az sher
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Location: glendale,az

heavy clay soil and grapefruit tree

Hi, I just got a 15 gal ruby red grapefruit tree. I dug the hole larger than the pot(15in). My intuition said to see if it would perk as I ran into clay about 8 inches down. It's a good thing I listened to me. 6 inches of water took 7hours to perk. I guess that is not good.
QQ How deep should I dig down??
QQ Will the tree be strong enough to get through the clay?
Thanks for any help.

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rainbowgardener
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That's not great, but it's not terrible. Heavy clay tends to drain 1/2 inch an hour. Good soil drains anywhere from 1 -4 inches an hour. Sand drains faster than that.

So your soil is heavy and slowish draining. You will want to amend it with lots of compost and organic matter.

In the meantime, welcome to the forum. Since you posted the question, I am moving all this to the tree forum, where more people will see it who can give you more suggestions about how to help your grapefruit tree.

az sher
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Location: glendale,az

Thanks for the encouragement. I bought a post hole digger to help me get deeper, but how deep do I have to go? I have other soil with some decayed leaves in it to put in the hole. Logic tells me that the tree will eventually get through the clay because I have seen trees split rock in the mountains, but I really want grapefruit, so does anyone have experience with this?

JONA878
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Hi az sher

The general rule when planting any tree is to plant at the same depth that the tree was in the nursery or growing pot that it came in.
You should be able to see that level on the trees trunk.
Newly planted trees require a stake to stop them from rocking until they have established good rooting.

Clay soils are a nuisance in one way and a blessing in another.

First they do not drain well.....so plenty of organic matter and grit at the bottom of the hole.
Make sure that when digging the hole that you don't smear the walls as this creats a ' flower pot ' effect which the roots have to battle through. Break up the wallls and bottom as much as possable.

The good thing about clay is that it retains moisture and clay coloids hold on to nutrients well, stopping easy leaching.

Once the roots have settled they will penetrate the clay ok providing you can prevent excess waterlogging.

Jona.
An apple a day.....keeps me in work.

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rainbowgardener
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So that means you want to dig a hole deeper and wider than your root ball and then fill it back in with amended soil, so that your tree still sits at the same level it was. But that gives it some inches of loose soil to draw from before it hits the clay. And as Jona said break up the bottom as much as you can so there's not a hard line between the new and old soil, but the new amended soil is blended into the bottom and sides.

az sher
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Joined: Mon Dec 28, 2009 10:02 pm
Location: glendale,az

Thanks for the info. I am out there digging with the post hole digger and will go as far and wide as my energy holds out. The old lemon tree 25 ft away and the large Chilean Mesquite tree are doing good, I guess there is hope. We were full time rvers so did not have yards before.

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applestar
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Location: Zone 6, NJ (3/M)4/E ~ 10/M

I have solid clay under just a couple inches of sod. I've found that most trees and shrubs don't do well for me if planted after digging down and amending the soil.

So my strategy is to lift out the sod/turf, thoroughly fork and fracture the clay subsoil, add a layer of half finished, unscreened compost, including sticks and earthworms, return the sod chopped up into chunks grass-side down, sprinkle some pea gravel and a thin buffer layer of the mound soil mix on the sod-bottom-clay, put the rootball of the tree/shrub on top, making sure to loosen the roots (tucking longer roots in between the sod chunks), then mound a mix made of up no-frills clay-y topsoil (unamended but better than solid clay) from elsewhere in the garden, screened finished compost and some sand. In other words, I plant the trees on mounds.

Depending on water requirements of the tree and the lay of the land, I leave a shallow swale on the upslope side of the planting to sequester water for the drought we always have in the summer, and if necessary, raise a slight mound on the downslope side to hold water (broken or solid quarter circle~semi-circle). Otherwise, water can drain away right along the top of the clay subsoil and leave the mound dry.

As I finish the mound, I fork the area and lay wet cardboard in a circle surrounding the tree to sheet mulch, then mulch and stake the tree two-, three-, or four-way as necessary.

So far, this method has produced good results.

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