The right cross

The right cross

Raymond Evison has spent 50 years breeding clematis, and is still searching for the perfect cross.

January 13, 2015

Raymond Evison has been fascinated with clematis for more than 50 years, and he believes there is still more work to be done with the plant.

He raised his first new clematis cultivar when he was 18 years old. He named it Edith, after his mother. Now 70, the legendary British breeder is showing no signs of slowing. Over the summer, he won his 26th gold medal at the Royal Horticulture Society’s annual Chelsea Flower Show, and visited several U.S. garden centers on a mission to help retailers better understand the flowering clematis with the distinctive blue label.

“I believe we offer some of the best new clematis that come to market,” he says. “So, we’re really there to hold our customers’ and our customers’ customers’ hands to make sure they do a good job on the retailing.”

The business of breeding

Evison’s breeding really took off in 1992, when he formed a joint venture with the Poulsen Rosa Company from Denmark. Poulsen Rosa was known for rose breeding, and Evison hoped to leverage that knowledge, as well as the company’s experience with plant patenting, with his knowledge of clematis.

“We decided that we wanted to produce more compact clematis, because we knew people would be using smaller gardens,” he says. “We wanted clematis that were more free-flowering and producing more flowers, and were much more compact in their habit.”

Serious clematis breeding started in the early- to mid-1800s. Despite growing to eight- or nine-feet tall, many of the varieties from that era have just one, single large flower at the end of a growing stem. There were about 500 cultivars listed by the beginning of the 20th century, Evison says. Many of those have been lost, but Evison still grows about 50 of them.

“We then listed up 10 to 15 criteria that we wanted our mother plants to have,” he says. “Many of the ones that we actually used in that early breeding program were cultivars from the early 1800s.”

As part of the joint venture, Evison licensed growers around the world to propagate his plants under the brand name Raymond Evison Clematis. Of course, Evison’s own Guernsey Clematis Nursery is one of the licensees. Located on 8½ acres in Guernsey, a small island in the English Channel, the nursery produces about three million clematis plants annually and has about 90 employees during peak times. Evison estimates that his nursery produces about 20 percent of the world market for young clematis plants.

Select North American growers that are licensed to grow Raymond Evison brand clematis receive a few cultivars every year to add to their range.

After the nurseries have grown the plants for two years, they sell them to retailers. If those garden centers participate in the Evison-branded plant program, then they are listed on the brand’s website. Evison has about 800 garden centers in North America and the U.K. that are brand retailers.

Though this is the last year of Evison and Poulsen’s arrangement, Evison’s breeding will continue.

“They wanted to do other things, so we haven’t fallen out or anything like that,” he says.

When Evison and Poulsen had their program running at full-speed as it were, they would do about 2,500 crosses a year. That would generate 35,000-40,000 seeds, which would generate about 10,000 seedlings. After a four- to five-year evaluation and selection process, only five or six of those seedlings make it to market. It takes about 10 years from the time of pollination to actually putting a new clematis on the market.

“The breeding work that my team and I are doing this year, I’m going to be 80 before those are on the market,” Evison says. “I think the consumer thinks these things happen overnight, but we really need to do the evaluation process and be certain that the plants don’t succumb to mildew. We’re very rigorous with our selection work.”

Before Evison sends a plant to market, its strength and constitution is tested. It won’t succumb to mildew unless it is placed in ideal conditions for breeding mildew.

“With the very rigorous selection process, anything – even if it’s a fantastic color break in the plant – and the plant doesn’t have a good constitution, then I’m afraid it gets thrown away in the skip,” he says.

Clematis wilt also affects clematis in gardens, but Evison says he hasn’t seen that in his nursery for many years.

Breeding a better clematis

Evison’s clematis selection process is very detailed. The first evaluation is during a one-year period. New cultivars are selected in the spring. In the summer, the plants are cut down and then re-flowered. Then, they are examined again in mid-summer to early autumn. Evison says that seeing the plant at different times of the year is important.

Evison looks for plants that are “free-flowering.” In the context of clematis, that means they will produce a lot of flowers up along their stems. The older clematis cultivars have a stem, a stalk, and one flower at the top. Some of the cultivars Evison has developed have five, six or even seven leaf axle nodes that produce flowering buds, as well. And those flowering buds produce second flowering buds. That trait is valuable in a clematis, and that is one area Evison focuses on in selection.

Color is another important factor. Evison aims for colors that don’t fade, unless that fade creates an attractive, eye-catching look.

“We’re certainly looking for different colors, color breaks, and we’re looking for really strong colors,” he says. “There’s also a market for the pale pinks and the whites. We also look for if the flower has a good shape. Maybe the shape is very, very different, so we’re not always looking for round-shaped flowers or things that have pointed sepals, but we’re looking for a plant that will say to the consumer, ‘Pick me up and buy me.’”

Evison also has focused on breeding and developing more fully double-flowered clematis because of how much those resonate with the consumer.

The North American market has been challenging for clematis breeders because of the severe winters in much of the country. There’s a lot of winter kill with the single large-flowered clematis in that market, and all the top rows get killed down to ground level. Many of the older varieties of double clematis raised in the 1800s and early 1900s will not produce any double flowers after winter kill, because the double or the semi-double flowers come from the previous season’s ripened stems. This is a problem that Evison has been working to solve.

“The advantage of our clematis is that even if they are early flowering and even if it has been a severe winter, they will flower still quite early on in the season. If you had an old fashioned ‘Nelly Moser’ – they’re still a good clematis – and they got killed down to ground level, you probably wouldn’t see any flowers until about August or so. Our new varieties we’ve selected flower very profusely on the old wood or the new growth.”

Evison’s most popular cultivar is clematis ‘Rebecca.’ Named after his eldest daughter, its calling card is its dramatic, large red flowers.

One cultivar that stateside growers should watch for is clematis ‘Samaritan Jo.’ It is new for 2014 in the U.S. It has a silvery-pink center and darker purple coloring on its edges. Evison says it’s very free flowering and ideal for growing up into roses. It also works well in containers. ‘Parisienne’ is another cultivar that excels in containers due to its compact nature. It boasts violet flowers with a dark red center, and has been one of Evison’s best sellers since its introduction in 2005.

Evison has even worked with British royalty on some of his cultivars. “If you have a shady deck or patio, then ‘The Countess of Wessex’ is very good,” Evison says. “We launched that with the countess in Chelsea in 2012.”

A misunderstood plant

Evison breaks down his new cultivars into several groups. The Regal collection are double-flowered clematis that can be grown in pots and containers or walls or trellises. The Boulevard collection is made up of compact plants that are ideal for smaller pots and gardens.

“You don’t have to have a six-foot wall to grow clematis,” Evison says. “I’m very keen that clematis are grown with other plant material and not just on a plain trellis.”

In fact, Evison’s most recent book, “Clematis for Small Spaces,” details 150 of the best clematis cultivars for patios and balconies. He wants to make sure today’s consumers are educated about the plant, which he says is often misunderstood.

“They’ve read in books or magazines what complicated plants they are,” Evison says. “This is one thing that I would like to stress from our breeding point of view and particularly from the garden center point of view. With our new clematis – the Evison-Poulson clematis – for the singles and the doubles quite simply, reduce their top growth by one-third every spring. That’s at the end of winter just before bud break. With all of our other single ones, we’ve simply introduced a technique called ‘the ponytail cut.’ You grab the growth and you chop it off 6 to 9 inches above soil level. That can apply to all varieties that are not double or semi-double. That, again, you do in the winter or early spring. It’s really simple. People haven’t got to get their reference books out knowing what bit to cut out and what bit to leave and all the rest of it. As we’ve developed these clematis, you can be pretty ruthless. Chop off the top growth and away they grow and flower.”

In the future, Evison wants to breed cultivars with improved cold hardiness. He’s working with the idea of producing more fibrous roots that could withstand colder winters without needing to take the plant indoors.

Every little improvement he makes demonstrates the value of breeding. He believes growers and consumers shouldn’t shy away from paying more for the better mildew tolerance, double flowering, and easier pruning available with his branded clematis.

“Nurserymen and the consumer should not be thinking purely about price,” Evison says. “They should be thinking of the quality of the plants. Sometimes people will say, ‘I don’t want to buy that. It’s got a royalty on it. It’s too expensive.’ I think the consumer and the nursery industry need to consider that a lot of time goes into the breeding and developing of new plants. That has to be rewarded with royalty collection. Some of the old varieties are still very, very good, but they do not perform in the way that our new ones perform.”


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