Minnesota Bound Clip: Oaks & Air Pruning Pots

The second of three short clips aired on Minnesota Bound this past Sunday evening (and will repeat this coming Saturday) on KARE-11 here in the Twin Cities. (Click on the link to view - it's the "Rapala Almanac" segment right after the piece on smallmouth bass fishing. Which, by the way, I'd rather be doing right now!)

The theme of this piece was planting, especially in light of the massive removal and replanting effort we will soon be facing here in Minnesota as new Emerald Ash Borer hot spots keep popping up. My two pieces of advice:

1. Plant oaks - There are of course myriad reasons to plant oaks, but one of the main reason people don't plant them more often is the widespread perception that they grow too slowly. Overcoming the slow growth stereotype is surprisingly difficult, seeing as how it's patently false. Hopefully this segment will help, if only a little

2. Look for trees grown in air pruning pots - The nursery industry is finally starting to pay attention to root systems. The life span of urban trees planted in the 70s and 80s in the wake of Dutch elm disease has been abysmally, embarrassingly short. The primary reason: nursery and planting practices that mutilated root systems. Traditional plastic nursery pots tend to promote a circular, spiralling root growth pattern. After planting those spiralling roots continue to grow in girth around the main trunk, slowing growth and ultimately killing the tree. The tree literally strangles itself (think of giant pythons wrapped around the base of the tree and you've got the right idea).

Air pruning pots come in a variety of designs, but the concept is the same. Openings in the walls of the pot expose root tips to air, causing them to stop growing outward and forcing them to branch out. This creates a thick, fibrous root system and prevents spiralling or girdling roots.

Where can you buy trees grown in air pruning pots? Here's one place: Knecht's Nursery here in Northfield, MN. Owners Leif & Deb Knecht are great people and have what I have come to admire most in people: a willingess to rethink the way they do things, a desire to find better practices, and of course a deep and abiding love of trees!