Last month Susi Mastroianni wrote “How to Plant a Tree“. This article will complement hers by discussing considerations you need to make when selecting a tree you want to plant.
It is important to buy the right tree because trees are a big investment. There is the initial cost of buying the tree, the cost to haul and plant it, and the long term costs to care for it.
You cannot plant a tree and walk away, especially when planting in an urban environment where survival challenges are more intense than if the tree were growing in its natural habitat. The tree needs to be watered, fertilized, pruned occasionally, and have its rubbish raked and picked up.
But the benefits more than make up for the costs. When grown long term, trees provide: great cooling shade, colorful flowers, fruit, architectural enhancement of a structure, increase of property value by as much as 10-12%, habitat for wildlife, a sound and visual barrier when properly placed, a decrease in rain water runoff, the oxygen we breathe, a decrease of carbon dioxide, a reduction of global warming.
Prior to buying the tree, you need to know:
The Site – Unfortunately trees are not adaptable to all the site variations found in our typical landscape. The Maui County Planting Plan shows five environments that plants are exposed to: Wet areas – windward part of the island; cool, dry areas in higher elevations above 1,000 feet; low, drier areas that are warm to hot; lower elevations that are wetter due to proximity to mountains; and salt spray zone in coastal areas on the windward sides of the islands.
In addition to these environmental conditions one should be aware of site conditions such as soil pH, salinity, and depth, and whether there are underground water and utility lines. An adequate above and below ground space is needed for a full tree canopy to be supported by a large root mass.
The Species – References such as Plants for Tropical Landscapes, A Gardener’s Guide by Rauch and Weissich, A Tropical Garden Flora by Staples and Herbst, Guide to Landscape Palms by Meerow, and of course the Maui County Planting Plan by the Maui County Arborist Committee are some of the many references available for your use.
In addition, your personal experience with the species, or just seeing how it does in the neighborhood you want to plant it, will give you some idea whether that tree is suited for the chosen site.
The Maui County Planting Plan (MCPP) contains 21+ characteristics (canopy spread, wind and salt tolerance, planting zone, etc.) for many of the commonly planted trees, ground covers, and turfgrasses. It does not include fruit tree information because they are not planted on streets and in parks. You can get a copy by contacting the County Parks & Recreation Department and paying a minimal price. This document is being revised and will include new plants but no invasive species. It will include new chapters on parking lot trees and invasive species. Completion date is hopefully two years away. County Administration support and Council action are needed on some important issues before the document is released.
The Nursery – Once you have the right species for the site you need to find where it can be bought. Because of the busy construction period Maui is experiencing many nurseries have placed on hold trees destined for landscape projects in progress. Available trees frequently are off grade and will need a lot of training. Healthy fruit trees are available at local nurseries because they are continuously provided by nurseries such as Plant It Hawaii and Frankie’s.
“Eye Balling” the Tree:
Roots: Do not buy a tree with woody roots circling a pot’s soil surface. Tender soft roots circling can be opened-up at the time of planting. A tree with woody roots sticking out of the drainage holes is a sign of being “pot bound”. Do not buy it. I am known to shake out a tree from its pot and have a look at its roots if I suspect problems. Years ago 3 & 4 foot citrus trees came in one gallon pots. Woody circling and kinked roots were common. The public became educated and rebelled. Today they are grown in large grow bags or pots.
You want a tree in balance with its pot size. You want a tree to have enough roots to hold onto the soil at planting. I have seen a pot carefully cut to facilitate removing the tree and the entire medium fall away when the tree was lifted. The roots hung like you were grasping the handle of a water mop. Panic!
Buy a tree whose size is proportionate with the pot to avoid “pot bound” problems. Roots should be white and not brown or black.
Trunk: A single upright trunk is ideal. If only trees with multiple trunks are available, tip the weaker one(s) to subdue them and let it produce photosynthates until the tree is growing well. Then remove the subdued leader(s) leaving just one main leader.
If many of the young tree’s branches are growing upright at angles less than 45 degrees this will make for bark to be included (squeezed) between the branch and trunk. If branches with included bark are retained, they are poorly attached and may become problematic as they mature and become heavy.
Buy a tree with a single trunk with branches distributed around the trunk and emerge from the trunk at angles between 45 and 90 degrees. The trunk should be tapered, larger diameter at the bottom and smaller at the top.
Leaves: They should be evenly distributed on the upper two thirds of the tree and its branches. They should be green, healthy, and free of insects; check both sides of the leaves for pests.
Buy a tree that is vigorous, has many healthy green leaves, and has no insect pests.
In summation a healthy small tree growing in a container of a proportionate size will adapt to a site better and faster than a larger tree with root, leaf, and trunk problems.