A hands-on gardener for 30 years, Deb Terrill has written for a number of publications. After formal training in landscape design, she operated a landscape and gardening business and later became a syndicated columnist. She also monitors moths for The Nature Conservancy.

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Site-Sensitive Natives
by Deb Terrill    

Just because it’s a native doesn’t mean it will be happy wherever you plant it.

There are a lot of terrific reasons to grow native plants, but the most-cited reasons are not necessarily the best. There is little doubt that natives are hot. From two-minute TV segments to print media and even garden club lectures, you can’t avoid the message: “Grow native plants because they are easier, need less water and care and are better for the environment.” But is it true?

Natives are Carefree

This is only true if you are establishing a native habitat that will be kept in a natural state year round. If you don’t mind looking at dormant plants all winter and waiting for the old growth to be swallowed up by the new in the spring, then yes, natives can be less labor intensive.

But for those gardeners whose village regulations don’t permit this look or who like things tidier, then you will need to do the same cutting back that you would expect with any perennial bed. Weeds do grow up in native plantings, and some native plants get a little too seedy, taking over the garden. So plan on weeding and deadheading, too.

Natives Use Less Water

Most claims even go so far as to say no watering is necessary after the plants are established. Well, true, if you live in a wetland. The back story here is that all plants live in a particular kind of ecosystem and have a fairly specific group of plant partners. The matrix (soil, plant community and hydrology) of an oak forest, for example, is much different from that of a short grass prairie. The individual plants in each would not thrive if moved to the community of the other.

For example, using a plant like ironweed (Vernonia altissima) in your sandy garden soil will not work unless you water copiously and constantly. On the other hand, something like butterfly milkweed (Asclepias tuberosa), which grows on sand hills in the wild, will mildew and rot away in an average garden setting. In other words, you must match the native plant to your particular garden microclimate, just as you would with non-native species. Grow native Joe Pye weed (Eupatorium purpureum) if you want to see how fast a plant can wilt from lack of moisture.

In addition to having specific moisture requirements, native plants are also pH sensitive such as any other plant. Some, such as bird’s foot violet, native holly shrubs or maidenhair fern, will simply not tolerate our mostly alkaline soils. Others are even more finicky, needing the presence of certain fungi and host plants to succeed. This includes all native orchids such as the lady’s slipper. Birch, beech and pine trees will also be affected to a degree.

Native Plants Encourage Wildlife

Yes, indeed they do. The single best reason to include native plants in your garden is to create a chain of natural bridges across the vast expanse of habitat destruction in which we live. Whether in beachfront Florida, where palm trees are being discouraged in favor of erosion-controlling, butterfly-supporting grasses, or in New York high rises where folks are growing rooftop milkweeds for monarchs, we are finally realizing that we can make a difference to birds, bees and butterflies. Every garden should include plants that support that effort.

Native Plants are Healthier for the Environment

I think it’s safe to say that just as many chemicals are being used to fight pests of redbuds, dogwoods, oaks, maples, white pines and river birch as any group of non-native trees. In fact, the single largest plant disease problem of Midwestern gardens, cedar apple rust, exists due to the extensive use of Juniperus virginiana, a native evergreen. This popular landscape plant serves as the alternate host for the fungal infection that defoliates our crab and hawthorn trees every summer.

Native forbs are just as likely to develop pests as non-native perennials. Anyone who has grown butterfly milkweed is familiar with the orange coating of aphids that covers the plant, as well as the milkweed beetles that crawl over the blooms. In fact, the very reason we should grow these plants includes the certainty that they will be eaten. You can’t grow milkweed for monarchs or violets for fritillaries and expect that the foliage will not be eaten.

Once again, if you are replacing a lawn and traditional garden with a natural meadow that will remain untouched, then yes, it will require the use of fewer chemicals and be healthier (as long as you can keep it free of ragweed, that is.) And such a natural garden will filter water as it percolates through the ground, cleaning it and maintaining a safer water supply.

Moreover, every time you add a native plant to your garden, you are increasing the chances of its attracting beneficial birds, butterflies and other insects. Adding to the biodiversity of the area where you live is a major reason to grow native plants.

Native Plants are Never Invasive

This one is tricky. Scientists have very specific definitions about what constitutes an “invasive” plant. On its website, the USDA’s Natural Resources Conservation Service (NRCS) for example, lists federal and state-defined “Invasive and Noxious Weeds.” There is a growing number of non-native plants that have become a real threat to our remaining natural spaces. They include Japanese honeysuckle, purple loosestrife, buckthorn, crown vetch, kudzu (yes, it has reached Chicago) and garlic mustard.

Some native plants, however, can and do become aggressive in our gardens. I spend an awful lot of time removing mulberries and elms from my garden and I have spent years trying to eradicate violets and the hairy petunia I planted in my rock garden a decade ago. It is still in the lawn and pops up in sidewalk and patio cracks when I least expect it. It simply didn’t have the checks and balances of its natural plant matrix (woodland) in my garden. The Northern sea oats, whose fishtail seedheads I prize, can become invasive when the seeds are allowed to drop.

It is safer to say that native plants are like any other plant. They have a preferred habitat that requires consideration when we select them for our gardens. All plants require maintenance and succumb to insect and disease damage.

Some of the plants I most appreciate in my garden happen to be natives. I can’t imagine spring without Virginia bluebells, trout lilies and the lovely double bloodroot. And it is the reds of sumac, serviceberry and sugar maples, and the yellows of Solomon’s seal, Arkansas amsonia and bowman’s root that get me through November.

 

Easy Natives for Most Gardens

These plants do well in most soils, but they do have preferences and will do better if sited where they are happiest.

Perennials for Shade:

• Wild columbine (Aquilegia canadensis) — dry to medium soils

• Goatsbeard (Aruncus dioecus) — medium to moist soils

• Wild ginger (Asarum canadense) — medium to moist soils

• Bowman’s root (Gillenia trifoliate) — moist, acid to neutral, humus-rich soil, drought-tolerant once established

• Virginia bluebells (Mertensia virginica) — medium to moist soils

• Mayapple (Podophyllum peltatum) — grows in any well-drained soil in shade and in full sun in rich, heavy soil


Mayapple
Photo: Pamela J. Bennett

• Double bloodroot (Sanguinaria canadensis f. multiplex ‘Plena’) — medium to moist soils. Note: this is a naturally occurring form, not a cultivar

• Celandine poppy (Stylophorum diphyllum) — medium to moist soils

• Red trillium (Trillium erectum) — dry to medium soils

Perennials for Sun:

• New England aster (Aster novae-angliae) — medium to moist soils


New England aster
Photo Courtesy of Prairie Nursery

• Poppy mallow (Callirhoe involucrata) — dry to sandy soils

• Purple coneflower (Echinacea purpurea) — dry to medium soils

• Sunflowers (Helianthus sp.) — dry to medium soils

• Black-eyed Susan (Rudbeckia hirta) — dry to moist soils

• Brown-eyed Susan (Rudbeckia triloba) — medium to moist soils

• Showy goldenrod (Solidago speciosa) — dry to medium soils

Woody Plants for Sun:

• Red maple (Acer rubrum) — moist acidic soils

• Sugar maple (Acer sacharrum) — well-drained moist fertile soils

• Sumac (Rhus typhina) — dry to poor soils; no shade

• White oak (Quercus alba) — acidic soils

Woody Plants for Sun to Shade:

• Serviceberry (Amelanchier sp.) — prefers moist, well-drained, rich, organic, acidic soils in partial sun, but will tolerate a range of situations.

• Viburnum (Viburnum sp.) — many species so needs vary, but in general, moist but well-drained soil in full sun to partial shade; some prefer dry soil.

 

Posted: 06/18/12   RSS | Print

 

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COMMENTS

Ellen Honeycutt (Atlanta, GA) - 07/08/2012

A good summary! The main reason I use natives is to support the local critters - insects that eat the foliage (just a bit, not a lot!) which in turn are food for birds (especially baby birds that which eat insects exclusively). Supporting the critters naturally has made my yard come alive.

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