Do you really know how to plant a tree so that it survives and thrives? Probably not! Many people make mistakes when planting a tree. In recent years, pros who study tree growth have learned new information and have changed the standard planting advice.
Here, based on the latest scientific knowledge, are the common mistakes to avoid…
Mistake: Digging the planting hole too deep. If it’s too deep, the tree’s roots could rot. Instead of measuring from where the trunk visibly meets the root-ball to the bottom of the root-ball, measure from the “first root flare” (the spot where the first lateral roots start) to the bottom of the root-ball. That’s how deep your planting hole should be.
Mistake: Not allowing for root expansion. Make your hole at least a foot wider than the root-ball on all sides. Tree roots grow outward, and you want them to—they will stabilize and anchor your tree over time.
Mistake: Holding your tree by the trunk. Yanking a trunk can break roots near the center of the root-ball or scuff tender bark (which invites disease and insects). Move your tree only by hefting the root-ball.
To get a tree from your vehicle to the planting site, use a wheelbarrow or put it on a tarp and drag the tarp over. Gently maneuver the tree into the hole before snipping off any twine or carefully tugging away burlap (leaving it on until then protects the root-ball from damage or drying out).
Mistake: Adding organic matter. Current thinking is to not add organic matter (such as compost, peat moss or dehydrated manure) to the hole when planting a tree. Research has shown that this causes the roots to stay right in the area and can stunt growth. Refill the hole with the soil you dug to make it.
Mistake: Hasty hole-filling. Shoveling the soil back in all at once, without taking time to water, is bad for the young tree. In the following days, vulnerable roots may dry out in air pockets and the tree may lean or fall over because it’s not securely settled.
Instead, just after you position the tree, fill the hole about halfway, firmly tamping the soil with your hands or the back of the shovel as you do so. Then fill the hole with water, and let it soak in. Continue adding soil to fill the hole completely. Water again, pressing in more soil.
Mistake: Allowing water to run off. Water delivered directly to the root system is critical to getting a young tree off to a good start. After the tree is planted and watered for the first time, as described above, use your hands to construct a basin—that is, a several-inch-high dirt berm in a circle around the planting hole’s outer edge. Fill with water, and watch it soak in right where it is needed. Do this daily, unless it rains, for the first several weeks of its new life.
Mistake: Skipping mulch. Mulch holds in soil moisture, moderates soil-temperature fluctuations and keeps out competing weeds. So on planting day, lay down bark mulch that is three-to- five-inches high over the previously described basin—but an inch or two away from the trunk to avoid bark decay.
Mistake: Staking unnecessarily. Unless your tree is in a very windy spot or especially top-heavy, anchoring it with stakes and lines—which many people automatically do when planting trees—actually can do more harm than good. The ties holding the lines to the trunk can abrade bark, inviting disease…and the tree may not grow as strong because it will depend instead on the support of the lines.