Mountain Planting Instructions
1) In moist (never wet) soil, dig a hole at least 2-3 times as wide as, and no deeper than, the pot or root-ball of your tree. Most plants should be planted with the top of the roots (the root-flare of the trunk) slightly above the level of the surrounding soil (grade). Large trees can be planted 3-4” above grade. Remove large rocks and store the loosened native soil to one side.
2) Carefully pull the pot off the root-ball and install a root-guard before sliding the roots into the hole. Orient the lowest branches to the southwest (providing shade for the trunk). Deciduous trees benefit by having some of the periphery of the root-ball shaved off (~15% of the circumference, ~1/2” deep off the outer edge – top to bottom) with a knife, hoe, or shovel. Don’t disturb the roots of native evergreens. Staking may be done now with one (1) sturdy 2” lodgepole stake just outside the root-ball on the southwest side of the tree (shade for the trunk and support against prevailing winds).
3) For #15 and larger pots, backfill the bottom 1/3 to 1/2 of the hole around the root ball with only loosened native soil. Do not stamp or compact the soil. You want at least 12″ of amended soil in the upper half of the backfill (this mimics a healthy soil profile) so you use ALL amended soil when planting #7 and smaller.
4) If the tree is balled in burlap (“B&B”) cut off all burlap, twine and wire from the upper half of the root ball and trunk at this time. This is VITAL.
The Backfill Soil Blend is ≥ ½ native soil mixed with ≤ ½ mature, finished compost like Kellogg’s Gromulch, (add pre-hydrated water-holding gel. ) with organic slow-release fertilizers (G&B and Biosol). Lime should be incorporated into the soil for calcicole plants like lilac, lavender, delphinium and peony.
5) Continue to backfill with a soil compost blend. Using biologically active mature composts is beneficial, if not essential. Sierra snowpack recompresses our mineral soils that have been merely turned. Amendments help soils resist compaction, retain moisture and nutrients, maintain aeration, and encourage beneficial soil organisms. Mixing compost with soil creates a progression from the very coarse container medium to the fine textured native soil.
6) Mulch – Spread 2-3” (4-5 is even better) of loose compost, bark or wood chips from the outside edge of the root ball to far out past the drip-line of the new tree. This is essential. The hard working and very shallow roots only function effectively when protected with a blanket of mulch. An average large pine, for example, has 90-95% of its roots in the top 12-18″ of soil in a root pan at least as wide as the tree is tall. Our extremely dry, fine-textured, flour-like soils are exposed to intense sun, low humidity and desiccating winds. The bone-dry soils many feet from your newly planted trees and shrubs is wicking-away any moisture that you put into the ground. The broader and thicker you mulch, the less you have to water and the faster your plants will grow.
Also, we add organic matter to loosen and improve the aeration (gas exchange) and drainage for the roots and beneficial microorganisms associating with our plants. Over a very short time, that compost breaks down and the soil can return to their poor-draining, low aeration state UNLESS we have a source to replenish that organic material: a thick layer of mulch on top of the soil. Note: mulch that is lightly irrigated promotes the growth of beneficial fungi that aid in its decomposition. Fungal mycelium has been shown to be strongly fire retardant.
Rule-of-thumb: NO bare dirt in a diameter equal to the height of the tree. – or – “Dig the hole three times as wide as the root ball and mulch three times as wide as the hole.” or just “No Bare Soil… (anywhere)” -Villager
7) Water slowly and thoroughly. Newly planted trees and shrubs should be watered 2-3 x / week during the first summer. Approximately the “gallon” size of the pot in water each week, divided into three separate waterings (one 15 “gallon” tree needs ≥ 3, 5 gallon waterings per week) and about once a week in fall. Always send your garden into winter with moist soil. Even dormant trees need water. Water-holding gel will reduce irrigation demands. Plants will require less supplemental water every year but few will ever be entirely self-sufficient. Even native forests benefit tremendously from irrigation once a month in summer, especially during periods of drought. We like to say: “provide occasional simulated afternoon thunder showers”.
8) Tree Tying – After the leaves have fallen from your more brittle or vulnerable trees and shrubs, tie them up for the winter. Starting at the bottom, wrap the branches and trunk together as tightly as possible, using heavy-duty (1” x 8mil Villager-brown) tree tape to the top. We actually asked the manufacturer to begin making brown tree tape instead of the odd colored green. Then wrap down, binding the wrapped tree to the sturdy stake. In extreme snow-load areas, an extra bamboo stake may be tied up the center of the tree (in conifers especially) to splint the leaders. Only wrap for the first few winters or until they grow above the settling snow level. Late winter and summer pruning helps build sturdier branches.
Untying – Late winter snows are often wet and damaging to young trees that have been untied too early. Late April is a common time for local gardeners to begin removing the tree tape. Be careful of any tender new buds.
Pruning – Pruning is best done in late winter and through summer, for the first few years, in order to promote an excurrent habit, reduce excessive growth, produce strong branch shoulders, and create stout branches. Sturdier trees tolerate heavy snow-loads without needing tying. Do not prune in fall. (see urbantree.org: Tree Training Cue Card)
9) Protect the trunks of young trees by shading them with trunk protectors. Our low-angle Sierra winter sun will damage thin-barked deciduous trees with extreme temperature fluctuations and desiccation. Trunks may thaw during sunny days but when our temperatures drop too precipitously in clear evenings, water in the cells turns to ice and cells rupture. Water can move out of cells into intercellular spaces and lower the freezing temperatures in cells but this happens very slowly. Most trunk protectors also protect trees from winter damage by rabbits, rodents and deer (eating and rubbing antlers). Solid trunk protectors are removed during the growing season and sturdy grid-types are usually left on. Root guards are frequently used to prevent damage from burrowing gophers and voles. The stainless-steel mesh socks fit over the root balls and last for years, breaking only when roots push through them.
10) Fertilize regularly (1-2x / year). Just like the compost in the soil, the nutrients you add when planting are broken-down and consumed. Then your plants are left trying to eek-out survival in our poor native soils. Our “top-soil” is what everyone else had 20 feet down, base material, sub-soil. Actually, our native soils are not ALL bad, they are just lacking some of the very most important elements of a healthy soil for plant growth.
We have seen hundreds of local soil tests over the decades and with the exception of one that had arsenic and one with boron excess, all the others said the same thing: We have a silty loam with plenty of micronutrients (see glacial rock dust = our soil), we have enough (not great but OK) P&K (phosphorous and potassium – the second two numbers on a fertilizer label), and we are lacking Calcium and Sulfur (very important to a few species). What we entirely lack are nitrogen (N – the FIRST number on a fertilizer label and THE main plant nutrient that allows for the making of chlorophyl), and organic matter (we have .002%-.007% while a healthy topsoil has 5-10%). Thus, when we add composts at planting and mulch over the bare ground, we solve the organics issue. When we use Biosol or G&B fertilizers twice a year we replenish the fertility (and add more organic matter). We do fertilize and mulch even many native plants though we often use fare less… even native plants grow better in the wild when they find themselves growing in a location with better soil.