Growing a Forest in your Backyard (2024)

• By Cathy Caldwell
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• September 2021-Vol.7, No.9

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• 3 Comments

Creating a backyard forest is fast becoming “a thing” — for a number of reasons. There’s the hope that adding lots of trees will have a mitigating effect on global warming. And I’d be willing to bet that another motivation is Doug Tallamy’s vision of an immense “Homegrown National Park” consisting of a continent-full of backyards filled with native trees, shrubs and perennials providing much-needed habitat for insects, birds, and other wildlife. You’ve probably read last month’s article, “Gardening to Save the Planet,” which explores Tallamy’s ideas about restoring lost habitat; if not, you’ll definitely want to do so.

If you do a little online Googling on the subject of creating a backyard forest, you will quickly discover two early visionaries of the backyard forest movement: Akira Miyawaki and Shubhendu Sharma. Miyawaki is a botanist who went to India to test his idea that a depleted landscape could be transformed into a forest in a relatively short time by first remediating soil compaction and then by planting closely-spaced seedlings of “potential natural vegetation,” i.e., the plants which would naturally occur in that particular place. Sharma, an industrial engineer, volunteered to help with Miyawaki’s experiment, and is now the head of a for-profit company called Afforestt, which provides forest-creation services. To find out more about the work of Miyawaki and Sharma, you may want to watch a TedTalk or two: Shubhendu Sharma: How to Grow a Tiny Forest Anywhere(2014) and How to Grow a Forest in Your Backyard(2016).

The Miyawaki method does not appear to have been widely adopted in the U.S. or other temperate regions, though some experimentation with the method has been conducted in the Netherlands and in England. See Tiny Forest Zaanstadand “First Tiny Forest Being Planted in UK,” The Ecologist.org. Miyawaki’s ultra-close spacing of seedlings runs counter to the prescribed methodology of forestry scientists in the U.S., but it may yet be adapted or adopted here, though the tight spacing may already have become less viable in our warming climate.

One thing I discovered in working on this article is the shear amount of research being conducted on forest ecology and its interaction with the warming of the planet. For example, scientists are looking at ways to make plants more drought-resilient. The role of fungi in enhancing a plant’s drought tolerance is the focus of major research. For example, some strains of the most common ectomycorrhizal fungus, Cenococcum geophilum, has been found to assist host trees in resisting drought stress. Scientists involved in this research believe that additional study of the genomics of this fungus “should facilitate the identification of drought-adapted C. geophilum strains, which can be used to efficiently support their host trees threatened by the forecasted increase in drought periods in many parts of the world.” See “How fungi help trees tolerate drought,” Science Daily(2016).

If you’re interested in growing a backyard forest, you are probably familiar with the benefits of adding trees to your yard. The list of benefits is long:

• Plant a few treesand add a few more every year. This is not the quick way to develop a forest, but it will work just fine. Just be sure to remove enough turfgrass and weeds around your new tree so that its roots have ample room to grow — 2 or 3 feet is best; you don’t want your tree to have to compete with the grass roots for water and nutrients. Mulching all around the tree (except right next to the trunk) will be even more important in the hot, dry times ahead.
• Create planting bedsfor new trees, using a grass-smothering technique like sheet mulchingor solarizing, and then plant new trees into the mulch. This kind of bed prep takes four to six months at least. For guidance on sheet mulching (a/k/a lasagna gardening), read Lasagna Mulchingfrom the September 2020 issue of The Garden Shed. Solarizing involves covering the grass with plastic, which basically “cooks” the grass and some weed seeds. For details on soil solarization, see “Soil Solarization for Gardens and Landscapes,” Univ. of California Cooperative Extension, ucanr.edu/sites/Solarization. Having employed the solarization method once, I’m not inclined to do it again because of the amount of plastic involved. As an alternative to plastic, you can smother your turfgrass with some variation on sheet mulching — such as a 6-inch-layer of wood chips, 4-by-8 pieces of plywood, or a layer of newspapers 20 sheets thick with wood chips on top.
• Stop mowing. This no-mow method works well if your lawn isn’t compacted and there are plenty of native trees around dropping seeds. Basically, you’re sitting back and letting natural succession create a forest. If you have tree seedlings popping up here and there in your yard, it’s probably a good candidate for this method. Once you have seedlings coming up, you’ll nurture them with mulch, watering, and weeding. To make this method more pleasing to the eye, plant some native wildflowers along the edges, at least until your forest gets rolling.
• Convert grass to a cover crop like clover or rye, and plant trees through the cover crop. For more information about this method, see Building a Backyard Forest/Maryland Dept.Natural Resources, which is well worth a careful review as it contains lots of helpful information as well as design templates and plant lists to help you choose the right trees and shrubs for your soil and exposure.

Some of these methods involve preparation that can take months, even a year or more. I have a sheet mulching operation going on in my yard right now that will take six months. Last spring I layered mulch, newspaper, cardboard, leaves and some kitchen wastes onto two island-shaped sections of lawn. My goal is to plant native trees and maybe a few shrubs in each island bed this fall. By that time, the turfgrass will have been killed and the soil improved, thanks to the “cold composting” of the leaves and other ingredients that I added. For more about “sheet mulching” and “cold composting,” see theLasagna Mulchingarticle inThe Garden Shed.

No matter what method you use, weeding and removing invasives will be essential — at least for the first several years — for your forest to thrive. Get familiar with the appearance of the common invasives at the seedling stage so you can remove them early. For help in identifying invasives, refer to Blue Ridge PRISM Invasive Fact Sheets. After your forest has a canopy, it will shade out most weeds, and the forest floor will be covered with leaves, which will discourage most invaders.

Choosing Trees for your Backyard Forest

The best trees for your site will depend upon your soil and the sun exposure in your yard. If you’re not already familiar with these features, you’ll need to do a bit of homework. You’ll no doubt want to eventually have several kinds of native trees and native shrubs, and probably native ground covers like ferns. At least one kind of oak is a must if your yard is to be part of Tallamy’s Homegrown National Park.As you consider which type of oak will suit your site, keep in mind that all oaks will do well in rich, well-drained soil, but if you have thin or dry soils, scarlet oaks and white oaks are usually the best choice.

There are several excellent sources for choosing native trees well-suited to your site:

• Virginia Native Plant Finder (an interactive site that allows you to plug in variables)
• Right Tree-Right Place Tree List/Tree Stewards(comprehensive and local)
• Piedmont Natives Plant Database/Albemarle County.org (searchable)

For excellent guidance on tree-planting generally, see the Tree Planting Guide/Charlottesville Area Tree Stewards.

Starting with Seedlings

If you have a large yard and intend to plant more than a few trees, you may want to try the inexpensive bare-root seedlings sold by the Virginia State Forestry Nurseries. For just $2.00, you can buy a white oak seedling! Admittedly, it will be a tiny seedling. The seedlings are either one, two, or three years old, andseedling age is indicated with 1-0, 2-0 and 3-0. The Crimora nursery opens for business in October, and you can buy in person or order online for shipping to your home. Be sure to order in October or soon thereafter for best selection. I recently got in touch with the nursery staff, and was advised that shipping and picking up for 2022 will begin on February 22nd. Early spring is the recommended time for planting these little seedlings so that they will still be dormant when planted.

Bare-root seedlings start small but within just a few years they will catch up with larger-sized trees planted at the same time. You will need to protect the seedlings from deer, mowers, and weed-eaters for several years with shelters or fencing. For information on tree shelters, see the recent Garden Shed article “Deer, Deer, Deer!

Before you even order tree seedlings, figure out how you plan to proceed once you have the seedlings in hand. It’s essential that you be ready to plant them immediately — as in within 24 hours — though it’s possible to store them for a few days in the right conditions. You’ll want to have your planting site well-prepared, the soil tested, and ready to go by this fall. Have ready the deer guards you plan to use, whether tree tubes or wire mesh tree shelters. For a discussion of the types of guards available and how to use them, see How to Manage Deer Damage on Trees and Other Plants,” Univ.Minn.Ext/Netting, Tubes or Other Protective Structures.

Because bare-root tree seedlings are generally employed in large-scale forestry operations, the planting advice is usually oriented accordingly. But you can proceed as you would with any tree — basically, digging a hole large enough to generously accommodate the root system, backfilling soil around the roots, and keeping the root collar at the soil line. For more detail, including illustrations, check out the Forestry Department’s Hardwood Planting Guide. If you are planting a lot of seedlings in a large area, you may want to follow the procedure for large scale plantings, as demonstrated in “Planting Bare-root Tree Seedlings in Spring,” Penn State Ext., and the accompanying video.

Perhaps you want to create a food forest, which combines edible plants with trees. For an inspiring “big picture” look at forest gardening, watch this short film produced by National Geographic: A Forest Garden With 500 Edible Plants Could Lead to a Sustainable Future. Another source of inspiration is a food forest at George Mason University. In 2012, George Mason embarked on a project to turn a grass lawn on the campus into a food forest employing principles of permaculture. By 2017, the project — called The Innovation Food Forest — was flourishing. According to its website,

“Permaculture strives to create a closed loop environment where the outputs for one process become the resources for another. In nature there is no such thing as “waste.” The concepts of permaculture are integrated into this space: earth care (taking care of, and restoring, the planet and its resources), people care (providing for food, community, and interactions with nature), and fair share (distributing excess resources).”

— Innovation Food Forest, George Mason University

The former grass lawn at George Mason now features native trees and many fruit-bearing shrubs and plants, including sassafras, pawpaw, redbud, American hazelnut, persimmon, fig, highbush blueberry, elderberry, raspberry, and many others. You’ll want to take a look at the Innovation Food Forest website to see plenty of photos and their plant list.

For a detailed webinar focused on design principles which apply to creation of a food forest in a typical backyard, watch this video: “How to Design a Backyard Food Forest with Permaculture Principles,” www.youtube/Utah State Univ. Extension, Even though most of the plants discussed were suited to Utah, there’s other helpful content, including design principles and drawings. And be sure to read the recent Garden Shed article,Growing Fruits and Vegetables in Your Backyard Forest. If you want to dig really deep on this subject, Oregon State offers an online college-level course: Permaculture Food Forests 101.

SOURCES:

“Trees Please! And Make Mine a Native!”Plant Virginia Natives.org

The Woods in Your Backyard: Learning to Create and Enhance Natural Areas Around Your Home. Jonathan Kay, 2016. (VCE Pub./ANR-199) (a video about this book is available atVa.Coop.Ext.Publications & Educational Resources, and the book itself is available from the Cornell online bookstore,Cornell Store.com)

“The Woods in Your Backyard Workbook”Va.Tech.edu

“Book Review: The Woods in Your Backyard,” Ecolandscaping.org

“Forests and Climate Change: ‘We Can’t Plant Our Way Out of the Climate Crisis,'” University of Michigan News

“The Miyawaki Method: A Better Way to Build Forests?” JSTOR (2019)

“From Turf to Trees: Converting Lawn to Forest,” Univ. of Maryland Ext

“The surprising plant-fungi relationship that could help feed us, even as the world heats up,” Ideas.Ted.com (2017)

“Learn to Grow a Food Forest in your Backyard,” NC State Ext.

“Forest Farming,”Va.Coop.Ext.

“Landscape Trees and Climate Change,” Utah State Univ.Forestry Ext(May 2021)

“From Turf to Trees: Converting Lawn to Forest,” Univ. of Maryland Ext Video.

“The Growing Challenge of Vegetation Change,” Science(May 2021) (Some “forests have experienced extensive tree loss . . . largely because of hotter and drier climate extremes. Forest disturbance driven by aridity, heat, fire, disease, pests, and wind creates opportunity for vegetation change. At the same time, climate change shifts conditions to favor different plant species across the landscape.”)

Afforestation: An Overview,”ScienceDirect.com

Planting a New Tree, The Garden Shed (Nov. 2015)

“Planting and Care of Tree Seedlings,”Univ.New Hampsire Ext.

“Tree Seedling Planting Guide,” Utah State Forestry Extension

“Planting Bare Root Seedlings,” Seeds to Trees.org.