Home & Garden

Branching out: Take care in buying, planting new tree

BOISE -- Trees are the middle child of home landscaping.

They aren't doted on like grass or bragged about to friends and family like the flower garden, but they crave attention, too.

"Trees are just like any other plant -- they need water, they have needs for nutrients from the soil, they occasionally will need treatment against certain types of pests," said Brian Jorgenson, Boise city forester.

Maintaining trees can be simple, but you have to know what to do -- and more importantly, what not to do -- to keep them healthy and happy.

Here's how.

Choosing a tree

Tree selection involves more than aesthetics. Climate, soil and surroundings all play a part.

Do research. Consider the tree's purpose. And take a good look at your yard.

"Look up, look down, look all around," Jorgenson said. "If you've got an overhead electric wire going across the front or side of your property, it's not a good idea to plant a 70-foot-tall oak tree."


"Look up, look down, look all around" also applies to planting.

To thrive, a tree needs to be in the right place to take in nutrients, avoid damage and grow to full size.

The first thing to look at is your soil. Its pH and density can affect how well the tree draws nutrients from the ground.

Proper spacing is key. Make sure you're not planting the tree too close to the house, sidewalk, patio or other obstructions.

Dig a wide planting hole, but not a deep one. If planted too deeply, the tree's trunk tissue can come in contact with the soil, causing it to rot.

Jorgenson recommends a layer of mulch around the tree. It will help keep the soil cool and moist while protecting the tree from weeds and damage.


As with grass, the key to watering a tree is to water longer, but less often. "The idea is to get the water to penetrate deeper, which is great for the tree because getting the water deep into the soil helps the roots," Jorgenson said. "The soil stays cooler and moister."


Fertilizer is not food -- it's more like vitamins, Jorgenson said. It can be good for a tree, but it can be bad for it too.

If you fertilize your lawn, that's generally enough for your trees too, Jorgenson said.


"Whether you're doing a young tree, old tree or middle-aged tree, there is a good way to prune and a lot of bad ways to prune," Jorgenson said.

Topping is the worst of the bad ways, because it cuts off much of the tree's food-making capability.

When topped, a tree hurriedly grows new branches and leaf area to sustain itself, but this new, weaker growth is attached to the topped branches, which have begun to decay.

There also are good and bad times to prune. Spring generally is not a good time, Jorgenson said, because a tree is using resources to grow. Pruning then makes it vulnerable to pests and disease.

The best times to prune are generally the summer and winter, Jorgenson said.

For major jobs, Jorgenson recommends hiring a tree service that is licensed.

Pest and disease control

Keeping a tree free of harmful insects and diseases is a matter of preventive maintenance.

Like humans, if a tree is healthy, it will be well-suited to stave off illness.

When problems do arise, use the least toxic means to take care of them, Jorgenson said.

Don't rush to spray chemicals all over a tree just because it is covered in bugs. That may not be a bad thing.

"There are a few insects that are annoyances to us but don't really do all that much damage to trees," Jorgenson said. "The majority of insects are mostly beneficial to plants and trees."