Can you plant trees during summer in Alaska?

I know “fall is for planting,” or at least supposed to be, but can you plant trees in the summer? This is a question I get all season long — and, I might add, every summer as well. Since you live in Alaska, the short answer is yes. A longer answer is yes, definitely yes.

It seems everyone has heard the call to plant trees in the fall. This has three origins. The first is that some association figured this would be a great way to sell trees. They were correct.

Second, it is way too hot Outside in many places to plant in the summer as newly planted trees can easily become stressed. In fact, over 80 degrees and things pretty much stop growing, so you an imagine what would be happening when it is 100 degrees.

The third reason people plant in the fall is because deciduous trees drop leaves then. Without the need to support leaves, a tree can concentrate on getting its root system established take advantage of any planting time.

Any high temperatures here, our new trees can handle. And, as good gardeners, Alaskans know to just pay attention to anything newly planted, so there won’t be problems. Go ahead and plant.

If you do plant a tree this summer, rules have changed over the past 10 years. It used to be simply dig a hole, add some fresh soil and stake the tree after planting. Not so today.

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Let’s start with the hole. When planted, it is critical that the soil line be just where the trunk of the tree begins to flare. Just an inch deeper or an inch shallower can cause real problems including the death of the tree. The flare should be easy to spot: The bark is probably a different color, for one thing. And you will see where the trunk thickens. If in doubt, ask the people where you buy trees to mark it for you.

You should not dig to China and then back-fill until you get the right depth. The soft soil at the bottom of the hole will settle after it rains and then your root ball will be too deep.

Instead figure out the right depth and make that your hole that deep. You can adjust later.

The hole should be three or four times wider than the longest roots. Remove any burlap, netting or straps and spread roots out as much as possible without damaging them. It is much easier with bare-root trees. You can build a cone in the hole and spread the roots outward over it.

Fill the hole with water and let it drain. Then plant. This way, there is plenty of moisture in the surrounding soil and you won’t have to water as much while roots establish.

It is important to backfill with the native soil. In the past the advice was to fill with good compost or soil full of organics. However, roots will tend to stay in the hole because of this better soil and grow into a ball instead of reaching out beyond the drip-line.

If your soil really needs organic matter, say when planting in a new subdivision’s soil, mix no more than 10% good soil in with the native. If using native soil causes some concern, look around. Those trees you see probably did not get planted in compost, but rather native soil. Oh, and no bone meal or fertilizers at planting time.

Once the tree is in, water again to settle the soil around its roots. Then apply a layer of leaf mulch out at least to the drip-line. This will keep weeds down, help regulate water and as it decays, start feeding the tree’s soil food web.

Finally, no staking. It prevents the tree from learning to deal with the stress of winds. The stress resistance developed in an unstaked tree helps that tree be healthier. Moreover, the tree can, and probably will, snap at the point where the trunk is tied. Let’ it sway is the rule. If you must, employ one stake, loose guy wire and use that only for a week or two.

So, yes, you can plant trees in the summer. Go forth.

Jeff’s Alaska Garden Calendar:

AMGA Late Season Plant Sale: Saturday, Aug. 12, 10 a.m.-3 p.m. in the Alaska Botanical Garden parking lot. The sale will feature plants, gently used good pots and tools for sale, plus three classes that run from 10:30 a.m.-12:30 p.m.

Alaska Botanical Garden: Visit! Sign up for the August walking tour to see what is in bloom. There are so many more activities you will need to register for: Join support and take advantage of great discounts like at The Garden’s Nursery.

Harvest: Eat what you sow. Or share it with someone who needs it.

Podcast: Every Friday get a bit more than just this column as a new “Teaming with Microbes” podcast pops out wherever you get your podcasts.

Jeff Lowenfels

Jeff Lowenfels has written a weekly gardening column for the ADN for more than 45 years. His columns won the 2022 gold medal at the Garden Communicators International conference. He is the author of a series of books on organic gardening available at Amazon and elsewhere. He co-hosts the "Teaming With Microbes" podcast.