Planting Hundreds of Trees
Gardens of Eden is planting hundreds of trees for our very enthusiastic clients. Since we specialize in edible installations that persevere for the long term, tree selection is the cornerstone of many of our designs.
One may hardly need to justify one's desire to want to plant hundreds of trees, as the benefits and synergies are innumerable. Of course, if trees were only providing edible fruit or nut crop in our food forest it would be enough. However there are many other functions of trees which justify their prodigious use in the landscape, including for windbreak, privacy screening, shading and the micro-climate even a small number of trees can produce. Trees can provide forage for livestock and wildlife (ex. mulberries), some fix nitrogen in the soil (ex. redbuds), and provide raw materials for basketry (ex. willows), and fence posts (ex. locusts). Many trees have medicinal leaves, flowers, seeds, and bark. Some trees have different sexes on each individual tree (botanists call this dioecious), so one might need to plant a few "male" pollen-producing versions of a tree nearby in order to produce fruits on the "female" ovary-producing trees (for example, hollies and persimmons are like this). In the same vein, many trees produce both pollen and ovaries, but still require cross-pollination from individuals wit different genetics or different varieties to significantly produce fruit, so planting a diversity of varieties near each other may be necessary (many apples are like this). You may want to plant a tree just because you like how it looks, or because you believe in the intrinsic value of having trees around. Whatever your reasoning for wanting to plant the trees, we’re here to support your desires!
There are many ways to establish desirable trees in your food forest: starting from seed, planting a bare-root sapling, transplanting a larger more established tree, or grafting onto an existing tree. In this post we tackle the very popular option of planting an established tree growing in a container or contained as "ball and burlap."
Time and Space
“The best time to plant a tree was 30 years ago,” and as the old adage states, “the second best time is today.” This is especially true, actually today, in this late winter/early spring thaw. Optimal timing for tree planting is early spring when the soil has thawed and has a high moisture content (but not saturated), before the tree has broken dormancy. There is a reason most of our local nursery suppliers are getting big deliveries of woody specimens this time of year. Reason being is most trees are still in dormancy. It’s best to plant most trees before bud-break in early spring to reduce transplant stress.
Roots have a lot of jobs to do for a tree, not limited to: anchoring the tree in place, absorbing water and nutrients from the soil, transporting water and nutrients up to the trunk of the tree, altering the soil chemistry around the tree. A tree needs time after planting to establish new very fine roots and root hairs that extend out from the larger roots which are essential for performing all these functions. These fine root hairs also integrate with underground networks of fungal mycelium which funnel water and nutrients from beyond root system. By sending out sugary exudates, tree roots make friends with the neighboring mycelium and other root systems. The roots also send out other chemical signals that alter the soil chemistry around the roots (AKA rhizosphere) making it more conducive for growth. It’s more difficult for trees to do all this work toward becoming established while they are simultaneously trying to push out new leaves and flowers! Because most trees do most of their growing in the spring, roots will need to grow a bit earlier to assist with this fresh spring growth.
While transplanting of trees can occur during leaf out, it is much more susceptible to water stress during this time. A tree undergoing water stress is also more susceptible to other diseases and insects. Just like us, trees need proper hydration to maintain a healthy immune system. So, since the time is optimal, lets get planting!
When planning out the placement of your trees, make sure to leave appropriate space between trees to allow them to reach their mature height and spread without running into other trees or structures. Don’t plant a tree too close to a house or shed or you risk damaging the foundation of either. Planting trees too closely together will result in crossing branches and competition for light and other resources.
One exception to this is if you are using a nurse tree: Nurse trees provide protection, such as shelter from wind, shade and structure for a slower growing tree. For example, red-bud could be used as a nurse tree as it is also a nitrogen fixing species, planted just adjacent to another tree. Another exception is if you are planting to form a hedgerow. In this example, trees are planted extremely close together, and managed with heavy pruning to form a “living fence” of sorts.
Digging the holes
Let’s not re-invent the wheel here. There is literally a wiki how on how to dig a hole.
Get those holes dug by any means necessary, using a shovel, pick/mattock, hori hori, rock bar, post hole digger, powered soil auger, excavator, or if necessary, using your bare hands. Bribe a dog. Hire your neighbor.
There are a couple important things to consider before digging a hole:
First, especially if you’re in an urban or suburban area, there may be underground infrastructure that could be damaged by digging. Call 811 to consult your local municipality. This is a free service and they will send folks out armed with cans of spray paint to mark the location of any underground electric, phone, gas, or water lines that may be in your work area. Besides potentially running into underground infrastructure, don’t be surprised if your hole contains lots of rocks, old bricks, trash, pieces of asphalt, dog toys, (etc.) You may be lucky and could find buried treasure.
Secondly, get a plan for what you will do with your extra soil and any neat treasure (rocks, bricks, etc) you might find. You may opt to lay out a tarp to put soil on to and drag to a different location. You may know of a low spot that could use a little fill. Remember that dog you bribed to help you dig that hole? Yea maybe that’s fido over there doing overtime near your hostas.
Once you’re digging, It’s a good time to take a look at the quality of the soil in your hole. Take note of how the color, texture, density and moisture in your hole changes as you dig deeper. Is the soil dark and soft, easy to dig into? Is it sandy? Full of pure clay? Are there different layers of soil in your hole? There are likely distinct layers of soil that vary in texture and color as you dig further than 6 inches deep. These are known as soil “horizons” and can tell you a little bit more about what’s going on in the earthen underworld.
Don’t miss this opportunity to take a close look at what is going on. Typically, soils are darker near the surface where it is made up of more organic matter, and lighter in color and made up of more inorganic minerals deeper in the ground. A layer of very grey clay or extremely dark and squishy soil could mean that area is saturated with water for a significant portion of time, and may guide you to plant a water-loving tree in that place such as an elderberry, willow, or silky dogwood
Its important to plant your tree at the appropriate depth in the ground. Not too high, not too low, but just right. Planting too deep will suffocate roots, while planting too high will cause root stress from exposure to more extreme swings of temperature and moisture. The base of the tree, right at the root flare, should be just at the level of the surrounding soil. You can use a stick or tool handle to lay across the hole to help determine the depth of the hole. The bottom of the hole should be the native undisturbed surface, or packed down well, to prevent your tree from sinking deeper over time as the dirt settles.
You're gonna want your hole to be about 2-3 times as wide as the width of your transplant’s root-ball. If you are going to amend the soil, this will provide a nice growing medium for new roots to venture into. This also gives you room to properly pack the soil back in around your roots.
Place the tree in the hole (at appropriate depth) and secure the tree in a proper position with trunk upright and plumb in all directions. Its helpful to recruit a planting buddy or two for that process. Delicately and with utmost love and care, using a very sharp knife or pruners, slash violently through the root ball on at least 2 sides, especially if the tree has circling roots along the outside from being container-bound. The roots will grow out from the cut locations into the surrounding soil Without injuring the roots the circling roots may continue to circle and get larger, eventually potentially girdling/strangling the tree.
Filling the hole back in
If your soil is clayey, as is often the case in the Southeast US, be sure to use plenty of that native clay in the soil mix you put back in the ground. In fact, it is entirely okay to use only native soil to re-fill the hole. If the walls of your hole are very heavy with clay, and you fill the hole back in with loose fluffy organic soil, you risk creating a bathtub effect where water is unable to drain from the bottom your hole and soil mix fills up with water, resulting in waterlogged roots. In addition, you may end up with more circling roots inside your hole, as if it were still growing in a plastic pot! It’s common practice to thoroughly incorporate some amount of soil amendments into your primarily native soil back-fill. However, it’s important to use amendments sparingly enough to match the surrounding soil texture, and focus more on improving the environment around your newly planted tree to support good overall soil health with proper mulch and companion planting.
Then begin filling the hole in with the remaining soil, taking the time to pack the soil in firmly in the soil around the roots every few inches or so to eliminate air gaps. This firm packing is important for root development and to help the tree anchor itself in the ground securely. Firmly pack in the soil in layers, until it reaches level of the surrounding ground surface.
The last critical component of filling in the hole is properly applying generous mulch. Lay the mulch 3 inches thick, in a layer that extends out beyond the dripline of the tree. Pull any mulch at least 3-4 inches away from the base of the tree, allowing for the root flare to be fully exposed in that area. DO NOT UNDER ANY CIRCUMSTANCES PILE YOUR MULCH LAYER AGAINST THE TREE TRUNK. This terrible misguided practice is called “volcano mulch” and is a traumatizing thing to witness. I refuse to post this vulgar and disturbing imagery in this blog post, but the curious folks can peruse the wall of shame here.
Mulch will provide many functions: retaining water around the root zone, preventing soil erosion, insulating the soil from extreme heat and cold, suppressing weeds, adding organic matter and nutrients to the soil as the mulch breaks down, provides habitat for beneficial mycelium in the soil, and protects the base of the tree from damaging weed-eaters. Continue to add mulch to the base of your tree as the mulch breaks down to keep optimal conditions near the root zone.
While many trees do just fine without staking, it is recommended for larger trees, trees with an unusually small root system, and trees in areas with strong prevailing wind should be staked in place to prevent toppling over. Stake the tree using soft materials (not wire) in at least 2 directions and be sure to allow the tree some freedom of movement with the wind. The micro-movements of the tree during establishment are important to encourage a strong root system. Be sure to remove the supports before the end of the first growing season, to allow the tree to grow freely, as tree stakes left on too long can hinder growth and in extreme cases can damage the bark.
If you're just up to planting just one tree, don't wait for Arbor Day. Now's the time to start planting! If you want to plant hundreds of trees, you might need a little help, so give us a call and we can get your forest materials sourced, delivered and installed the proper way to ensure longevity and health of the trees. Happy Planting!