Selecting Trees for a Forest Garden: What to plant and How Many
These days, the "new" wisdom is that - 100, 400, 1,000 - "you can't plant too many fruit trees!"
Not surprisingly, this advice most often gets repeated by nursery businesses that sell fruit trees. And as a guy with a small nursery business, sure, I agree with it, but I add a HUGE caveat: it depends on what kind of tree you're planting.
The problem is fruit trees are work.
Work, work, work!
If you buy a bunch of fruit trees, you're buying yourself a bunch of work!
So I break down trees into how much work -time, energy and care - they require to produce a yield: "Intensive" trees, that require a lot of work, "Extensive," which produce fruit with almost no care, and "Semi-Intensive" that are somewhere in the middle.
The important thing here is the "Law of Diminishing Marginal Utility." Up to a point, having more fruit is GREAT!
But after that point, the value of each fruit diminishes as you add more. One apple tree can provide a family with most of the fresh apples they'll eat, plus some for gifts, trade with neighbors and cooking or storing. Having a few apple trees means the family will have to spend some serious time doing orchard work, and probably have to use chemical means to maintain their fruit, but if they work hard they can be completely self-sufficient on fruit. Beyond that, they'll have to put time and energy into an orchard business, or else they'll have a massive mess of rotting apples and wasps, create disease and pest problems for their neighbors. Still more trees? Now you HAVE to use chemicals, manage a labor force, advertise and market your apples, find shipping, purchase insurance for crop failures.... Still MORE? Now there's a glut in the market and each new apple - and the time you spent growing it - is worth less and less.
Looking at historic sources, old-time homesteaders understood this very well! It was the standard recommendation that - unless you wanted to run a full-time orchard - each family had a few fruit trees, depending on what worked best in the region. Beyond that, more fruit meant more work with less and less to show for it! In our region it was common for each family to have a workhorse apple, usually a cooker/keeper, possibly a pear, or maybe a cherry or two. A few berry bushes rounded out the homestead fruit selection. This was the standard in England, too, where allotments and cottage gardens typically had a plum or cooking apple like the Bramley. Actually, this pattern looks very similar world wide.
But not all fruit and nut trees are equal in this regard. Some take more work than others. So, while a few too many "INTENSIVE" trees, like apples, can become a menace, it really is almost impossible to have too many "EXTENSIVE" trees like service berries. They produce wonderful fruit that's rarely buggy with almost no work. And if you don't harvest them, the birds will, so you won't end up with a stinky rotting mound of wasp food making the neighbors mad.
Keeping this in mind, a well-planned homestead will "bulk up" on "extensive" trees that will provide great benefits but won't become a burden, and have just a few, well-chosen "intensive" trees.
After reviewing historic and modern recommendations, here's how I'd break these down:
Intensive Fruit Trees (my recommendation, 0 - 2 per family, unless you're operating a pro orchard.)
First, you'll notice that I expanded beyond trees to include all fruiting woody perennials, because they'll give you fruit and add to your work, just like a tree! So, it's good to consider them together.
Only plant these if you really love the fruit and you're going to make a commitment to work for it. Not to be dogmatic or anything, but for most homes and home-owners they're more trouble than they're worth. If you really love them, go for it!
But let's face it, there are probably over a dozen apples and half dozen pear trees within a mile of your home that never get picked.
Since forest gardens rely on a no-spray regimen for their health and pest prevention, in the Great Lakes region, plan on bagging fruit from these trees to protect them from pests, by putting paper bags or "wedding favor" bags on the young fruit after pollination. They will also require pruning and other maintenance and may experience disease issues. Generally, I look for varieties selected for "no spray" or organic treatment. I also recommend dwarf varieties to make bagging and picking fruit easier. Apples European pears Plums Peaches Apricots Cherries
Semi-intensive (1- 4)
These options provide big, sweet, valuable fruit without such a problem with bugs. It's possible to get good, clean fruit without spraying or bagging. The biggest work problem with these after establishment is harvesting, and storage, which can become a burden. Asian pears Jujube (zone 7 and up) Nakita's gift persimmon (the only persimmon I can currently recommend for home owners.) Cider and cooking apples and perry pears. (if you don't mind buggy fruit.) Quince (A known fireblight host, Aromatnaya's the only variety I recommend.)
High-value Extensive (Feel free to plant lots of these.) You almost can't plant too many of these. Where it seemed appropriate, I made recommendations to feed a family of 4. Having extra could provide the opportunity for trade, sales, or value-added products without creating a burden. These have almost 0 maintenance requirements and if they're not harvested they won't create a huge mess. Blackberry (Plant in an "island" where it can be maintained by mowing.) Raspberries (same as above.) Goumi ( 4 bushes) Elderberry (edible flowers and fruit.) Serviceberry Hardy kiwi (Issai only variety I recommend, 2 vines) Paw paws (3 - 4 trees) Honeyberry (5-10 bushes) Strawberries (25 plants) Aronia berries Nanking cherry (4-5 bushes) Medlar (1. Beautiful tree!) Mulberry (Illinois Everbearing. 1 tree.) Cornelian Cherry (2 bushes) Hazelnut bushes (look for selected varieties that are blight resistant and have large nuts.
Lower value extensive
These add diversity to a system, but are not highly recommended. Blueberry (valuable fruit, but yields suffer without spraying) Passionfruit Kousa dogwood (selected fruit varieties only, 1-2 trees. Beautiful.) Sasafras Linden (edible leaves) Toon tree (edible leaves) Staghorn sumac (edible "berries" for tea.) Wild cherries
Recommended Nut trees I made nuts their own category. Again, they are generally problem-free, but usually take work to process and store. They're also generally very large and only appropriate for the largest forest gardens. Gardens under an half-acre could look into duel-purpose trees, like Chinese Apricot, which produces an apricot and an almond all in one. Larger that an acre, large nut trees should probably part of your planting. I consider chestnuts particularly valuable for homesteaders and forest gardeners, not to mention cooks!
Black walnut. Valuable tree, difficult nuts to crack. Select easy-to-crack varieties. Carpathian walnuts. Pecans. Butternut. Heartnut. Hickory nuts. My favorites. Chestnuts. Staple carb crop highly recommended for larger gardens or forest systems. Korean pine. Monkey puzzle tree. Generally too large and slow-to-mature to recommend for forest gardens. But very valuable future crop.
What does it all mean?!?!
Well, putting that altogether, what would my recommendations for a tree planting look like? Let's start with a typical suburban lot between 1/10th of an acre and 1/4 of an acre. 1 clump of 3 paw paws. 2 Asian pears. 1 mulberry, Nakita's gift persimmon or medlar MAYBE 1 dwarf multi-graft apple or other intensive fruit tree. 5 or 6 "extensive" fruit bushes.
That collection would look very much like the 1/10th acre Holyoke Edible Forest Garden, one of the most famous forest gardens in America. It's interesting to note that a few years ago they blogged about removing all their "Intensive" fruits like apples and cherries, saying "it's not worth it!" and replaced them with asian pears, paw paws and persimmons.
With more land, I might add a few more "intensive" or "semi-intensive" trees, but mostly, I'd look to add more "extensives." Over a half-acre I would probably add large nut tree or two, and I'd fill in the understory with appropriate shade tolerant "extensives" like paw paw, elder and serviceberry.
Much beyond an acre, or possibly a few acres, we've really outgrown the idea of a "forest garden" and into the concepts of "managed forest," "agriforest systems" or Permaculture orchards. At that scale, keeping in mind the Permaculture concept of "zones," I would create a small garden just as above, and then for the rest of the land, I'd look to create a commercial orchard of some kind or an extensive forest of "extensive" fruit and nut trees with high-value wood.
Again, this arrangement describes and reflects much of the historical practices of land management prior to the age where fossil energy transformed our landscapes by making environmentally degrading practices cheap and easy. What worked well for people in the days prior to cheap energy is likely to work well for those of us who wish to lower our environmental impact, save money, and grow our food organically.
And remember, Permaculture starts with the ethic "people care," so if your planting creates a bunch of work for you, it's' not "people care," and it's not Permaculture!