Maui Association of Landscape Professionals

How to Plant a Tree

From the Spring 2007 MALP Newsletter
by Susi Mastroianni
Certified Arborist
Like children, trees (and other plants) benefit from having the very best start we can give them. There are many points to consider when planting a tree if you wish to enjoy it for many years to come.
Whether a fruit tree, shade tree, small ornamental or wind break, trees have many things in common. They need to be selected for the site in which they are to live, they need to be planted correctly and nurtured to grow to their fullest potential. All of us have enjoyed the shade of a tree or benefited from the fruits of their labor – here’s what they need when you plant them.
The tree – plant selection is of great importance. If you don’t know what tree to plant, do your homework. Read books, contact the Ag extension or call a certified arborist for a recommendation. No matter how well you follow the directions below, if the tree is not suited to the site it will not thrive!!
Plant selection – once you have identified which type of tree you will plant, selection of a healthy specimen is paramount. I will be covering that in the next edition of our newsletter.
The hole – Remember, what you see above the ground is only half the picture. The root system is the nutrient foraging department and if this is compromised you will not have a healthy tree. When digging the hole never be shy to dig it as wide as you can, 2 or 3 times the diameter of the pot size is always a good idea. Ensure that the sides of the hole are rough and broken not glazed and smooth, especially in clay soils. NEVER dig a hole that would result in the tree being planted lower than its current planted level. One of the #1 errors I see is trees planted to deep. Trees have a trunk flare at their base. (This can be less evident in younger trees.) This is the site where differentiation of function takes place. Above the flare should be above ground and below the flare should be under the ground. It is at this level that trees push out buttress roots to stabilize themselves as they grow taller and are subjected to greater wind stress. If you have, in error, dug a hole to deep, replace some soil back in the hole and TAPM it down. You do not want the tree to settle over time and result in the sinking of the root ball. This will result in the flare being below ground and will impede the creation of strong buttress roots. It is also a site of disease and pest weakness. It is better to plant a tree slightly shallow , +/_1-2 inches, above the natural grade then plant too deeply.
Amendments – Many people ask me what they should put in the hole when planting a tree. To be honest the size, depth and mechanics involved in placing your new tree in the ground is of far greater importance than selecting the latest trend in fertilizer tablets. The International Society of Arboriculture does not recommend amending the hole into which the tree is placed. The logic behind this is that no matter what you do to the 3 feet of soil around your new tree, it will, in time, need to spread its roots far from there and survive i n the native environment (once again Right tree Right place). You also run the risk of creating such a nice comfy home for the tree that the roots will not venture out in the big bad world of un-amended soil and you will have stunted root growth and possible girdling of the root system. (Girdling roots are roots that have turned in on themselves and are growing in a circular pattern as opposed to spreading out into the surrounding soil.) I tend to add a cup or three of worm castings and hand full of a combination of organic and slow release fertilizer to the back fill. My logic being that the tree is often spoilt with fertilizers in the nursery and I don’t want it to go cold turkey all at once- use only a small quantity and avoid salt based fertilizers as you run the risk of burning the delicate young root system. Tablets, if used, should be 1 to 2 inches away from the root ball.
Placing the tree in the planting hole - There are many ways you can buy trees, containerized, ball and burlap, bare root and field stock. For the sake of this article I am using containerized stock. When removing the tree from the pot be careful not to disturb the roots more than you have too. Try not to lift the tree up by pulling on its trunk. (You should never carry a tree like that either – hold the pot) Place the pot on its side on the ground and gently roll it while pushing on the pot to loosen the sides. Gently slide the tree out. At this point you can loosen the roots slightly by running your fingers over the sides of the root ball. It is best to have measured the depth of the hole you need prior to placing the tree in the hole. Sometimes the soil falls away from the root ball in plants that have not fully grown into their existing pot, you should re-measure and adjust the depth as needed. Place the tree in the hole so that the trunk flare is level or slightly above grade, or if you cannot identify the trunk flare, plant no deeper than the original depth of the pot.
At this stage turn the tree carefully so that you select it’s best viewing position. (If the tree is seen from one direction only put its best “face” forward.) Have your helper hold the tree in place and walk back to better view the tree from afar. Once you are satisfied that the tree is in the best position and depth, start filling the hole. Do not place all the soil in the hole at once but firm the soil in the hole as you go. I normally do that as my helper slowly adds more soil around the tree. By firming the soil you secure the tree in place and prevent large air pockets in the planting hole. I like to plant the tree slightly higher and build the soil up to allow for the water to run away from the trunk.
Once all the soil is firmly in the hole lightly tamp with your feet, careful not to press to hard and break the root system. I ALWAYS mulch any new plantings. Mulch helps with water loss, weed control and temperature stabilization of the young root system. Watering in of new plantings is essential to settle the soil in the hole and further secure the tree.
After care – when a tree is labeled drought resistant/tolerant this refers to the eventual status of the tree to withstand periods of water restrictions. Even the hardiest tree will need additional water until established. I try to ensure that a drip system is set up prior to planting. The best intentions to water by hand often end up with dead trees standing!
A note on trees in grass – If you must plant a tree in the lawn try to ensure that at LEAST a three foot or more diameter is cleared of grass. Young tress need time to establish their roots in their new environment and do not need the added competition of grass eating up the available nutrients. (Not to mention death by Weed eater). Once a tree is established, the shade from the canopy naturally prevents the grass growing close to the trunk. Give your new tree the space it needs. Also pay attention to the lawn watering heads. No tree likes its trunk sprayed on, especially up close. Select a site that will be out of the line of fire of sprinkler heads and, if possible, can have their own drip system for deep watering.
In our next newsletter we will deal with proper tree selection
– what to look for when choosing a good tree.
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©2008