Mature trees have been known to have roots extending from the trunk a distance equal to three times its height, so long as there are no obstructions. For obvious reasons, it is not feasible to provide the entire root system of these trees. So root balls are sized appropriately so the tree will live, but allow for easy transport. So why does this matter? A larger tree is missing much more of its relative root mass as compared to a smaller tree.
When you plant new nursery stock, the tree's first goal is to re-establish its root mass. This is called transplant shock, and during this time, the above-ground size of the tree may change very little. So that larger tree must spend more time trying to recuperate its root system. As a general rule of thumb, you can expect one (1) year of transplant shock per each caliper size of the tree.
In a practical example, you can plant a 1” caliper tree (6' tall) next to a 3” caliper tree (12' tall) at the same time. The tree may grow up to 2' per year. The smaller tree regains most of its root mass in the first year, and it can grow steady for the next two resulting in a height of 10' before larger tree even starts growing. By the time the larger tree starts growing, the trees will appear to be relatively the same size. Now you can buy these smaller trees at home depot for less than $100, in many cases. The same species at the larger size from your local nursery may cost as much as three times that price. But that's just the material costs.
Here's another important fact: Regular watering is essential for survival during this transplant shock period. You'll only need to water the smaller plants during the first year, where the larger plants may require additional watering for years to come. Especially knowing that in 10 years all these plants will look the same, don't you think it's worth having a little patience?
One of the biggest ways to save money is to select the best plants. Do your research. You'll want to select native plant species that are well suited for your area. Those Asian varieties may look nice, but they will not be nearly as well suited for your yard as a native plant. Besides, native plants are often cheaper. If you're unsure about what is native or not, check with your local environmental organizations or the state's Department of Natural Resources. Even among your natives, some plants won't handle certain conditions such as shade, excessive sun, wet soils, dry soils or even salty conditions. You need to evaluate the area where you want to plant.
Observe for several days to determine these conditions, and keep these in mind when selecting your plants. Most nurseries will have tags that tell you the ideal conditions for a plant. If not, ask for help, or check online resources. And don't be afraid to mix it up. You want to avoid monoculture, a large number of plants with the same species. A monoculture results in disease susceptibility.
Blights and widespread plant disease is not entirely uncommon, and they can evolve over time. But if you have one-hundred Pine Trees planted along the back of your property and disease comes around that specifically attacks Pine trees, guess what? You've lost your entire buffer. Diversity in your landscape not only provides some protection from this, but it also provides a much more natural appearance.
Other Considerations
Landscaping is more than just lawn, trees and shrubs. There is a whole industry that caters to landscape maintenance and installation. You'd be surprised how many products are available that are absolutely not necessary.
One example: Tree wrap. It has been found many years ago that the wrapping of your tree trunks does very little to help a given tree survive. It can actually be a hindrance. It may over-insulate the tree trunk in the winter resulting in bark splitting, a condition known as sun scald. It can also be host to insects, not only providing a nice home for them, but preventing you from detecting insect problems early. I offer one caveat. There are a number of products designed to protect tree trunks from weed eaters and lawn mowers. These are often hard-plastic tubing designed to shield the trunk, but they can be installed without actually touching the bark. These are acceptable so long as they are removed before the tree grows too large. Ideally, trees should be installed with a mulch ring, and this product won't be necessary. But such practices aren't always possible.
Plant insect sprays are not always necessary. There is a relatively new philosophy known as Integrated Pest Management (IPM) that strives to avoid the unnecessary use of chemicals. The idea is that you identify the problem and potential damage before you spray anything. For example, Hemlocks are known to acquire a pest called Wooly Adelgid, an insect that looks like cotton around the stems and leaves.
