Roses In The Landscape
As Landscape Architects, the plants we incorporate into our designed spaces are as integral to the experience as our built structures. We love many plants for their beauty, durability, and long-term performance in the garden, and of course we share our clients’ favorites, among them the most beloved rose. Throughout recorded history, few plants have received the same attention as the rose, the star of formal gardens and cottage gardens, and a symbol of love and beauty nearly worldwide. But roses have earned a mixed reputation when it comes to ease of growing. If you are new to growing roses or have had challenges in the past, here are some tips to maintain your roses to set them up for success!
Finding the right rose for you is definitely a matter of the heart. But there are a few things to know going in. Roses have been domesticated for so long that there are literally thousands of varieties, with different habits, growth patterns, and needs. So knowing what you are getting will help you get the right rose for your spot. For a helpful guide to roses available in the Bay Area and beyond, see this fantastic list from UC Davis Foundation Plant Services.
Bush (Shrub) Roses
Many of the classic favorites fall into this category. Bush varieties can range from a couple of feet in height to more than 10 feet, so be sure and check the label! In addition, there are differing qualities in these hybrids based on what you want in a rose- will you be cutting them for vases? Or is a long bloom season the most important quality? How about intensity of scent? Deciding these factors can help narrow down your choices just a little.
“Everybody wants a box of chocolates, and a long-stem rose” -Leonard Cohen
If you love to have cut flowers in the house, long-stem roses may be the way to go. These plants have been bred specifically to flower on strong, upright stems. They do tend to be taller and narrower as well, so if you need a plant for a tight spot this may be a good option.
It would be a stretch to classify even the tallest of rose varieties as a real tree, but when you go to a nursery you hear this term tossed around a lot. ‘Tree’ roses come in countless varieties, but have one thing in common- they have been grafted, or attached during their early growth, to a strong upright rose-cane ‘trunk’ on hardy rootstock in order to mimic the shape of a tree. The term ‘Standard’ can also apply to roses and other plants that take on this form. If grafting seems weird, know this- almost all cultivated roses in America have grafted rootstock, even if they are not ‘trees’. This is because a rootstock immune to certain diseases can keep roses healthy in the long-term.
As the name suggests, climbing roses need to do just that. Don’t believe that you can keep them in bush form just by trimming. Climbing roses have got to climb… and they will just keep trying! But is there anything better on a trellis or bower than a spectacular climbing rose?
Again, we state the obvious… these roses cover a lot of ground. A great way to have roses if you don’t have a lot of vertical space, groundcover roses usually range from 1 to 3 feet in height are also popular for hedging and soil retaining on hillsides. Without the same pruning needs as bush roses, they are a low-maintenance solution. Not to mention, they are tough as nails!
The sweet plants from which all roses originate, the wild roses, are a category unto themselves. Like all native plants these roses have specialized to different habitats, so introducing them to the garden means finding a spot similar to what they’re used to in the wild. Wood roses, for example, actually prefer some shade, while nearly every other rose wants full sun. They also tend towards smaller flowers with open centers, but are no less lovely than their fancy cousins. They may be a good option if you do have a shadier yard.
Wild roses and some cultivars also bear spectacular fall fruit! Known as ‘hips’, these can be very showy in the autumn garden or in flower arrangements, and can also be used as an herbal supplement high in Vitamin C!
There’s always that one plant that won’t cooperate, but when it comes to drastically increasing your rose gardening success, there are a few basics that will get you off on the right foot. In general: full sun, regular water, regular rose-specific fertilizer and seasonal pruning make for happy roses and happy gardeners.
Roses have a habit of letting you know pretty quickly if something is wrong. This is great as it gives you the opportunity to help! Plus, they are incredibly responsive to treatment. Here are some classic rose conditions and what they look like. Images link to the UC Integrated Pest Management (IPM) website for easy identification and tips on managing plant diseases and pests.
Black Spot and Rust are the most common fungal conditions that affect roses, and almost any rose can fall victim to fungal disease. Certain environmental conditions are more friendly to fungi, and management of these conditions can prevent the growth and spread of fungi. Avoiding warm and wet conditions is the key to preventing fungal growth, especially avoiding wetting leaves when watering in a warm climate (are your roses getting hit by a lawn sprinkler? This is the classic situation!). Bay Area fog is also infamous for creating prime fungal growth conditions, and this is of course harder to manage. Removing the most-affected leaves and spraying with antifungals will prevent the spread of the disease to other parts of the plant. To protect neighboring roses, removal of fallen leaves and good pruning practices will create a less fungal environment.
Insects of many species love roses, and can cause a lot of damage if allowed to proliferate. Rose Bollworm is a common pest in Mediterranean climates. Its attack of young rosebuds and flowers can have unfortunate results, creating misshapen, hole-filled buds and blooms. A tiny caterpillar rather than the ‘worm’ that the name suggests, this pest is best controlled by hand-picking or a biological spray such as BT. Speak with your local nursery about the safest alternatives.
Mites can also damage buds and have the disadvantage of being so small that they can rarely be seen by the naked eye. Buds that won’t open, strangely crinkled young leaves, and a sticky or ‘dusty’ residue on the plant can indicate a mite infestation. Sooty Mold, or a black residue that can be rubbed off of leaves, is also an indicator and will vanish once the bugs are dealt with. Mites are best controlled with a mineral-oil based spray, regularly applied, until the signs diminish. As with Budworm damage, crinkled buds and leaves will not recover, so they can be removed.
Aphids are the bane of every gardener’s existence, and their damage is similar to that of the mites, however they do have the advantage (to us, at any rate) of being very visible. Clusters of sesame-seed-sized insects are usually aphids, although they vary greatly in color from black to green to nearly see-through. Aphids are best controlled with regular spraying and are best dealt with quickly before their populations get out of hand. A variety of other sucking insects can affect roses, visit this page of the UC IPM website for rose-specific insect identification.
What are systemics?
Systemic insecticides are a family of insecticide that is absorbed through a plant’s roots, rendering the plant poisonous to any insect that may take a taste. Sound great? The one true disadvantage to systemics is that they do kill all insects, even bees and butterflies that pollinate the flowers, and predator insects such as ladybugs and mantises who ingest the poison in the bodies of their prey. The chemicals present in these insecticides may also affect larger animals that feed on insects, and as they are unsafe for human consumption would be unadvisable for roses used in tea or cooking. We don’t advise for or against garden chemical use, but feel it is important for all gardeners to know the risks. If possible to control pests by other means, we encourage more sustainable practices for the good of all.
Pruning is an art form with many schools of thought. We can offer the basics as far as roses go, and encourage you to read further if you’d like. The primary goals of pruning are to increase air flow and light accessibility to all parts of the plant, to maintain ideal size and shape, and to remove any damaged areas. Roses are vigorous plants and benefit from hard yearly pruning during the dormant season. In warm winter climates where they do not lose all of their leaves, late fall is usually a good time to prune provided the weather is not overly wet. Opening up the center of a rosebush and pruning to an outward-facing bud is the best way to maximize flowering for a bush or standard rose. For step-by-step pruning, we like this guide from Fine Gardening Magazine. Be sure to prune above the graft (usually a visible nub at the base of the plant- see photo below), or your roses may become a surprise new variety next year!
Groundcover roses can be given a good chopping back to 6” above the graft, with any unsightly or tangled branches removed. Climbing roses benefit greatly from pruning, but their tendency to intertwine with structures makes this a more difficult task. In general, pruning back to within a couple inches of the main canes is a good way to go. Follow this guide for more specifics. If a rose is climbing vertically, prune to an upward-facing bud to encourage good growth habit. If canes begin to get woody or die, they can be removed entirely. But if they are impossible to remove due to the structure they are climbing, forget it. They will soon be covered again with a great show of foliage and flowers.
We hope this guide is helpful to anyone growing roses in their landscape this year or next! Have no fear when it comes to planting these beauties – the rewards are always great for the work you put in maintaining them. For more gardening advice and design inspiration, check this blog weekly. For garden consultation or to learn more about our landscape design and architecture services, contact our studio. We look forward to hearing from you!
The J. Montgomery Team