by Melinda Heigel, EMGV Intern

When you hear the term gravel gardening what do you envision? A scorching hot parking median filled with river rock and a few struggling trees? A sparse desert landscape devoid of anything lush and showcasing only the prickliest of plants? Well think again. Gravel gardening (also known as scree or dry gardening) offers so much more. You will now find gravel-type gardens starting to pop up at some of the world’s most beloved botanical gardens—including Chanticleer and our own NCSU’s J.C. Raulston Arboretum and Duke’s Sarah P. Duke Gardens. Juniper Level Botanic Garden in Raleigh has also adopted and amended this method with its very own crevice garden, substituting gravel with 100 percent PermaTill®, a pea gravel-like product made of slate found in North Carolina. Gardening with gravel and other hardscape materials offers a sustainable, lower-maintenance option that doesn’t sacrifice beauty. Legendary English gardener Beth Chatto, a pioneer of this style of gardening, described this type of method succinctly when she said, “This garden was not to be irrigated in times of drought. Once established, the plants must fend for themselves or die.”

So if gravel gardening is good for the environment and good the gardener, what is it exactly? Typically, gravel gardening involves putting in some upfront work. It means creating a garden bed 4-5 inches deep with gravel laid directly on top of soil. The gravel should be uniform in size and can vary from pea gravel to ¼ inch and must be igneous or metamorphic rock, so it won’t break down over time. Typically, gardeners use their existing soil without amendments (J.C. Raulston has turned PermaTill® into their scree garden), and good drainage is a must.  Equally important in the design is an even thickness of gravel throughout—especially out toward the edges. More shallow areas of gravel only invite weeds. To achieve this, a good gravel garden should have a border 4-5 inches in height.  Bricks, metal edging, or even rocks are all options; you could even make the gravel garden a raised bed.  Gravel acts like mulch here: it suppresses weeds and means very low maintenance in the future. When preparing a site with gravel for this method of gardening all existing plant material should be cleared prior to planting.

Gravel gardens are intended to be in sunny, hot, and dry locations. Drought tolerant plants are the right choice for these hardy gardens.  While gardeners should plan to do a good deal of watering the first year while the plants’ roots are getting well established, this diligence will pay off.  This method’s water-wise and low-maintenance features really come into play in subsequent years as plants should require no supplemental irrigation thereafter. If properly prepped at installation and their spent plant material cut back well each spring, these gardens are devoid of many weeds and easy to maintain once they grow in.

In terms of garden design, many gardens grasses like our native Muhlenbergia capillaris (pink Mully Grass), Schizachyrium scoparium (Little Bluestem), and Nasella tenuissima (Mexican Feather Grass) make excellent backdrops for gravel gardens and offer great fall color and wintertime architectural interest. And while cool Cacti, Yucca, Agave and types of Euphorbia work quite well, options abound, including many natives. Some good choices for gravel gardens in our area also include the following:

At once earth friendly and gardener friendly, this low maintenance method could be a great addition to your garden repertoire.

Further Reading and Additional Photos of Mature Gravel Gardens

Gravel Garden Ideas from Chanticleer

Beth Chatto’s Gravel Garden

Gravel Gardening: The Planting Formula to Success (Scott Arboretum)

By Peter Gilmer, EMGV

I recently heard the term wolf tree, and wondered what in the world that could mean. I have since learned the meaning of the term and the significance of these trees, and have discovered that we have one on our property in northern Durham county.

When settlers from Europe came to this country, they felt the forest was in their way. They were used to open fields, grazing animals and plowed soils. As they took over and cleared land, a few trees would be saved to shade the farm animals and produce nuts for the squirrels. Without the usual competition from neighboring trees common in a forest setting, the lone trees would send branches out laterally to to expose their leaves to the sun, rather than having to grow quickly towards the sky. The lower limbs of a wolf tree would not become senescent due to the shade of neighboring trees and the profile of the tree would be very different from the same species growing in the forest.

When I first saw the wolf white oak on our property, I thought something was wrong with it and that it might be dying. The main trunk was short, maybe 15 feet, and there were too many branches, some nearly horizontal. I have learned that this is common for a solo tree in a pasture setting. If the pasture is abandoned, new trees will grow but the wolf tree might have a 100 year head start, so it retains its branching habit. Our tree is easily seen in Google Earth images, surrounded now by evergreens, mostly pine and some cedar. The pasture is no longer recognizable.

Wolf trees can be quite old. I measured the circumference of ours to be 14’ 9” at chest height, and using the tree age calculator, this tree started life in about 1740! That is amazing. Decades before the American Revolution. Beneath this tree, not seen well on the photograph, is a low stone wall surrounding an abandoned Cemetary. There are seven grave stones, and some are legible, dating to the 1850s. The tree would have been ~100 years old at the time, and the loan tree on the edge of the pasture was a perfect place for the grave site.

The term wolf tree may have originated from the appearance of the tree surrounded by much younger trees, like a lone wolf surrounded by other animals who are protecting themselves from being singled out for the kill.

These trees were once thought to be problematic from a forestry standpoint. Their multiple low branches meant that there were not long stretches of available wood for harvest, where as the same tree in a forest setting might have 60+ feet of trunk. The trees were thought to use up a disproportionate amount of nutrients, and removal was recommended in older forestry texts. It is now known that these trees actually provide significant habitat for birds, reptiles, insects, and mammals, ecological services that far exceed those provided by forest trees in a per tree comparison. These giants are to be treasured. I wonder how many this old still remain in Durham County.

*Further Reading*

Wolf Trees: Elders of the Eastern Forest (American Forests)

Defining out Landscapes: What is a Wolf Tree? (Heritage Conservancy)

Wolf Trees Provide Insight into the History of Our Land (MSU Extension)