As some of you know, my background is somewhat different from most faculty members in Horticulture in that my roots (no pun intended) are deepest in forestry. I’m sometimes asked to compare and contrast various aspects of horticulture and forestry. There are certainly differences – some of which I’ll get into in later posts – but there are also a lot of similarities. One of the truisms that seems to pervade both fields goes something like this: “When all else fails, blame the nursery”. Whenever a tree dies, whether it’s a 2-0 bare-root seedling or a tree that was spaded in with 60” tree space, the first reactions is “Must’ve been bad nursery stock”. Um, could it have been that the tree planting crew left the bundle of seedlings in the 90 degree sun all afternoon or that 5” caliper red oak really doesn’t belong in a bathtub? I bring this up because often we see suspicion, if not downright hostility, aimed at landscape nurseries. I thought of this as I was touring J. Frank Schmidt and Sons nursery this week near Boring, Oregon (yes, there really is town called Boring). J. Frank Schmidt and Sons is one of the largest wholesale producers of shade trees in the country. If you walk into virtually any garden in the northern half of the US, chances are you will see trees that began their life in the Schmidt’s fields under the shadow of Mt. Hood. J. Frank Schmidt nursery is among the most progressive nurseries in the industry, investing in new plant development, in-house research, and supporting university research through the J. Frank Schmidt Family Foundation and donating thousands of trees for research trials. During the tour, our host. Jim Ord, was excited to show us an air-slit container that Schmidt had developed for to reduce circling roots in container-grown trees. As I mentioned at the outset, we are often quick to blame nurseries for causing problems, here’s an example of a nursery working to solve problems. And this is just one example, Schmidt and other nurseries are working to develop and promote new elms and other species to provide a wider array of trees to replace ash trees in the wake of the Emerald Ash Borer. In some ways Schmidt is unique due its size and progressive stance but other ways it is very similar to a large majority of wholesale nurseries which with I interact. While there are certainly issues that trace their roots to problems in nursery production, most nurseries take great pride in their products and work constantly to refine and improve their growing techniques.
I too span the fields of horticulture and forestry (i.e. arboriculture); I work only with woody plants and spent my post doc in a forest products lab. A few years ago, I did a root washing demonstration at an ISA conference. We bare-rooted a tree bagged in a similar manner (different company). While the outer roots were great, the interior roots were fatally flawed. These containers only work if the seedlings planted in them are not allowed to develop poor roots prior to bagging. (The problem stems from leaving seedlings in liners or containers too long so that their primary root system begins to circle or kink.) This particular company's tree quality was so uniformly poor in terms of these interior roots that at least one parks arborist refuses to buy them any more. Many ISA certified arborists recommend that people only purchase bare root stock, rather than dealing with the problems in many containerized and B&B trees.
Hooray for bare-root trees! Here in MA we see so many B&B trees with buried trunk flares (swallowed up by root ball soil that runs 4-8" up the trunk) that it's become rare to find a tree that's burlapped at the right grade. My understanding is that nursery cultivation practices, and then the squeezing of the wire baskets during transport, pile the soil up. I'm a landscape architect & ISA-certified arborist, and find myself at every site educating the contractor and laborers on how to excavate the trunk flare, something they're not always thrilled to do when they're trying to finish a job fast. It can make for some tension in the field….but the longevity of the tree or shrub depends, in part, on planting at the right depth.