October is the best month of the year to plant a tree here

Nurseries sell most of their stock in April because that’s when people feel like gardening. It isn’t when trees prefer to be planted.

#What a tree does after you plant it

A newly planted tree has a root ball that’s a fraction of the root system it had in the ground. Until it grows back out into the surrounding soil, it can’t take up enough water to support its own canopy. That period is transplant shock, and it’s the dangerous part.

Roots grow whenever soil is above about 40°F — which here means well into December, and again from February. Top growth stops long before roots do.

Plant in October and the tree spends six-odd weeks putting energy exclusively into roots, with no leaves to support, in soil that’s still warm and holds moisture. Come spring it leafs out with an established root system already in place.

Plant the same tree in May and it has to grow roots and support a full canopy simultaneously, going into the hottest, driest part of the year.

#The window closes at frozen ground, not at first frost

You can plant right up until the ground freezes hard. A light frost is irrelevant — the tree is dormant above ground and still working below.

In the Carson Valley that usually means through October and often into November.

#Plant it high, and stop building volcanoes

Two mistakes account for most of the trees we’re called out to look at.

Planted too deep. The root flare — where the trunk widens into the roots — must be visible at or slightly above the surrounding grade. Buried flares rot. If the tree came from the nursery with the flare already buried in the pot, dig down and find it.

Mulch piled against the trunk. That cone of bark heaped up the stem holds moisture against the bark, invites rot and gives voles somewhere to live while they chew the cambium. Mulch goes in a flat ring, two to three inches deep, pulled back a few inches from the trunk.

Dig the hole two to three times as wide as the root ball but no deeper than it. Wide gives the roots easy lateral run; deep gives you settling.

#Then water it through winter

This is the step people skip, and it’s the one that kills evergreens.

The ground freezing doesn’t mean the tree stopped losing moisture — needles transpire all winter. A tree that goes into a hard freeze dry can’t replace what it loses, and you get winter burn: brown, scorched foliage that shows up in February and gets blamed on the cold.

Give new trees a long, slow soak every few weeks through autumn until the ground is properly frozen. One hose on a trickle at the drip line for half an hour beats five minutes with a sprinkler.

#And skip the stake if you can

Most trees don’t need staking, and a staked tree develops a weaker trunk because it never has to resist the wind.

Stake only if the tree genuinely won’t stand up, or the site is brutally exposed — and then loosely, low down, and remove it after one season. Wire left on a trunk girdles it.

We plant trees and full landscapes across the Carson Valley, and October is a good month to get on the schedule. Tell us what you’re thinking.