Fruit trees in clay

[slackdaddy]

I want to plant some dwarf fruit trees (plum, apricot, cherry, pear) but my soil is clay with about 6" good soil on top.
I can add about another 6" of good soil to the top in this area.
but below is solid clay, takes 2-3 days for a test hole to drain down.
What is my best approach for planting dwarf fruit trees in this area ? Raised beds ? how big ?

Nick

[egon]

Are there naturally growing trees in the area?
That might give some indication of growing and planting possibilities.

Egon [img]/forums/images/icons/grin.gif[/img]

[eccentricfarmer]

That does not sound that good, i am willing to bet you will have to have enough there for the tree to survive at least one year (dig a hole and such) to get the roots to set in, ever thought about plastic ones and go into the pottery business?

[slackdaddy]

There where oak trees (red, white)
this area was cleared woods, and HEAVILY disturbed from the building process. The excavation spoils pile was here, all clay.
I did put about 6" top soil over it after rough grading.

Nick

[egon]

OK, sounds like you have an experiment on hand.

I'd suggest that you use a post hole auger[ hand operated] to dig down about three or four feet deep were ever you wish to plant a tree and fill the hole with good soil. Also around each hole dig down a foot or so for about three foot diameter and fill this area with good soil and then plant your trees.

Note: This is not a certifiable procedure but something Egon might do and has done but in pure sand. It did work for Egon but your case might be different. [img]/forums/images/icons/grin.gif[/img]

Egon [img]/forums/images/icons/grin.gif[/img]

[Pat]

Sorry Egon, buddy, but I have to disagree... If you dig a hole in clay it doesn't matter much what you put in it it will fill up with water and the roots will drown/rot.

I have done something similar but dug a grid with a DitchWitch. one pass wide for each parallel or intersecting ditch and planted the larger items at the intersections. The difference was the bottom of the ditches drained down slope. So if the miniature orchard is on a hill you could get drainage and trenches interconnecting the holes for the trees could have drainage.

A raised bed, it only has to be a few feet wide (as wide or wider than the canopy/dripline of the mature tree), works pretty well. I used raised beds for dwarf citrus and other fruit trees where I had soil that just didn't perk. Until the trees are established and for an indeterminate time after you may have to irrigate the trees. The raised bed needs drainage so don't totally enclose the perimeter with an impermeable barrier like laying concrete blocks or whatever.

Over time the roots may penetrate a ways into the clay, at least a little, and they may find moisture enough to reduce your irrigation requirements.

Pat

[slackdaddy]

Pat,
How high does a raised bed for dwarf fruit trees have to be?
like I said, I have 6" of good soil on clay now.
No real slope to the area to drain away.
Yea, the last thing I want to do is make a "bowl" to drown the trees.

Nick

[Pat]

Depends on the tree to a large extant. How deep do the roots go with mature trees of the type you want to plant? If for example a mature tree had roots down 24 inches then 18 inches or more of soil above grade (added to the 6 you have above clay will accommodate the tree nicely. Of course a little less depth will likely work but at some point as you would reduce soil depth more and more you will be getting reduced noticeably performance.

This is not exact science. Roots of some cultivars may, in time, penetrate into the clay. Some of my Kumquats, Loquats, Lemons, and Oranges did OK with about 6-8 inches of topsoil above the impenetrable layer (up to grade) and another 16-18 inches of raised bed. I outlined the raised bed with broken concrete from a slab I demolished with a sledge. The courses were staggered and due to rough nature of the material did not seal at all well so drainage out the sides was well supported, at least down to the top of the original grade.

Pat