Roses can be intimidating, so much so that many gardeners don’t bother, but my guest this week, rosarian Paul Zimmerman, wants you to know that that reputation is not deserved. Paul is an expert on growing roses sustainably, free of chemicals and with little intervention on your part.
Paul was a founding member and president of Tinseltown Rose Society in Los Angeles, and he ran a business there, Hundred Acre Woods Rosescapeing, a company specializing in the care, design and installation of rose gardens. Today Paul is a consulting rosarian and a contributor to Fine Gardening magazine, plus he penned a book, “Everyday Roses: How to Grow Knock Out and Other Easy-Care Garden Roses” by Paul Zimmerman and he lives in the foothills of the Blue Ridge Mountains in South Carolina.
Paul says that you don’t need to smother roses in chemicals and pesticides to have success. He reminds clients, “Roses are plants, too.” When roses are thought of as plants rather than something mythical, it takes the intimidation factor down several notches.
“When it fails to meet that exceptional level, we feel like there’s a failure at some point,” he said. “We need to change that mindset.”
Paul believes that every gardener wants to grow roses. So why don’t we? Paul says gardeners were either given a bad rose that didn’t do well, or they heard that roses were incredibly fussy divas and never got started in the first place.
“There’s an inner rose grower in every gardener, and we just got to unleash it,” he says. Roses, when it comes down to it, are flowering shrubs. “It’s a landscape plant, first and foremost.”
When I got my start in gardening, I was 8 years old and living in Miami — the same city where Paul lived back then. My very first garden was a rose garden, so among all the plants that I love, roses hold a very special place in my heart. Paul and I both remember Shaw’s Nursery in Miami, where I rode my bicycle as a kid to ask for rose growing advice. However, despite their reputation for being difficult, I never found roses all that hard to grow.
To get off to a great start growing roses, you can download my new free resource, Growing Garden Roses: A Quick Guide to Using Sustainable Methods and a Healthy Dose of Common Sense. Armed with the right information, you too can grow beautiful roses in your garden — and grow them sustainably.
How Paul Zimmerman Went from Show Biz to Rose Biz
In his early 30s, Paul was working on stand-up comedy and television production, and he decided that he wanted out. He took a little time to decide what his next stage in life would be. “I started growing roses, and I don’t know why,” he recalls. But as his wife points out to him, when he decides to learn something, he doesn’t just learn it, he goes way over the top.
Two years later, he was the president of a rose society. It didn’t occur to him that he could turn his knowledge into a business until one day he was showing a rose society member how to properly prune roses. A neighbor came by to admire his work and asked what he charges. That’s when it clicked. Fast forward another two years and he had a crew of six workers taking care of 60 rose gardens in Beverly Hills and Bel Air. He had many celebrity clients but, being that he was a show business veteran himself, he was never star-struck.
Los Angeles was a hotbed of chemicals, Paul says. “Everybody was telling me, you’ve got to spray this, you’ve got to spray that.” But that’s not how he was raised, and he was tired of visiting gardens that were insect deserts.
Roses Are Not as Tough to Grow as You Think
Bill DeVor, who runs the rose program at Greenheart Farms in Arroyo Grande, California, did a talk to the American Rose Society about seven or eight years ago in which he said, “We in the industry have spent the last 60 years trying to convince people not to grow the very thing we’ve been trying to sell them.”
Paul says Bill encapsulated it beautifully: the messaging on growing roses is all wrong. It scared people away.
Paul’s approach is to tell gardeners and homeowners that a rose is just a plant. And when they realize it’s just a plant, that reduces the intimidation factor.
Roses don’t really need a spray program and an intensive fertilizer program. And unless you plan on being a rose exhibitor and winning blue ribbons, you don’t need a perfect long-stem rose. In fact, Paul says it was the writings of rose exhibitors that gave roses a reputation for being fussy.
For most of us, growing roses just means having a pretty plant that, for the most part, will bloom from spring to fall and grow from 1 foot high to 30 feet up a tree. And the flowers come in every color of the rainbow, but blue.
You can tolerate some plant and disease damage. A little black spot would not deter you from growing any other beautiful plant, so why should roses be any different?
In Paul’s 25 years of growing roses, he’s been an organic grower for 23. And he does that in upstate South Carolina, which is black-spot central and Japanese beetle central. He has around 300 rose plants, and he doesn’t spray any fungicides or insecticides and has no irrigation system.
Pick the Right Roses for Your Climate
Having the most successful organic rose garden that you can starts with plant selection. Look at what zone a plant is suited to and how big it will be at maturity. A rose that is meant for a warmer or cooler zone won’t thrive where you are, and if it doesn’t have adequate space to grow, it won’t be happy.
Roses are often sold as doing well in all parts of the country. Paul says this is wrong. Some roses do well in one part of the country but not in another. There are between 4,000 and 5,000 rose varieties in commerce in the United States. You can find a rose suited to wherever you live.
So how do you know if a variety is truly best for your zone and local climate? Paul says to go on social media and ask folks who live within 50 miles of you what roses they have had success with. Rose growers will be happy to tell you.
How to Start a Rose Garden
Most rose books recommend a 2-foot planting hole for each rose bush, but that’s not a directive that works everywhere. Where I am in Georgia and where Paul is in South Carolina, we have red clay. As Paul says, digging a 2-foot hole requires small explosives.
Paul preaches a whole-bed approach. “Prepare your entire bed,” he says. “Make sure that entire bed is full of life.”
And by life, he is referring to the soil microorganisms that flourish in healthy soil that’s been amended with compost and organic matter.
Though Paul has no irrigation system, in the first year, just to get new plants established, he hand waters. He recommends infrequent, deep watering to encourage the plants to grow deep roots. He waters in the morning so the plants have a chance to dry out in the sun and the foliage will not stay wet for a prolonged period of time, which fosters diseases. If he does water at night, he avoids getting the leaves wet.
I always avoid overhead watering to reduce any chances of fungal diseases taking hold. Pathogens really love wet foliage.
Also note that if there is a prolonged period of drought — three or four weeks without rain — then even established plants will benefit from supplemental watering.
Paul notes that in the 1970s, ’80s and ’90s, roses were bred for the flower rather than the health of the plant. This led to rose varieties that are susceptible to disease. Breeders didn’t need to worry themselves about disease, though, because just about any chemical you could imagine was available at the local hardware store in the United States, Paul says. When many chemicals were removed from the market due to deleterious effects on the environment or human health, roses with innate disease resistance became popular.
In 2000, Star Roses and Plants introduced the Knock Out rose to the American market. This rose, bred by William Radler, did not require chemical intervention to withstand disease pressure. A younger, chemical-adverse generation embraced the Knock Out rose, and the American nursery industry sought even more disease-resistant roses. However, rose breeding is no simple task. Paul says it takes 10 years, at minimum, to get a new rose to market.
There was at least one rose breeder who was well ahead of his time. In the 1970s or ’80s, Wilhelm Kordes of Kordes Roses in Germany quit spraying his rose test garden. Wilhelm was shocked by how poorly the roses did once he ceased spraying. Paul wonders how anyone could ever spray a test field in the first place: If roses are being doused in chemicals, how can their performance truly be tested?
Common Rose Diseases
Black spot, powdery mildew and rust are the diseases of most concern when it comes to roses, though they are all treated the same way.
The No. 1 way to deal with black spot is tolerance, Paul says. Black spot is not a death sentence at all. It will affect some leaves, some of which will drop off, but they will grow back again. If black spot is severe, you can apply copper fungicide, which is an organic solution for many fungal diseases. However, Paul says not to use copper fungicide as a preventative measure — if a rose bush doesn’t have black spot, it doesn’t need fungicide.
A rose that is susceptible to black spot where you live isn’t necessarily a bad rose. It may just not be a good rose for your climate. If Paul has a rose with recurring black spot issues, he pulls it out and plants something else.
Japanese Beetle Prevention for Roses
Paul is in one of the worst years he has ever dealt with when it comes to Japanese beetles on his roses. Japanese beetles are an invasive, destructive pest with no natural predators in North America. But Paul won’t go near any of the chemical treatments that are available for controlling Japanese beetles because he cares too much for the butterflies and bees that will also be affected by those sprays.
In the 40 days when Japanese beetles are present in his garden, starting at the end of May or the beginning of June, Paul implements non-chemical methods of control.
Japanese beetle traps, which lure the pests with an attractant, often get a bad rap because they can bring the beetles into a garden. But Paul says it’s a matter of how the traps are used. If the traps are placed 30 or 40 feet downwind of a rose garden, the beetles will reach the trap before they reach the garden.
Paul notes that organic pest control is about multiple lines of defense and not one single magic bullet. Method two for Paul is to go out early in the morning and knock the Japanese beetles into a cup of soapy water. When tapped, the beetles just fall to the ground — so catch them before they have a chance to fly back onto your plants.
Paul’s other control is to groom his rose bushes midsummer, reducing their size, removing deadwood and taking off flowers. With fewer flowers, the plants will be less attractive to Japanese beetles. When the roses wake up again in fall, the beetles are gone.
Aphid & Thrip Control for Roses
Aphids, thrips and midges are other common rose pests. Paul’s strategy is to plant perennials that attract the insects that prey on aphids. The beneficial insects will eat most of the aphids but not all of them. That means more beneficials keep on coming to dine on aphids, and those beneficials will continue to be present when thrips show up later.
If you use a chemical that wipes out all aphids, beneficial predatory insects have no reason to be there in your garden. Then when the thrips arrive, no beneficial insects are waiting for them.
When and How to Prune Roses
The conventional wisdom for pruning roses is 18 inches high with an outward-facing bud eye, but Paul says that’s advice for rose exhibitors, not the average gardener. What Paul tries to achieve is a full shrub with lots of flowers.
The question to ask is, what is the rose’s job in the garden? If it’s a traditional English border, is it frontal border, back border or mid-border? Is it a hedge for privacy? Is it low along the sidewalk?
The lower you prune, the longer the stems will be, and you’ll get fewer but bigger flowers. Paul advises considering the height of the plant at maturity and removing just a third. If you desire a variety that maxes out at 2 feet tall, let it grow to 2 feet tall before removing a third. If you want a 10-foot-tall hedge, pick a variety that grows that tall, and remove a third at pruning time.
The other pruning consideration is dead and diseased stems. You can remove these when you find them.
To keep plants from clogging in the center, prune to the top of an outward-facing bud eye. That means finding the spot on the stem where a cane will grow facing out. This will reduce the problems of cluttered centers and crossing canes.
Spring-flowering roses — the old European roses, such as Gallicas, Damasks, Albas and Centifolias — only bloom on old growth. The time to prune is right after it flowers in spring.
Modern roses that bloom from spring through fall can be pruned at any time. In areas with a cold winter, Paul advises pruning when the forsythia blooms, because the forsythia is a harbinger of spring.
Bush roses, like hybrid tea, floribunda, David Austin or old-fashioned tea roses, can all follow these rules.
Then there are the climbing roses. Climbing roses have main canes that form the structure of the plants, and they have laterals, or side shoots. The side shoots bear the flowers. Never cut a main cane, Paul says. If you do, the plant will put its energy into regrowing its main cane rather than into flowering. For the side shoots, you can prune all season long after the plant has flowered. You can prune side shoots within 14 inches of the main cane for a more formal look, or to within 3 feet for a more sprawling look.
The main cane should be trained to grow horizontally to encourage more laterals and more blooms. To go up an arbor, canes may be trained to a 45-degree angle to zigzag upward.
I hope you feel inspired after hearing from Paul Zimmerman and learned something about growing roses. If you haven’t listened yet, you can do so now by clicking the Play button on the green bar near the top of this post.
What tips do you have for growing roses? Let us know in the comments below.
Links & Resources
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joegardener Online Gardening Academy Perfect Soil Recipe Master Class: Learn how to create the perfect soil environment for thriving plants.
joegardener Online Gardening Academy Beginning Gardener Fundamentals: Essential principles to know to create a thriving garden.
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“Everyday Roses: How to Grow Knock Out and Other Easy-Care Garden Roses” by Paul Zimmerman
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