How to compare the shop for trees
Counting sheep for relaxation is not as effective as making your way through the American Nursery & Landscape Association (ANLA) American Standard for Nursery Stock, a 129-page book that explains in detail how woody plants should be evaluated and ranked. As boring as this book may be, it is full of tables and diagrams detailing exactly how to classify each type of woody plant and then categorize it. Understanding these standards is essential for nurserymen who buy and sell trees on sight.
Back when we had a retail nursery, we got a lot of calls from people buying nursery trees over the phone, and after asking for the price, they asked us’ how much is it? This is an obvious question, but the answer can be very misleading, as most types of trees are not bought, sold or valued for their height. Nurserymen classify tree size by trunk gauge (trunk diameter six inches above the ground) or container size, and the standard that applies will depend on the type of tree. They also refer to trees by their botanical (Latin) names, as common names are not specific enough to indicate what type of pedigree a tree has.
The best way to compare trees is to see them physically. There are so many variables that affect the price that it is impossible for the average consumer to judge and compare trees over the phone. For example, let’s look at the popular ornamental pear tree “Cleveland Select”. This tree is often sold “container grown”, in which case its price would be calculated based on the size of the pot. However, a pear tree grown in a five-gallon container can range from a one-inch caliper to over two inches (twice the size). It could be a branchless “whip” still eight feet tall, or a beautifully branched “lollipop” shape just six feet tall. A “ball and burlap” (B&B) pear tree dug in the field might have a nice, thick trunk and a well-branched crown, but a root ball too small to survive transplanting.
Smaller size B&B trees are often “hand-dug” with small clods of roots. Machine-dug rootballs usually have a sturdy wire basket crimped around them to hold the roots together, but the size of the rootball can vary widely. The ANLA standards dictate the appropriate size of root ball for each tree foot, and this can vary by species.
There is also the question of the tree structure. Young trees should be carefully pruned to correct structural defects and promote healthy and harmonious growth habits. Some nurseries regularly shear tree tops to promote a bushier appearance, and some do not. Nurseries vary widely in the care with which they prune, the height of “limb up” shade trees, and their ability to control tree diseases.
ANLA’s complex standards allow nurseries to rank trees according to a uniform, industry-wide grading system, as long as nurseries are honest when judging their own product. Over the years, we’ve learned that it’s better for us to physically see and select each tree we buy, rather than depending on someone’s description. We have literally “creamed the cream” of the large nurseries by selecting the best trees from rows of hundreds or even thousands, choosing only the best examples. Doing this over the phone takes trust; nurseries that follow ANLA guidelines present a better risk.
Organizations like ANLA are very helpful in setting industry standards. Bids and written specifications depend on well-followed guidelines to establish a “level playing field” for competitive bidding. For the owner, that’s way too much detail, but it’s important to understand that just comparing the height or size of the container won’t tell you much about the quality of the tree. No two trees are alike. Getting expert advice in person from a trusted nurseryman is the best way to get your money’s worth.
Steve Boehme is a landscape designer / installer specializing in landscape makeovers. “Let’s Grow” is published weekly; Column archives can be found on the Garden Advice page at www.goodseedfarm.com. For more information, visit www.goodseedfarm.com or call GoodSeed Farm Landscapes at (937) 587-7021.