Native plants and water control

By Ellen Barcel

In last week’s gardening column, we looked at the frequently erratic amounts of water that Mother Nature provides to Long Island gardeners. This has been a dry spring, for example, with moderate drought conditions being reported for April and most of May. How do we deal with this?

One of the answers is by planting trees, shrubs, etc. that are native to Long Island. This way, they are plants that are already adapted to the almost pendulum-like swings between torrential rain and near drought conditions.

Native plants have other benefits, besides the amount of water they need. They are adapted in other ways, too. For example, they survive the winter cold and summer heat better than some introduced plants. Native plants need little or no fertilization. They are noninvasive (not like the English ivy, which if given an inch will take a mile).

Native trees have generally reached a balance with insect pests native to the area. You’ll notice that the insects that have caused recent problems in local trees (Asian longhorn beetle and southern pine beetle) are not from our area.

Trees
Trees that do particularly well on Long Island, and are actually native to the area, include pine and oak. Oak has a taproot, which goes deeply into the soil. This is a benefit in times of little or no rain because it’s the top layer of soil that dries out. Deep down, there’s water in the soil and the taproots reach deeply into those wet layers. The USDA Forest Service notes that pine has a vestige of a taproot and three to five other major roots that go outward and then deep into the soil. Native dogwood is another one that does well here.

Shrubs
Shrubs native to the area include northern bayberry (Morella pensylvanica), bear oak (Quercus ilicifolia) and blueberry. Blueberry in particular does well on Long Island because it prefers a soil with an acidity somewhere in the neighborhood of 4.0 to 5.0, very acidic. And, fortunately, Long Island soil can be as acidic as that. Blueberries come in a variety of heights and bloom times so they make a beautiful living hedge and can provide fruit for over a six-week period.
Note that wineberries, which grow so easily here, are not native but have been introduced and are very invasive. They are on Suffolk County’s Do Not Sell list because of their invasive nature. Another introduced, and invasive, shrub is the multifora rose. Again, banned and definitely invasive.

Flowers
Annual, biennial and perennial plants that are native to Long Island include aster (purple flowers in autumn), butterfly weed (Asclepias tuberosa, with its vibrant orange flowers in summer), clover and Eastern prickly pear cactus (bright yellow flowers with orange centers, also in summer). So, yes, you can have a beautiful flower garden with just native plants.
While native plants are ideal, there are also some nonnative plants that have similar characteristics. Look for plants that are drought tolerant, noninvasive and do well in USDA hardiness zone 7 or above (my preference is for 6 or above, just in case we have abnormally cold winters).
For detailed information on native plants, the Brooklyn Botanic Garden publishes “A Native Plants Reader” and “Great Natives for Tough Places.” “Native Alternatives to Invasive Plants” by C. Colston Burrewll, handbook 185, may be available as used copies. Go to www.bbg.org for details. See also the website of the Long Island Native Plant Initiative at www.linpi.org.

Ellen Barcel is a freelance writer and master gardener. To reach Cornell Cooperative Extension and its Master Gardener program, call 631-727-7850.