Root Bound Tree? Try Root Washing Before Planting

Spring is overwhelming. There are a million things to do in the garden, not to mention all the family stuff. One daughter coming home from college. The other about to graduate high school and playing lacrosse all over the Chicago area. Everything’s a blur right now. Then I decide to plant a new garden complete with a Tina dwarf crabapple. Restraint is not my strong suit. It should have been a quick planting job. The tree was small, container grown in a 10-gallon pot. No big deal.

So I dug the hole, slipped the tree out of it’s home and realized this “quick” job was about to get a little more involved…and dirty. Not hard, just time consuming and time is limited right now. But I want to do this right. Trees are an investment, something you hope will last for many years, not just the immediate future. The condition of the root ball and the growing medium in the container told me this tree didn’t stand a chance if I didn’t intervene. I turned it into a bareroot tree. I can hear you muttering “You did what?!” Hang in there. It’ll all make sense in a moment.

Check those roots winding round and round in soil that’s completely unlike the soil in my garden. It’s heavy, loaded with clay. The container soil, well, it’s the thing that gardeners’ dreams are made of. A least mine, anyway. Loose, fast-draining, workable. My soil is dense, difficult like some people. Root washing is the best way to solve the problem. Oftentimes container-grown or balled and burlapped trees that have been hanging around for awhile develop root systems that run out of room. With nowhere to go, they run around the outside of the root ball, girdling it and ultimately choking out the plant. Plopping this tree as-is in my garden means the roots would continue to grow in this same circling pattern, never venturing into the surrounding heavy soil because

1. Roots have memory and will continue to circle once the pattern is established
2. My soil stinks compared to the stuff in the container. If I was that tree, I’d keep my roots where it’s easiest to grow, too! Like water, roots take the path of least resistance.

So I have two options: plant as is and enjoy the tree for a few years before it declines and eventually dies or root wash, plant it as a bareroot tree and enjoy it for years to come. I went with the latter. To do otherwise would be wasteful of both time and money.

Because my tree was container-grown in very loose soil, the root washing process was relatively fast. Root washing balled and burlapped trees (B&B) is more involved because most are grown in heavy clay because it holds together better in a root ball. It takes longer to wash from the roots, nothing a little soaking can’t accomplish.

If possible, pick a shaded spot to do your dirty work. The goal is to prevent the roots from drying out as you’re working. Here’s how I did it:

1. My tree was lightweight and easy to pop out of the container. B&B trees are heavier and may be slightly more difficult to lift into a wagon or wheelbarrow. Once it’s in, fill it with several inches of water. A B&B tree may need to soak for several hours to loosen rock-hard soil at the base. The soil around my tree’s roots fell away as soon as it hit the water. It was pretty loose so root washing didn’t take as long as it might with a B&B tree.
2. When things have softened, get in there with a hose and start rinsing away soil. Do it gently, teasing roots out with your fingers, being careful not to rip away any of the more delicate hairs.
3. Once the soil is gone, look for any circling roots and cut those away using pruners that have been disinfected with rubbing alcohol. You don’t want to introduce disease.
4. Leave the root mass in the wheelbarrow to soak while you dig your hole. Make it at least twice the width of the original root ball and the same depth. I always dig my holes slightly shallow to allow for settling and because my soil is so dense. It helps with drainage.
5. Before placing the bareroot tree in the hole, find the root flare. This is the swollen area at the base of the trunk where the roots begin. When you plant, the top of the soil should be level with the bottom of the root flare. Never cover the flare with soil or mulch.

Don’t amend the soil. Before I placed the tree in the hole, I added some Espoma Bio-tone to the planting hole for the benefical bacteria and mycorrhizae. It’s not necessary, but I do this with all my new plantings and it seems to work. Nothing’s died yet!

Before placing the tree, determine it’s best side. Every tree has one and that’s what you’ll want to see from your vantage point. Then position it in the hole and adjust the position so the flare is just above the soil line. A shovel handle or long stick layed across the hole is great for getting the level just right. Once you’ve backfilled it half way, firm it in gently with your foot. No need to jump on it. You simply want to remove any air pockets and properly surround the roots with soil so they won’t dry out.

Continue adding soil and firming until you’ve filled it to the proper height and water it in well with the water in the wheelbarrow. Don’t want to waste the benefical microorganisms in that water! At this point, the soil may have settled and you’ll have to add more soil. A three to four-inch layer of mulch will help with water retention. Just be sure to pull it away from the trunk to prevent any pest issues.

You may want to stake the tree to stabilize it until the roots have gripped the soil. If you do, leave them in place for up to a year then remove them. I haven’t staked my tree, yet. And I may not. It seems to be holding it’s own in a pretty exposed site. The most important thing at this point is water. For the first few weeks, you’ll want to keep those roots hydrated. After that, a weekly watering schedule should be just fine. When you do, water deeply so the roots reach low into the soil. Shallow watering encourages shallow roots and creates a weaker tree.

Still not convinced root washing is worth doing? Check out this article from Fine Gardening magazine. I feel better now that my Tina dwarf crabapple has been given the best chance at survival. Once established, it will be less likely to be toppled in a wind storm and more likely to thrive in my less-than-perfect growing conditions. Better to show it right from the start this ain’t Kansas anymore.