Are You a Conehead?

Most gardeners are familiar with the old standard purple coneflower (Echinacea). It is a tough, native North American plant that has adapted to a wide range of environments. Coneflowers take hot, dry conditions and poor soil without complaint and yet they handle extreme cold and wet conditions with equal ease.

Coneflowers are low maintenance, vigorous bloomers that spread easily and make wonderful, long lasting cut flowers. Butterflies love them and the seeds produced in the fall are great for attracting birds to the garden. They sound pretty perfect, right? Well, in the gardening world, they are darn close.

Non-gardeners are familiar with Echinacea as an herbal remedy that helps ward off colds, flu and other infections. Echinacea has been shown to stimulate the body’s natural immune system thereby helping your body fight off disease.

An interesting bit of trivia…the genus name, Echinacea, comes from the Latin name for hedgehog which refers to the prickly lower stems.

Although the native coneflowers are wonderful plants, the new hybrids that have become available in the last few years are nothing short of brilliant. In addition to the traditional purple, there are now many shades of orange, yellow, pink, green and white. The best thing about these new hybrids is that, in addition to the exciting new characteristics they offer, they manage to retain the vigor and adaptability of their native cousins.

There are two primary researchers responsible for these new introductions. Dr. Jim Ault of the Chicago Botanic Garden and Richard Saul of Itsaul Plants in Atlanta, Georgia.

Dr Ault spent seven years developing the Meadowbrite series, with ‘Art’s Pride’ or ‘Orange Meadowbrite’ being the first release. It features tangerine orange flowers and a sweet, spicy fragrance on two to three foot sturdy plants. The series also includes ‘Mango’ and ‘Pixie.’

Richard Saul calls the interest in and development of new coneflowers the ‘cone craze.’ His claim to fame is the long-blooming Big Sky series. This includes ‘Summer Sky,’ the first bi-color coneflower as well as ‘Harvest Moon,’ a golden yellow variety, ‘After Midnight,’ which is magenta and ‘Sunrise’ and ‘Sunset,’ citron yellow and intense orange respectively.

‘Green Envy’ was developed by hobbyist gardener Mark Veeder. This one is a jaw dropper. The green portion of the petal slowly fades to magenta, creating a beautiful bi-color effect. The tips of the petals remain green for up to a month.

“Coconut Lime’ is the first double flowered white coneflower.

Other double flowered varieties include ‘Razzmatazz’ and “Pink Double Delight.’ And don’t forget ‘All That Jazz,’ which I mentioned in an earlier column. It features quill shaped petals that resemble spoons.

There are so many new and interesting coneflowers to choose from, it’s easy to see why so many gardeners are becoming ‘coneheads.’ If you don’t want to be left out of this newest craze, you better plant one or two this year.

And Yet More Shrubs!

Spireas have gotten a bad rap over the years and I must own to the fact that I have been one their detractors. You see, I grew up with the ubiquitous overgrown ‘Bridal Wreath’ spirea in our yard and for years I steered clear of all spirea because I just never liked that plant. I know. That’s unfair and it’s really a very nice shrub.

In fact I now admit that as a whole, spireas have many useful qualities. They are small to mid-size shrubs that fit well into any size yard and they are extremely low maintenance. Their attractive foliage adds interest even when they are not in flower and they are pretty much indestructible. There are nearly 100 species to choose from including ‘Gold Flame,’ ‘Magic Carpet,’ ‘Lime Mound’ and ‘Shibori,’ which has white, pink and red flowers all on one plant. My pick would have to be Spiraea thunbergii ‘Ogon.’ It is a small spirea that flowers very early and has beautiful delicate golden foliage. It’s a little tender here, but worth the effort.

With all they have to offer, I think that every gardener should find a place for at least one spirea in their yard. Hey, we’re all allowed to change our minds.

Last week I discussed the merits of the newer cold-hardy varieties of hydrangeas. Well, we mid-Iowa gardeners are also benefiting from the recent hybridization being done with azaleas and rhododendrons. Most of their traditional cultivars are meant for warmer climates than ours, but a few of the newer ones will winter over quite well here.

Azaleas are technically a sub-species of rhododendron so their cultural needs are pretty much the same. All will do best in part shade and they prefer slightly acidic, well-drained soil. Mulching them will help to retain soil moisture as the roots can’t take excessive heat or dry conditions.
In 1978, the University of Minnesota introduced the first in it’s now prized ‘Northern Lights’ series of azaleas. Today, there are upwards of a dozen varieties in the series in a wide range of colors. Their flower buds are hardy to at least 30 below zero, so the blooms are very reliable here in central Iowa. Rhododendron ‘PJM’ hybrids have buds that are equally hardy. They all have vivid lavender-pink flowers in April or early May and foliage that turns mahogany in the fall and winter.

For years, weigelas were considered horticultural relics, but now with the many new hybrids available, they are coming back into favor.
They prefer full sun but can withstand part shade and they are adaptable to many soil types. They generally grow from three to six feet. Many new cultivars, such as ‘Tango,’ a Canadian introduction, have colorful foliage and bold flower colors. One of the best weigela was developed right here at Iowa State University. ‘Red Prince’ is a very hardy re-bloomer. ‘White Knight’ was also developed at ISU and also will re-bloom if dead-headed.

And then there is Buddleia davidii, more commonly known as butterfly bush. As the name implies, it’s a magnets for butterflies and hummingbirds. The fragrant flowers are bottle-brush shaped and they come in a rainbow of colors, including bi-colors. In our climate, butterfly bushes should be treated as herbaceous perennials rather than shrubs. By that I mean they should be cut back to the ground in the spring. They never fail to put on an abundant flower display in my garden and as with some of the other flowering shrubs, they will re-bloom if dead-headed.

So after all this, what is my favorite flowering shrub? Mock Orange (Philadelphus) hands down. I have three different varieties in my garden. Why the passion for a plant that is rather average looking most of the year? Simple. The fragrance is as close to heaven on earth as you can get. The pure white flowers range from single, semi-double to fully double and can be up to 2 inches across. They have an intense sweet, citrusy aroma that bowls you over when it hits you. Mock Orange ‘Aureus,’ with lime green leaves is the most fragrant one I have. ‘Innocence’ has beautiful variegated leaves. Be sure to plant mock orange near patios and walkways to take full advantage of their best feature.

A few other flowering shrubs you may want to consider are viburnums, shrub roses, flowering almonds (Prunus glandulosa) and blue mist shrubs (Caryopteris).