(Perma)Culture and Sanity
Don't let your newly-arrived trees' roots dry out, especially if they are bare-rooted. If plants are to be stored for more than 2-3 days, 'heel them in' by digging a hole and burying the plants' roots in damp soil or sand, with the plants themselves leaning at a 45-degree angle to encourage continued dormancy (they can also be potted into containers, but this is less desirable because of root cramping and limited nutrients in containers).
When you are ready to plant your trees, water them thoroughly a few hours ahead of time if in containers. If bare-rooted, place the trees in a 5-gallon bucket of water a few hours before planting, and make sure all roots are submerged up until the moment they are planted. Some compost added to the water can help by innoculating the trees' roots with their essential fungal associates.
For each tree dig a hole deep and wide enough to accomodate the tree's roots spread out. Pile the soil from the hole into a wheelbarrow, or on a tarp or piece of plywood next to the hole.
To refill the hole you'll use the original dirt mixed with rock amendments, but don't mix organic materials into the soil going back into the hole. Experiments have shown that organic matter mixed into the planting hole can make your tree think it's in a container, resulting in roots which circle in the good soil instead of spreading into the surrounding, often-poor soil. Organic nutrients can be applied as a mulch after the tree is planted.
Rock-based amendments can include 1/4 cup rock phosphate or ½c bone meal, ½c gypsum per tree hole (unless you're in limestone or caliche soils; these soils don't need these additions).
Before placing the tree into the hole (making sure the original soil line on its trunk is exactly where the new soil level will be or a tiny bit lower), walk around the tree and find the direction it 'thinks South is.' Most of the leaves will be facing their flat sides toward this direction. It's usually obvious—even if the tree has no leaves, by walking around the tree you will usually notice it facing in a particular direction.
Taking note of which way the tree naturally faces will allow you to plant the tree facing the same way it grew originally. This gives the tree the advantage of being able to collect as much light as possible right from the start, without having to waste any energy turning its leaves and structure toward the direction of light in its new home.
Make a cone of the rock powder-amended soil in the bottom of the planting hole, tall enough to accomodate the tree's roots. Now (with the tree facing toward the sun as it grew originally) place the tree in the hole. Carefully spread the roots out evenly in all directions over the cone of soil in the hole. The cone should be high enough to reach to the bottom of the tree's trunk, with the tree's original soil line even with the surrounding ground.
After each tree is placed in its hole at the right height, with roots spread and branches facing south, refill each hole about half full with the soil that came from the hole (ideally improved with rock-powders if phosphorous, calcium or potassium are lacking). Carefully work soil around the roots, lightly packing the soil with your extended fingers to remove air pockets.
When the hole is half-filled with soil packed carefully around the tree's roots, fill the hole with water. Gently jiggle the tree to settle the soil, dislodge air bubbles and to orient the tree straight up-and-down. Let the water soak in, then fill the hole again with water. Repeat the watering for 3 or 4 fillings (letting the water soak in completely each time), then finish filling the hole with the rest of the original soil.
Use the last bit of soil to make a temporary ring—or a 'boomerang' on slopes, concave toward the uphill side to catch runoff—around the tree's base to hold ~10+ gallons of water. Then fill the watering ring or boomerang with water again and let it soak in completely. These waterings will provide your newly-planted tree with a substantial reservoir of water from which to draw, and will help ensure that your tree's vulnerable roots do not have the moisture sucked out of them by dry surrounding soil.
Deep soaking at planting time is very important—many trees start dying as soon as they are planted, because the planting hole was not soaked thoroughly and deeply enough and the tree's roots were dessicated by the surrounding soil.
Apply organic amendments as mulches on the soil's surface, preferably placing a thin layer of finished compost directly against the soil under the rougher materials. Don't pile straw or deep mulch right against small tree trunks—meadow voles will take advantage of the mulch's cover to chew the tree's bark.
Use horticultural whitewash, or paper or plastic tree wrap, on young tree trunks to prevent early budding or 'sunburn' damage ('sunburn' is a misnomer with trees—it is actually frost-damage caused to newly-wakening inner bark). Plastic tree guards are tough, and also help to protect young trees from being chewed on by rabbits and rodents.
Tie trees in three directions for a couple of years to keep their new roots from being torn in the wind. Tie trees slightly-loosely during the first year (couple inches of play in each direction), then loosen to 4 inches or so of slack in each direction during their second season (use cotton clothesline rope and tie loosely around trunks). Remove ties after the second season, while the tree is dormant if deciduous.
Tiny windbreaks are a very good idea for newly-planted trees—using rocks adds the benefit of heat mitigation and storage (i.e., frost protection). All trees should be dished for watering though tiny trees might hold only 5 or so gallons (start larger—dishes will quickly get smaller after you've made them, because of settling). Small, shallow water-diversion ditches can gently lead occasional runoff water to shallow tree planting basins.Water Trees for a Year or Two Until They Establish
It's best to plan on supplying your newly-planted trees with drip irrigation for a couple years after planting, to ensure their survival and get them firmly established. 'Drip irrigation' can be as simple as moving the end of a dripping hose or a more complex (and expensive) system, but the point is to let the water slowly (so none runs off and is wasted) soak deeply into the ground so that all the roots deep in the hole get watered at least every week or two if soaking rains don't take care of the watering. One deep soaking every week is far better than shallow watering every day.
Reprinted from (Perma) Culture and Sanity Website