On 10 Mar 2005 09:13:38 -0800, (Earl) wrote:
Potted plants
Usually, it's the smaller plants that you can buy in pots, but you'll
sometimes find larger shrubs sold that way, and the planting procedure
is the same for all of them. First of all, dig a hole approximately
twice the width and depth of the container, add some organic matter
and refill the hole about halfway with some of the soil.

Tap the pot a few times to loosen the plant and it should slide right
out. Put it into the hole and gently spread the roots out, being
careful not to break them. It's a good tip to seat the plant so it is
about an inch higher than it was in the pot to allow for it to settle.
If it is sitting too deep, simply lift it out and add a bit more soil
underneath it. When it's at the right height, carefully start filling
soil in around the plant, adding water every so often to prevent air
pockets and to keep the roots nicely moistened. Add a little mulch...
stand back and congratulate yourself!

Around here, you can often find container-grown trees, as well, and
this is not how to plant them. All the studies I've seen show that
the best results come from diggin a hole three times as wide as the
root ball, and as deep as but no deeper. The backfill should be the
same soil that came out of the hole, with no amendments.

Trees are very sensitive to having the trunk flares buried, so special
care should be taken to determine where they are before planting.
Often, each time the tree gets repotted it gets planted a little
deeper, until the big containers have a tree with several inches of
excess soil at the surface. Adventitious roots in this soil then
become girdling roots as the tree grows, exacerbating the problem. It
may be necessary to remove several layers of fine root mats from the
top of a large container-grown tree before you can locate the original
soil level.

One place the above instructions apply to trees is when it says to
plant a little high--even after finding the flares and locating them
at grade, sometimes we end up with deep trees after soil settles (one
big reason not to dig a hole twice as deep as necessary). Once the
recommended three-inch layer of mulch is added, the flares are buried
quite deeply once again.

One final amendment to the "rules" above: often, container-grown
trees stay in the pot too long before getting bumped up to a larger
one, and in the interim roots circle around the outside of the pot. A
few years later, the roots are nice, thick rings and the trunk has
grown to meet them, and the result is one or more girdling roots that,
once again, compromise the root flares. It's hard to do anything
about this if it happened three pots back, but you can avoid some
girdlers by slicing vertically through the outside of the root ball in
two or three places (theoretically the same thing is achieved by
"gently spread[ing] the roots out," but it can be difficult to
untangle them in a severely rootbound tree). This is one good reason
to plant smaller trees rather than large ones. Another is that the
small trees will establish themselves in the native soil much quicker
and eventually overtake the larger ones. The most obvious is that
small trees are much, much cheaper and easier to handle.

Otherwise, I agree with the above completely.

Keith Babberney
ISA Certified Arborist