I don’t know what area of the United States does not have predominantly clay soils, but it’s no where that I have lived. But that hasn’t stopped me from planting gardens and even fruit trees.
There are many important steps to take at planting time to ensure the good health and growth of fruit trees that this article will discuss, but the most important principle to successfully planting fruit trees in clay soil is this:
Fruit trees can be planted in heavy clay soils by planting the tree in a mound at least partially above ground level, which raises the roots above the ground water so that they will not drown during wet periods.
Here is the method I have used to successfully plant fruit trees in heavy clay soils in two different states.
Mulch Planting Area in Advance
Fruit trees are nourished through their roots and much of the important nutrition and water is actually provided through a symbiotic relationship with a type of fungus called mycorrhizae.
As far in advance as possible, prepare the soil where you will be planting fruit trees.
Lay down unprinted cardboard and a few inches of wood chips, straw, or raked up leaves. If it is not a wet time of year wet down this material periodically.
Naturally occurring mycorrhizal fungi is activated to begin breaking down this material. You can inoculate the material with this fungi, or let it come naturally. It will spread and begin creating a fungal network through the ground that will ultimately benefit your tree with greater health.
Dig the Right Hole
Once you acquire your tree you can dig your hole. Do not dig a hole too far in advance in clay soil or it will crust over .
The hole needs to be more shaped like a wide bowl than a deep bucket. It should be about as deep as the roots and 3-4 feet wide.
Score the sides of the hole vertically with your shovel about every 10 inches so that the sides are not slick and smooth. This will give the roots a place to catch and dig in to grow outwards and not in a circle.
Prepare the Tree Roots for Planting
If you receive the tree dormant with “bare roots” you should be prepared to plant it within a day or two. Do not let the roots dry out while waiting.
The roots re often packed with shredded paper or something similar. If it is drying out and you will not be immediately planting the tree, spray the paper with water so that it is moist, but not dripping wet.
To prepare the bare root tree for planting remove any shredded paper or other medium the roots may have been shipped covered in and submerge roots in a bucket full of water for at least one hour, but less than three hours to rehydrate the roots before planting.
Set the Tree at the Proper Hight
It’s most crucial that you plant the tree high in its hole.
I like to lay a rake handle across the hole to accurately gauge the hight of ground level, and make sure that the upper roots of the tree are above the ground level level.
Mound up some soil in the bottom of the hole to set the tree on at the proper height. Spread the roots evenly around the mound in a circle.
Backfill With Native Soil Only
Put the same soil you dug out of the hole right back into it. Do not add any extra organic matter.
Adding organic matter only creates an easy “path of least resistance” compared to the clay around the hole, which encourages the water to seep into the hole and drown your tree.
The only thing I add when filling in the hole are a sprinkling of Azomite trace minerals and mycorrhizal fungi.
Water in the Roots
When half the soil is back in, and once again when the remaining soil is back in the hole, gently tamp down the soil by stepping or pressing on it, and run water over the soil.
This will help the soil to settle and prevent air pockets which would kill your roots.
Mound with Amended Soil
After I have returned all the native soil to the planting hole there are still roots of the tree exposed above ground level.
Create a planting mound up around the tree with raised bed planting mix to cover all the upper roots. This is light and airy soil that will ensure you tree gets all the oxygen it needs and that you never have all the roots completely submerged in groundwater.
If you want to mix your own use one part each topsoil, peat moss, and sand.
Leave Graft Above Soil
Identify the graft union of your tree.
Mound soil over the roots and all the way up to the trunk’s previous planting depth (where the bark changes color). This should be about 2-3 inches below the graft.
Always leave the graft 2-3 inches above ground level.
Mulch Tree Mound
Mulch around the tree with wood chips or straw. The more aged the better.
Keep the much away from the trunk a few inches to avoid rot.
For the best health of the tree keep the tree mulched in its entire drip zone. Basically, however wide the canopy of the tree is–that is how wide the mulched are beneath the tree should be to help keep the mycorrhizal fungi for the roots happy.
Add Beneficial Plants to Create a Fruit Tree Guild
This is my Summerhaven Peach immediately after planting.
Here it is in its second summer after planting.
The tall buttery colored flowers growing underneath it are Yarrow which is a dynamic accumulator, pollinator attractant and used in bouquets. Behind the tree is mint, thyme and oregano, which are all pest repellants, edible, and pollinator attractants. To the right of it you can see a small rhubarb plant that is a mulching plant and edible. Also, in the spring this area had daffodils which are pest repellants and can be used in bouquets.
Further back to the right is our American Persimmon, surrounded by medicinal calendula. In the very back are some tall elderberry plants which are edible and medicinal.
Click here for my full planting list of beneficial plants in the orchard.