Friday, June 30, 2006

How to plant a tree.

I've planted a handful of trees this summer and out of several nurseries I've been to, two of the best had instructions on how to plant a tree so the tree will actually make it in most conditions. Up until that point I never thought much about the process. The tree I planted year before last died, so maybe I should have thought more about it. Wasilla doesn't have good soil conditions at all. It's all gravel and rocks or mostly clay except a very thin layer of topsoil around here. Up until this summer I guess I've always taken Homer's great soil conditions for granted.

Anyway in different conversations I found a lot of people (who are into gardening) didn't know most of this stuff either. Some of them just happened to have great (soil) conditions, and the others new a trick or two to get them by. So for those who requested this and others that could benefit, here it is...


The "how to plant" that's below is a general for all trees but, When buying a tree it's good to ask your nursery or search online for your tree's specific needs. As an example...

Birch trees thrive where conditions are sunny and the soil is well drained, somewhat sandy but high in organic matter. Their roots stay near the surface but spread far, so I was able to plant them near my leach field as they won't interfere with the system.

Lilac trees have roots that go deeper, so I wasn't able to plant it near my leach field.

Elderberry trees will grow just about anywhere and will help improve soil over the years so I was able to plant them in the spots of my yard where the clay is concentrated.


When planting a tree...
Until you can plant your tree, keep its roots damp, either heeled into soil or wet sawdust and in the dark (or at least shaded). Try to get them planted as soon as possible. In Alaska most tree and shrub roots grow in the upper 12-18 inches of soil and spread far beyond the drip line of the tree (as illustrated below). A bareroot tree, as well as a "containerized" or recently planted tree has lost about 90-95% of its existing root system, therefore the better you treat the roots the more successful your tree will be.

(Click on photo to enlarge)

  • Is the tree far enough away from houses, roads, sidewalks for proper root development and from overhead wires for upright growth?
  • Plant smaller trees (up to 25') at least 10' from a structure and larger (up to 50') at least 20' away.
  • Will the tree obstruct a south facing window as it grows?
  • Is the site shady, sunny, wet, windy etc?
  • Will the site have a lot of runoff in the spring?
  • Will salt or other chemicals run into the root zone?
  • Is the site needed for snow storage, or is it in a snow shedding area?

SOIL CONDITIONS (many sites have poor soil conditions in Alaska.)
  • Is the soil composed of heavy clay, with poor aeration and drainage? Cherry trees especially don't like "wet feet".
  • Is it too sandy (which won't hold water) or a good loamy mix with good aeration, drainage and water retention?
  • Is the soil shallow over hardpan or permafrost and thus poorly drained?
  • Is it very hard and compacted with rubble and debris or composed mostly of gravel and rock?

  • It is NOT usually recommended that a fertilizer be used (when planting), especially one containing nitrogen, which promotes leaf growth.
  • Phosphorous, to promote root growth IS RECOMMENDED (in the form of rock phosphate or bonemeal) as is a slow release fertilizer such as Osmocote.
  • Many nurseries use a rooting hormone along with vitamin B, such as Upstart or Liquinox a few times after planting.
  • The best approach is debated among growers
  • Most trees die of lack of water, give it a deep watering once a week.
  • Keep grass from growing in the hole you dug for at least a year or so, grass or "sod" robs most of the trees water.
  • Wrap aluminum foil or a metal grid mesh (the tip of your pinkie should not be able to fit through the grid holes) around the bottom of the trunk (about 1 & 1/2-2 ft high) before the snow falls to keep voles or shrews away. Although some trees are bypassed, these critters can kill a tree.

Most tree roots grow in the top 12-18 inches of soil, therefore the goal is to help the roots grow into the surrounding soil rather than remaining coiled in a planting hole. Growing into a coil will eventually strangle the tree and cause it to die or fail due to limited root spread.

A large area approximately 3-5 times the original root area should be dug and if needed amended with sand or loam. Do not however add more than 1 part amendment to 2 parts native soil or the roots may not spread into the native soil outside the prepared site. If you make your planting hole too "sweet" by replacing all the native dirt with yummy compost the roots will not want to grow outside it's hole and will become coiled as warned of above. (I think this is why my tree I planted 2 summers ago died, I replaced all the not so great soil with store bought good stuff and the hole I dug was just enough to fit the roots in, and no bigger. Ha, no wonder it died!)

(Click to enlarge photo)

Remove vegetation and rototill or dig the soil as shown above. Slope the sides, loosen and roughen the slope as root tips will penentrate this easier. A pitch fork works great for stabbing at the sides of the tree hole to roughen & loosen it up and allow space for roots to grow once they're ready to go beyond your prepared area. In the center, dig the hole only as deep as the natural shape of the root area. If dug too deep the soil will settle leaving the tree in a depression which will eventually fill in at which point the tree will be planted too deep and it will die. It's better to plant a tree to shallow than too deep. Some fruit trees will tolerate being planted deeper than the trunk flare.

Prune away any diseased, damaged, or circling roots. If the roots are rootbound return the plant. If you can't return the plant use a sharp cutting devise of choice to cut 1/2 an inch in, all the way down 3 sides of the ball and loosen the roots and dirt as much as possible.

IF your tree is litterally bare roots, with no dirt what-so-ever leave a small firm mound of soil in the center of the hole and spread the roots out over this. If your tree came in a pot compacted in dirt, skip this mound suggestion.

Set the tree in the hole so that the trunk flare is slightly above the ground level. Turn the tree so the branches face the way you want. Backfill the tree hole, removing rocks and breaking up clumps. This is a great time to layer in your bonemeal, 5 cups scattered through out the hole and around the roots will help the roots grow. I've heard you can't over do using bonemeal or other phosphates. Soak the area thoroughly, this is a great time to use the vitamin B as it's directions show. I have been warned about using the vitamin B too many times though. You can build a berm of earth around the outer perimeter to help hold water but this should be knocked down before winter so a pool of water or ice does not deprive the roots of oxygen. Do not plant annuals or cultivate the soil in the area prepared.

Remember this: the single most important thing you can do is WATER: DEEP, SLOW, and OFTEN for 2 years. Avoid soil compaction in the root zone (drip line plus 10 feet).

Hope this is helpful, and good luck!


akscotts said...

kianna - i have learned one thing about you - when you do something you really go all out!! that is wonderful you found out all that info about tree planting. i'm sure your trees are going to thrive:)

Klondike Kate said...

Dang but that's a lot to know about planting a little tree!

Kiana said...

Our soil is really bad here. And with all the precautions I took I'm still *hoping* the trees don't die.

Toni Jackson said...

I'm sure, with all of that research, your trees are sure to survive. I planted some last year, some dogwoods, rosabella, and I didn't have a clue what i was doing, luckily they did survive, despite my incompetence.

Kiana said...

Ha, actually with all that one of my tree's got eaten by a moose **grrrr**. The rest look great though, so far!