Saturday, April 19, 2008

What's New in the world of Perennials

Companies selling perennial plants are always trying to come out with “new “ and “improved” offerings. Unfortunately many of these new perennials are developed in warmer climates and don’t survive in northeast Vermont.

Terra Nova Nurseries in Oregon has registered 500 new perennials since 1992. I can highly recommend some of their introductions, while I have grown others with no success.

‘Excalibur’ and ‘Majeste’ pulmonaria have attractive silver foliage, and because the leaves have a fuzzy characteristic, deer don’t eat them.

Pulmonaria has many common names, such as “Bethlehem sage” or “Mary and Joseph plant” (because the bloom on the species goes from pink to blue) or “lungwort.” ‘David Ward’ pulmonaria has green leaves with a silver edge and coral red flowers.

Perennials do not bloom all season, so I encourage people to consider the color and texture of the foliage when planting a perennial garden. A planting of maroon foliage next to silver foliage can give the impression of color without one bloom. And foliage color is one place the perennial plant industry has made great advances.

There are many heucheras (coral bells) with maroon and purple leaves. Among the best are ‘Plum Pudding,’ ‘Chocolate Ruffles,’ and ‘Purple Petticoats.’ Ligularia ‘Britt Marie Crawford’ has wonderful large dark leaves and there are numerous new cimicfugias (snakeroot) out there with almost black foliage and names like ‘Black Negligé’ and ‘Hillside Black Beauty.’

I like variegated foliage, but it often reverts back to solid green. The relatively new Jacob's ladder, ‘Stairway to Heaven’ seems to hold its variegation nicely.

I like the way the yellow blooms of heliopsis (false sunflower) ‘Lorraine Sunshine’ look against that plant’s variegated foliage.

Sometimes new introductions get a lot of press and gardeners then ask for these plants. I have not had luck with the yellow and orange echinacea (cone flower) over wintering, nor do the yellow leafed heuchera do well for me.

I have seen plants thriving in Montpelier and Barre that I have difficulty growing here because we are just that much colder.

A few years ago I had a landscaper beg for a new daylily, ‘Rosy Returns,’ which promised “... large (4") bright rose flowers with repeat blooming from June to frost. “ I planted 50 of the expensive new plants to evaluate their performance. The flowers, when they did appear, were muddy and after three years of giving them a chance, they all went to the compost pile.

That said, daylilies are a good place to find something “new” that will stand out in the garden. There are about 50,000 registered cultivars and hybridizers are always trying to come up with something different. Daylilies now come in just about every color except true blue, and all shapes from one inch across to a spread of nine inches. There are doubles, “spiders” and “UFO’s”. There are bright red daylilies and white daylilies. A good time to buy daylilies is when they are blooming, because color photographs are often misleading.

Another perennial which has seen improvement over the years is the perennial geranium. These smallish plants are not the geraniums with big red flowers sold every spring in pots. Those are actually in another group altogether and their botanical name is Pelargonium, not Geranium.

True hardy or perennial geraniums belong to the genus Geranium. You will sometimes see them referred to as cranesbill geraniums, because their seed pods are said to resemble a crane's bill. They are low growing plants that spread by rhizomes. The foliage is often toothed and remains attractive. The flowers float on top of the plant.

‘Rozanne’ geranium has been named the 2008 Perennial Plant Association “plant of the year.” It has violet blue flowers and is long blooming.

‘Splish Splash’ is a newer hybrid that grows into a larger plant than most geraniums, reaching 30". The flowers are like small white petunias with splashes of blue ink.

One of the darkest and most intensely colored hardy geraniums is 'Perfect Storm.' It has magenta-pink blooms with a black center and dark veins, which are set against pale gray-green foliage, making the flowers really stand out .

Sometimes a “new” perennial is rated zone 5 and is fine overwintering in my Cabot garden. Other plants promising zone 3 hardiness don’t survive. A gardener’s best bet is to shop locally from people who have experience growing the plants they sell. (Imagine I should give that advice!) The quality of these plants will be much better than mail order and the price will be less.

While it’s fun to try new introductions, gardeners have a vast choice when it comes to perennials and some of the oldest cultivars remain the best.

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