Ecological gardens–sometimes called forest gardens–are based on natural native or naturalized plant groupings or communities in your region. I’ve been looking into the concept and have felt for some time that the hardest part about planning this type of garden is knowing what to plant. OK, you know that in your area there are many oak/history forests–now what?
There’s always old-fashioned observation– identify what’s growing in the oak/hickory forests and duplicate it. I’m a little wary of this because a lot of the forests in my area are spoiled by too many invasive species. So I wouldn’t want to waste my time identifying invasive plants.
You might be able to get help identifying plants and trees that naturally co-habit with each other from your state’s native or wild plant society, botany department or cooperative extension program. Or you could try researching it yourself on the Internet. There are a ton of electronic resources available to the public. Try googling “plant communities” along with the name of your state or region and see what comes up.
For example, when I searched for “plant communities” and “Rhode Island,” I found a 21-page PDF file from the Rhode Island Department of Environmental Management called A Natural Community Classification of Rhode Island. It was exactly what I wanted. It lists all of Rhode Island’s natural communities and sub-communities, regardless of their size and significance.
Here’s the description of the oak/hickory forest that I was looking for:
Oak – Hickory Forest. A deciduous forest community on well-drained soils of ridgetops and upper slopes. Soils are usually loams/sandy loams. This type is broadly defined with several regional and edaphic variants. Dominant trees include one or more of the following oaks: white (Quercus alba), scarlet (Q. coccinea), black (Q. velutina), and red (Q. rubra). Represented in lower densities are pignut hickory (Carya glabra), shagbark hickory (C. ovata), and mockernut hickory (C. tomentosa). Other associated trees include white ash (Fraxinus americana), red maple (Acer rubrum), and white pine (Pinus strobus). A tall shrub subcanopy is typically present with saplings of the canopy trees along with witch hazel (Hamamelis virginiana) and flowering dogwood (Cornus florida). Common low shrubs are blueberries (Vaccinium pallidum and V. angustifolium), black huckleberry (Gaylussacia baccata), and sheep laurel (Kalmia angustifolia). Characteristics plants in the herb layer are wild sarsaparilla (Aralia nudicaulis), false Solomon’s seal (Smilacina racemosa), and a sedge (Carex pensylvanica). The American chestnut (Castanea dentata) was formerly a co-dominant canopy tree species in this community prior to the infestation of chestnut blight; today chestnut sprouts remain common in the understory.
Voila! Suddenly planning your ecological garden is much easier. You obviously don’t have to plant all of these species, but you can pick at least one for each layer–a high canopy tree, a low canopy tree, high and low shrubs, and ground covers or the herb layer.
This was something that’s bothered me for a long time…thanks to Toby Hemenway’s Gaia’s Garden: A Guide to Home-Scale Permaculture for letting me in on this trick, as well as opening my eyes to many other gardening possibilities, many of which I hope to explore here in the coming months.
Photo of second-growth oak-hickory forest courtesy of Case Western Reserve University.