How To Care For A Young Tree

by Susan

The decision has been made, the hole dug and the tree planted, following all the instructions of course! Now what? Research has shown that newly planted trees take two years to establish. During that time young trees or older trees that have been transplanted are sensitive to environmental stresses, nutrient deficiencies and pest infestations and should be monitored closely. A young tree needs to be nurtured and given a good start in life in order for it to grow into a fine mature specimen. Don’t be too surprised if you don’t see much growth at first. It’s often the third or fourth year after planting before good growth starts, especially if conditions are less than ideal.

A mature tree can have a root system that extends at least to the edge of the canopy, if not farther. The roots can spread as far as 2 to 4 times the height of the tree. A newly planted or transplanted tree will have a root system only a tiny fraction of that, and the first year or two will put most of its energy into establishing its roots.

Watering is critical. Roots won’t grow into dry soil, but overwatering can cause root rot. Water needs to be applied evenly around the root-zone. If one side is dry the tree will respond as if the whole area was dry. Small root balls tend to dry out quickly and need to be deeply watered once or twice a week throughout the growing season. To determine if watering is required, test the soil around the tree by digging gently with a hand fork or a digging fork. If the soil, four to eight inches down, is dry or only a little damp, then the tree needs water. Don’t assume that a little rain in the summer will be enough. Neither should you assume that a sprinkler system is delivering the right amount of water to the right place. Always check that the water is directed at the root ball in sufficient quantity to keep it evenly moist. Even with plenty of water, a new tree may be drought-stressed because it simply doesn’t have a big enough root system to draw up the moisture needed to sustain itself.

Mulching is one of the most beneficial things that you can do to keep your trees healthy. Most of the fine feeder roots are in the top few inches of soil and a 2 to 4-inch layer of leaves or composted chips or bark enables them to get oxygen and moisture without having to compete with the lawn. The mulched area around a young tree should be 3 to 4 feet wide, which should also be enough to protect it from damage from lawnmowers and string trimmers. Ideally, the whole area under the canopy should be free of turf and mulched, but in most gardens that is just not practical. A word of warning… Avoid piling mulch up against the trunk of the tree as that will cause rot and other problems.

Damage from wild life can permanently injure young trees. Around here the biggest problem is with deer. In the fall the bucks like to use any tree with a small diameter trunk as a scratching post, stripping off the bark or even snapping the trunk right off. Protect the trunks with wire fencing or tree wrap.

There are many opinions on the subject of fertilizing young trees. You should never fertilize a tree that is under stress due to dehydration, insect problems or disease. One school of thought says that newly planted trees are by definition stressed out in their first growing season and should be well watered but not fertilized at all. Another holds that a judicious application of slow release fertilizer in the spring is beneficial. To be most effective, fertilizer must come into contact with a tree’s feeder roots, which are at the dripline and beyond.

pH matters. Soil testing is something that most gardeners know should be done, but never quite get around to. There are two main goals in soil testing, one is to determine the levels of nutrients in the soil and the other is to determine the pH of the soil. pH is the measure of the acidity or alkalinity of the soil and the reason that it is important is that it has a direct relationship to a plant’s ability to take up nutrients. Plants are programmed to grow best at a predetermined pH level and while some plants are adaptable to a pH range, others have very specific needs. Around here the soils tend to be on the acid side and coincidentally (or not) many of our garden favourites like maples, dogwoods, oaks and conifers happen to love acid soils. The point is that if you’ve done everything you can and your tree still isn’t happy, the pH may be incorrect and soil amendments may be required.

Pruning and Training: Young trees need formative pruning to ensure they grow into safe and healthy mature trees, with strong trunks and sturdy, well-placed branches. Initial pruning should have been done by the grower, but it’s an ongoing process. It’s too big a subject to do justice to here, but there is lots of good information on pruning and tree care to be found on the International Society of Arboriculture website: