Which Plants To Pick?

A few decades ago the nursery industry was in one of its periodic slumps when they decided on a new marketing strategy to extend their business season and thus our planting season(s). You can still see some vestiges in promotional material and at some garden centers when the signs go up proclaiming “Fall Is for Planting.” And it’s true. For many plants, late summer and fall are perfect times for planting.Obviously it’s when we plant the majority of our spring flowering bulbs, and mid to late fall is a great time for planting deciduous trees, as the above-ground portions of the trees go dormant while the root systems actively and vigorously continue to grow.

But there’s still a dearth of plant material available at garden centers because the retailers justifiably don’t want to get stuck with an inventory of trees, shrubs and perennials that they then have to overwinter. Mail order nurseries, however, don’t have this issue, so they remain a great source for fall planting material. And local garden centers will do some stocking, though it’s really a great time to find bargains as they try to close out their inventories for 2014.

This all brings us to the larger question of what to buy? How do you know what tree is the best of a variety? Which is the most outstanding hydrangea, what’s the most reliable magnolia, and what heuchera, of the scores that are on the market, will perform best out here—to say nothing of the myriad echinaceas?

Making these decisions is not at all easy. If you’re impulsive and get wowed by the pictures you see in the catalogs and magazines, you’re likely to buy something that looks and grows great in ideal conditions, and while I hope you have them, most of us are stuck with less than perfect soil, water and weather. Many of us lost buddleias due to the cold from last winter in spite of most of the varieties being sold as being hardy to zone 4 and 5. They weren’t. I lost a really nice magnolia (Spring Peppermint) that came from a nursery in the colder Midwest and was supposed to be zone 5 hardy. There were many reports of clematis being lost or dying back to the point where in previous years they’d grow 12 to 15 feet and this summer barley pushed out 6 feet of growth.

We’ve been misled by overzealous marketing and poor long-term trials by breeders and wholesale growers who are more eager to sell than do long-term trials. It’s understandable, though, when you stop to consider how many years it can take to trial a tree or shrub. We’ve also been misled by less than scrupulous marketing segments of the rose industry and to a lesser degree the perennial growers, but there are sources of good information on what plants are reliable and field tested ... if you’re interested and willing to search.

First, there are your neighbors. If you have a neighbor or friend who’s a plant maven, ask them for advice. They may have been growing roses, or figs or day lilies or Japanese maples for years and have a good idea what’s worked for them, and that should be a good indicator of what will work for you. There’s also information available from local horticultural groups and garden clubs.

But if you’re looking for good independent information you need to go to sources that are conducting trials. If magnolias are your thing, the Brooklyn Botanic Garden not only did trials, but also had a breeding program on magnolias for many years. At the garden they maintain a collection of more than 70 magnolia specimens. The Chicago Botanic Garden has a long-term project in evaluating herbaceous perennials, trees and shrubs and you can get great information there. They’ve done some great evaluations on 37 different plants over the past 28 years. They evaluate perennial candidates for four years, shrubs for six years and trees for seven to 10 years. Their latest trials are on Joe-Pye weed, which is a great candidate for the wildflower gardeners out here. The Pennsylvania Horticulture Society has a trials program, and out here Cornell Cooperative Extension in Riverhead has been doing trials with annuals. They have a trial garden that you can visit to see the results: http://ccesuffolk.org/long-island-trial-gardens/.

And yes, even the Hampton Gardener has trial gardens. Each year I get about two dozen plants from a group of breeders and growers that I trial. Though I tend to stick solely to perennials, each year one grower sends me several boxes of plants to trial, and invariably some annuals are included. I usually give the annuals to gardeners I know and ask them to grow them and report back. They don’t, though, and I really don’t follow up. But one plant that keeps on showing up to be trialed is a hybrid petunia from Proven Winners called Supertunia.

Well, this past summer a friend of mine was very ill and his wife asked if I could plant a few things for them. The Supertunia Bordeaux ended up being one of the annuals I selected, based on its color, habit and availability. I had a few 6-inch pots left over, so I set them in front of my garage in June and ignored them for about eight weeks. Once in a while, someone would pass them and give them some water, but more often the soil was dry. The plants are being benignly neglected, but they are thriving. They don’t mind a little drought, thrive in sun, continue to push out lasting vibrant blooms, and grow with no pinching—so I’m impressed. This annual certainly gets five green thumbs.

On the heuchera front, I certainly have my favorites of the more than 30 varieties I’ve trialed. I’ve been growing Caramel and Beaujolais and I think the combination has really great color and a tight and mounded habit. They are not long lived, so I replenish every other year, but when allowed to grow into each other these plants really add subtle but noticeable color to a lightly shaded area.

Little Cutie is a heuchera that I’d say has great promise. It’s only in the first year of trial, so I can’t speak to its hardiness, but it’s one of the smaller heucheras with a tight mounding habit and unusual but attractive yellow flowers on 10-inch stems above the plants lasting all summer. The fourth selection is Sugar Plum, which, when planted in a group of five or more, provides a very agreeable display of foliage that’s pewter in color with purple and interesting venation. It’s been in my trials for three years, available for sale this year and remarkably winter hardy, with the foliage lasting very late into November. I use it to edge a rock path and it doesn’t get leggy and needs virtually no care.

Next week some thoughts on the new echinaceas, an incredible new perennial geranium that doesn’t know how to quit, some mums that flower twice, a remarkably hardy red hot poker, something old that’s delightfully new and more. In the meantime, time to shop for bargains and keep growing.