Root washing before planting

In the past, I have planted various trees and bushes in my hard clay soil. In retrospect, things that grow best are those in bare root or in small 4" pots, usually through mail. Locally bought flowers in large 1/2 gallon or 1 gallon pots do worse. I feel part of the reason comes from the potting mix: its properties are so different from the native soil and roots have a hard time growing through the boundary. For small plant, the surface/mass ratio of root ball is higher so the problem is less severe. For big potted plant with many fine roots, even though I tease out the roots on the surface, the majority still can't grow out into new soil and die eventually.

On the The Garden Professors site there are several articles talking about root washing before planting burlapped or potted trees. Exposing the bare roots makes it easier to correct kinked or circled roots and the roots also make better soil contact. I feel that's the way to go so I root-washed and replanted a stunt rhododendron. I will see if it grows better.

Here is the photo of an oak tree grown in potting mix.  I found it in my local park and clearly it wasn't planted right. I tried filling some soil in the gap but months later the tree was gone.  I never know if it would've survived or not. If you buy such a tree, how would you plant it then?

I think in clay you are better off with a jagged hole.  If it's a cylinder the roots have trouble breaking out of the hole and into the surrounding soil so they just circle.  If you scar up the sides, or dig a star shaped hole, the roots can get into the big imperfections in the hole and escape into the wild.

If you pull it out of the pot and the roots are starting to circle, I'd cut through them with a knife so they get a chance to leave the root ball shape.

I had a tree that I planted poorly in clay and it didn't grow for 4 years.  I fixed it by just taking a shovel and vertically stepping it into the ground in line with the trunk of the tree (like the hands on a clock - radially oriented).  I aimed it to cut partially into the root ball and circling roots and partially out into the clay surrounding the hole.  I probably did 6 vertical cuts with the shovel.  It started growing that summer and took off the next year.

In the pic the center circle is the trunk, brown lines are the roots and black lines is the shovel cut.  All viewed from above.

Cool! That's much easier than digging it back up. I am going to try that on a slow growing smoke tree. It always leans sideway when the ground is soaked,  an indication something is wrong with the roots.

I like to plant trees as small as possible. Most of my coppice woodland was planted as less than 2 ft seedlings grown in root trainers. Even then I teased out the root balls a bit when they were planted into a square hole 2 spade widths across - no more soil amendment than turning the turf upside down in the hole.
Where I have planted larger trees, most have been bare root (apples etc.) although this year I have three pot grown grafted walnuts to plant. I will tease out the roots as much as possible and cut if necessary as Mike suggests. Probably a square hole as before, but since these are more precious (expensive!) I will definitely make sure they get a good mulch around them to keep the grass away for a year or two. They will also need staking so they don't rock and disturb the new root growth. I stake right at the base rather than up the trunk, so the trunk still flexes but the roots are secure. I might sprinkle some bone meal around under the mulch as well, to give the root growth a boost, since the trees do look a bit top heavy for the root ball in the pot.

My preference is small bare root plants also if I can find them. Potted larger plants seem to be the worst.

I wash the roots of every plant I get now and soak them in a bucket of water before planting.

The potting soil from potted plants seems to have a very negative effect if planted in the soil. The potting soil is created to drain extremely quickly to reduce rot for the contained potted soil. However, when put in the ground, it drains too quickly and the soil becomes super dry and the plant is much more susceptible to drought.

By planting dormant perennials and washing the roots and soaking them before planting, I've not needed to water them at all again after planting them, even in our intensely hot and often dry summers here.

Hi May,
This last year I have been adding fruit trees to my gardens. O.K. I probably should have put them in first before I made lots of garden beds all around my yard but I have a tendency to do things ass-backwards. Anyway, we can discuss my shortcomings some other time when everyone has enjoyed their fill of wine and are mellow. (homemade, I hope) I also check out the Garden Professors website every couple of months and I read the same article you did.

I planted several semi-dwarf cherry and peach trees last fall and they looked super healthy and happy and their grafts looked good but at the same time they were going dormant so what can I say, they looked normal. But I noticed that all the trees appeared to be pot bound by their roots. So I took the chance and sat them in a bucket of  water and kept hosing them off and loosened their roots and trying to make them feel at home. So, it's spring and they are leafing out; they seem very happy and they lived to tell about it. That's about all I can say.

This past month I bought 9 more fruit trees, pears, apples and plums (I spent the winter digging their holes) and they all looked super healthy and super pot bond. I got them just as they were leaving dormancy and some were beginning to leaf out. And again I sat them in a  bucket of water, used the hose to help me and loosened up their pot bound roots. Their roots were a huge tangle of big and fine roots going round and round. Loosening them up was like giving them a very firm massage and untangling hair at the same time. It took quite a bit of time. I was worried that I was killing many hundreds of dollars of very nice trees. But within just a couple of days they ALL began leafing out and the plums immediately started blooming.

So, all I can say is... I didn't kill them! They seemed to be very happy and healthy and I think I did the right thing! Will they grow to be spectacular trees? Well, if they can handle my Arizona climate.... I think they have a really good chance. And I agree with Steve, the soil they were potted in is not the soil they want to spend the rest of their lives living in. Happy gardening.

Thanks for the previous info... I have blackjack clay soil. We have 16 fruit trees in pots ranging from 10-25 gallon pots. They are root bound in these pots. So from what I'm reading above I will put them in buckets of water and tense out the roots . But do I remove all the soil?
Also what size hole would you suggest with this soil? Should we attempt to loosen it up as much as we can or just plant into the same size hole as the pot ( just a little bigger)?
Should we add compost of top soil. It seems that if we take all the soil off the roots, it would be hard to fill in the roots completely with this hard clay leaving air gaps around the roots? suggestions?
Being that its spring here some have many blooms and some fruit sets, should we just pull these off to helps the tree recover after planting?
Any other tips would be greatly appreciated!

Hi Denise, If I had known someone would like more info I would have taken some pictures while I was planting. But you can go to the blog that May and I were talking about for more info and pictures. Linda Chalker Scott has several posts on this subject. https://gardenprofessors.com/why-root-washing-is-important-an-illustrated-cautionary-tale/  Also on their website  https://gardenprofessors.com/ you can just type tree roots into the main page search box for even more info. And lots of people here have planted a gazillion trees. I'm sure they can give you awesome advice too. Just keep asking your questions.

I didn't actually use a bucket.  I didn't have one large enough. I wanted sort of... a small bathtub for these trees so I had lots of room to work. All the trees I planted were in 15 gallon pots and one was a 25 gallon pot so I just used a big plastic heavy duty tote that I had. 2' wide x 3' long x 20” deep. You might want to buy a big plastic or galvanized tub from your local hardware store. I pulled the tree out of the pot  and laid the root ball down in the tub on it's side. You don't want the bark on the trunk to get rubbed raw as your turning the tree so I placed an old pair of thick folded sweatpants under the trunk where it laid on the tote. Turn the hose on jet or full force right up against the roots and start washing. Once the tub is full of water you can turn off the hose and start massaging and untangling the roots underwater. You can't do one side and then another. You have to start from the outside and keep turning the tree and slowly working your way into the middle. It takes awhile so I sat on a bucket and got comfortable. I took off about 90 percent of the dirt. That seemed good enough. The roots were all free and easy to move around.

If someone has pretty good soil they could just dig their holes twice as wide and twice as deep as the pot the tree came in and be done with it. But I don't even consider my soil here to be clay. I consider it lots of rock and some pulverized rock/concrete. When I have finished digging my hole with a mattock pic and pulling out all the rocks there is very little dirt/concrete stuff left so I have to amend my soil with plenty of organic matter. I mix a 2 cube bag of organic OMRI certified soil with my little bit of  Sedona dirt (the tree has to get used to it sooner or later), mix in the dirt from the pot and add some compost from my pile. (Compost gives them nutrition and lots of good bacteria)  I mix in a little organic fertilizer and some sulfur because the dirt and the water here has a very high ph and plant the tree.

Now, I have heard some people recommend that you plant your trees right in your native soils. They surmise that the tree has to get used to it sooner or later and this way.... only the strong ones will survive. I don't think any of them live in Arizona red rock country. But it does sort of make sense. But I figure these are very young trees, just toddlers so to speak. And I would rather give them a helping hand until they're a little bit older and tougher and stronger before they have to fight their own battles. And if you do it right.... they will amaze you!

And Mike mentioned that it might be best not to make a round hole so the roots don't circle around again as though they are still in a pot. Perhaps a jagged hole would be best. That sounds good too. But my main gardens are in my ¾ acre backyard protected by a 6' chain link fence. I've planted many trees and shrubs in my unprotected front yard and the deer just devoured them. However, when I dug them up to move them out back I found that they were sending their roots out into my Sedona dirt/concrete  everywhere. They were tough enough and old enough that nothing was going to hold them back! But I still like his idea.

I always put an 8-10” berm around the hole with Sedona dirt (which will turn into concrete as soon as I shower it with water) and rocks and plant the tree so it is 3-4” higher than the surrounding area. In a year or so all the dirt in the hole will naturally compact and settle and the tree will end up being 3-4” lower than grade. Then I cover each one with 5-6” of shredded leaves as mulch. The leaves hold in a whole lot of moisture so I only need to water the tree once or twice a week for the first year or two (even though it goes to 115* here in the summer) and leaves always brings the worms (gotta have the worms, they're awesome gardeners) and lots of great fungi. Cover it with rocks or chicken wire to hold the leaves down. Lots of organic matter, good nutrition, good bacteria and fungi seems to be the winning ticket!! And I would leave all the blooms and the leaves alone. Don't make the tree worry, it should just be happy.... being a tree. Anyway, I've planted a whole bunch of trees and shrubs here and they all seem very happy. Again, lots of people here can give you great advice about planting your trees which might be better and easier than how I do it. Happy gardening and welcome to Permies.

Denise supkoff wrote:Thanks for the previous info... I have blackjack clay soil. We have 16 fruit trees in pots ranging from 10-25 gallon pots. They are root bound in these pots. So from what I'm reading above I will put them in buckets of water and tense out the roots . But do I remove all the soil?
Also what size hole would you suggest with this soil? Should we attempt to loosen it up as much as we can or just plant into the same size hole as the pot ( just a little bigger)?

Late to the party, but we have been using this method successfully for 30 years, in heavy clay and sandy soils:

- Dig a hole roughly twice the size of the pot
- Break up  the subsoil, mix with crude black soil and a handful of bone meal, add water and stir
- Rough up the roots so they are sticking mostly straight out (they can't be growing in a circular fashion, or the tree will fail to thrive) ; leave existing soil in place
- Mix additional crude black soil with some compost and the leftover potting mix in the pot (some add a little more bone meal, as long as your dogs won't dig it up)
- Fill the hole a little at a time, packing as you go
- Ensure the tree crown is at ground level, not too high and not too low; adjust as needed
- Soak the planted root ball completely, several times; if the tree leans to one side, put a shovel under the root ball, lift, and pack in soil to compensate

Douglas Alpenstock wrote:

Denise supkoff wrote:Thanks for the previous info... I have blackjack clay soil. We have 16 fruit trees in pots ranging from 10-25 gallon pots. They are root bound in these pots. So from what I'm reading above I will put them in buckets of water and tense out the roots . But do I remove all the soil?
Also what size hole would you suggest with this soil? Should we attempt to loosen it up as much as we can or just plant into the same size hole as the pot ( just a little bigger)?

Late to the party, but we have been using this method successfully for 30 years, in heavy clay and sandy soils:

- Dig a hole roughly twice the size of the pot
- Break up  the subsoil, mix with crude black soil and a handful of bone meal, add water and stir
- Rough up the roots so they are sticking mostly straight out (they can't be growing in a circular fashion, or the tree will fail to thrive) ; leave existing soil in place
- Mix additional crude black soil with some compost and the leftover potting mix in the pot (some add a little more bone meal, as long as your dogs won't dig it up)
- Fill the hole a little at a time, packing as you go
- Ensure the tree crown is at ground level, not too high and not too low; adjust as needed
- Soak the planted root ball completely, several times; if the tree leans to one side, put a shovel under the root ball, lift, and pack in soil to compensate

That's funny Douglas, I do almost exactly the opposite  I have very heavy clay soil, and I never amend it at all.  I dig the hole and make cuts in the side, like Mike mentioned.  I rough the sides up really well to make it easier for the tree roots to penetrate.  I usually dig the hole with a digging fork because it doesn't compress the soil on the sides of the hole and make it slick the way a shovel does.  I only fill with native soil.  I want the tree to know how to grow in the soil it lives in now, and I don't want, as Paul Gautschi puts it, to "lie to the tree".  If I mix better soil into the native soil, the tree has no reason to want it's roots to leave that better soil and venture out into the relatively worse native soil.

Once the tree is in the ground, I put cardboard down around it to keep down the competition while it is getting established.  I leave the cardboard out a foot or so from the trunk to make sure rain can get in.  Then I mulch heavily with wood chips.  Any amendments go on top of the ground for the worms and rain to move down into the soil.  Support plants are put in after, and almost never with any real plan in mind.  I just put in what I have available.  I almost always put a ring of daffodils around my trees, and a much large ring of comfrey, and then I fill in between with onions, mint, herbs, whatever else I have or want to have.

Just goes to show, there is no one right way to do things.

You can wash the soil off, but to protect roots after it, you may want to use liquid (sour-creal like) mud. It is a common practice.

Fizpok Pak wrote:You can wash the soil off, but to protect roots after it, you may want to use liquid (sour-creal like) mud. It is a common practice.

This is an interesting idea. I'm thinking you meant sour-cream - as in consistency? By dipping the roots in a thin mud they will be sure to have good soil contact and it will protect them from drying out. Thank you for your comment - it might be common practice, but I for one hadn't come across it!

Fizpok Pak wrote:You can wash the soil off, but to protect roots after it, you may want to use liquid (sour-creal like) mud. It is a common practice.

I'd like to learn more about the details too.

Is this practice more common among commercial growers? I don't see it mentioned in any home gardening books I read.

Occasionally I ran into a purchased plant that needs to be root-washed for repotting.
Here is a recent one (or five).

I wish I had taken picture of a gaura plant I once had. It came in a gallon pot that I later planted in ground. It grew bigger in one season and gradually died away. I dug it up and found the plant was strangled to death by its own roots around the crown. It seemed that the nursery rooted a cutting in a tiny pot and repotted root bound plants into bigger pots until it reached gallon size without correcting the circled roots while young. I learn to check the roots closely when shopping in stores.