a few inches deeper than your root ball. For bare-root roses, form a mound of soil in the bottom of the hole and spread the roots over the mound.
If you are planting a grafted rose, the joint should lie just below the surface of the soil to prevent suckers from the rootstock. Otherwise, plant with the top of the root ball level with the surrounding soil. Water it in deeply to encourage deep root growth, and add a layer of mulch to prevent rapid evaporation.
Care
These heat-loving plants thrive in warmer climates. Watering is an important factor in Zone 9, as the heat will cause the soil to dry out faster. Gardening in Zone 9 does eliminate some of the concerns that you would face in climates with cold winters.
Water
Zone 9 roses are likely to require some extra watering. Your new plant needs moist soil to establish roots. Water every day for the first four weeks. Then, water every other day for the next six months. If you get plenty of rain, factor that into your watering routine. You don’t want soggy soil, as that can cause root rot.
By the same token, you want to water deeply to encourage deep-root establishment. After about six months, you can reduce your watering to about once per week. Once the plant has roots established, the general rule is to water deeply but infrequently. During the hottest months and in times of prolonged drought, provide some extra water.
Fertilizer
Roses are heavy feeders and need fertilizer on a regular basis. During the growing season, fertilize every two to four weeks, depending on the type of fertilizer. Young plants should get a liquid fertilizer more frequently. Established roses will do well with a slow-release formula applied monthly.
Near the end of summer, an application of bone meal or a low-nitrogen fertilizer will strengthen roots. This will also contribute to stronger flowers the following year. Stop fertilizing at least a month to six weeks before the first expected frost. New growth is more susceptible to damage, so you want growth to harden before freezing weather.
I realize that Zone 9 doesn’t always experience a hard freeze in the winter, but it can happen. You want your rose to be prepared to withstand that weather if it occurs.
Pruning
You usually don’t need to prune until your rose bush is a couple years old, unless you see dead or damaged canes. In Zone 9, you should prune your rose at the beginning of February. You want to prune before the plant begins to put forth new growth. It is important to note that pruning will encourage buds to begin breaking. If you prune too early, that new growth can be susceptible to a late frost. The ideal time to prune is just as the buds begin to swell.
How to Prune Your Rose
- Make sure that you are using a clean, sharp tool to do your pruning. Clean cuts heal fastest, and this helps to prevent bacteria from entering the cuts.
- Remove any dead or diseased branches until you reach a healthy, white pith.
- Remove any crossing branches that interfere with air circulation to the interior of the plant.
- If this is the first time you are pruning a new rose, prune it hard to encourage branching.
- For established roses, prune off any canes that do not bloom well.
- For upright-growing roses, choose outward-facing buds that are between 1/3 to 1/2 way down the stem. This will create a nicer shape as the bush grows. The new growth will face outward, creating a vase shape. Don’t remove more than 1/2 of a stem.
- If your rose is a spreading type, alternate between inward and outward-facing buds to keep the plant well-balanced.
- Make your cuts no more than 1/4 inch above the bud. Cut at an angle so that water doesn’t collect.
- Remove any suckers at the ground level to avoid the growth of the rootstock.
In addition to your yearly pruning, make sure to deadhead during the blooming season. Deadheading involves removing the spent blooms from the plant. You can do this manually or with hand shears. Deadheading helps the plant to redirect energy toward forming and supporting new blooms. If you’re growing hips, though, skip this step.
Potential Problems
The climate in Zone 9 is conducive to growing large, healthy plants. Roses like heat, so the summers in Zone 9 are not troublesome to most of these plants.
Fungal Diseases
The biggest concern in warm climates, as they tend to be humid, is fungal disease. Conditions such as black spots, powdery mildew, and Cercospera leaf spot can all occur under humid and warm conditions. If your climate is very humid, pruning is important.
Thinning out the interior of your shrub is very helpful in preventing fungal diseases. You can also use a fungicidal spray to treat and prevent any fungal issues. When you water, water the ground at the base of the plant and avoid wetting the foliage.
Pests
There is no shortage of garden pests in Zone 9 gardens, and they can be troublesome for your roses. Aphids are the most common garden pest that you’ll encounter. A strong stream of water from a hose will help to deter and eliminate aphids. Attracting beneficial insects like mantids and ladybugs will help, too. A ladybug’s favorite meal is aphids. Companion plant with alyssum, coreopsis, and yarrow to attract beneficial insects.
Capsaicin spray is another good way to repel harmful insects in the garden. These sprays are available commercially, or you can make your own. This will also deter rabbits and squirrels from snacking on your bushes.
Sunburn
Sunburn on rose canes appears as blackened areas on the canes. It can be the result of too much heat or sunlight reflecting off the side of a building. It can also occur in conjunction with spider mite damage. A plant that is weakened by pest infestation is more susceptible to other types of damage.
Rose Rosette Disease
Also called witches’ broom, rose rosette disease can devastate a plant quickly. It is spread by mites (specifically the species Phyllocoptes fructiphilus) and causes mutated growth. Look out for multiple stems with extra thorns growing in clumps. Distorted and off-color buds fail to open, and red leaves don’t mature to green as they age with this disease. If you notice these symptoms, the only solution is removal of the entire plant, including the root ball. Dispose of the plant to prevent further spread.
The best way to control the spread of this infectious disease is to monitor your plants for symptoms, keep them as healthy as possible (stressed plants are more likely to be attacked by mites), purchase roses from a reputable source, and avoid commonly infected species like multifloras and Knockouts. To lower chances of mites visiting your garden, interplant with companions that attract their natural predators. You can also spray horticultural oils at the beginning of the season in mild temperatures below 85°F (29°C).
Final Thoughts
Roses don’t have to be intimidating, especially in Zone 9 where many types will thrive in warm, sunny weather. Remember to provide plenty of nutrients, and keep up with pruning. Water deeply, and deadhead those spent blooms. Follow these tips, and you will have beautiful blooms for years to come.