Are you mulching?

Cal: It is the gray description that concerns me most. Gray means the soil is very poorly drained. But the material underneath sounds better. Guess I would think about removing the gray material and replacing it with good topsoil or planting mix. Would do this when planting new trees. This would allow water to penetrate into the lower material which sounds better drained and is hopefully more permeable and better for root growth.

The Fruitnut

I was told that Figs like clay, not sure about pure clay though.

@Cal

I know that soil all too well. You can forget about growing fruit trees in that soil. Its impenetrable and the nutrients are quickly bound up due to the alkalinity. Even citrus(which I tried) was a complete failure. There is a reason that those hillsides were covered with scrub before the developers scraped away every inch of topsoil. Thats why developers love eucs in SoCal. Which they plant by the truckload.

The only solution is to excavate and replace. Mulching exacerbates the problem by retaining moisture and leading to root rot.

Sorry for the dire prognosis, but I spent a lot of money battling that soil.

I have pure clay soil, but raise almost every fruit tree possible in my zone and then some. I have learned to make a mixture of clay with potting soil or serious organic matter, but not to dig too deeply into the clay or it will act like a bucket and hold water and kill the plants. I almost plant the tree on top of the ground surrounded by the clay and potting soil mixture. There are some plants however that don't seem to mind the clay that much. They are as follows: Persimon, ogechee lime, che grafted on osage orange, jujubee, mulberry, muscadine grapes, pear. I have over 100 fruit trees and wish I had better soil. I helped a friend plant a few trees about 4 years ago in good loamy soil. They grow twice as fast as the ones I have and are much healthier, but when given lemonds make lemonade.

I also have clay-like soil in my backyard. I know too well about the bucket effect described by george. There are two things you may try besides excavating the whole yard.

1. Loosen the soil of the planting spot. Use gypsum to chemically break down the clay.
2. Use good soil to build a dune that is 1 or 2 feet high. Plant the tree on top of the dune. Your tree will be benefitted by the better soil and improved drainage.

Good luck.

Avocado trees seem to do just great with little maintenance here. I'm going to have to cut one down in a few days that a renter planted in a corner of the property a few years ago, right up against the foundation. No watering, no mulch, and only about a square yard of visible dirt, the rest concrete. but it's huge now.

I used to have an apricot tree, here, too. I'm not sure what variety it was. Came with the house. It was messy but very productive, and, again, received no special care.

My problem isn't drainage, we are in the middle of the worst drought in recorded history right now, only two inches of rain total in the last eleven months. I live on a hill so any rain I do get mostly runs away downhill. One thing that seems to work for me is after I dig a planting hole I make a cone of pure pea gravel inside the hole and plant the tree on top of that, then refill the rest of the hole with a mixture of clay and compost. If I don't use the gravel and instead use amended soil when the compost decays the soil level goes down and my tree ends up with the grafting union below the level of the surrounding dirt. I then make a berm on the downhill side of the tree to keep water from running away downhill.

If drainage is not a problem then you probably have a nutrient issue. As stated before, the alkalinity of the soil is binding up the nutrients. You stated that your fig tree has only grown 3 inches in 3 years! I don't know what is normal but mine put on at least 2 feet of growth every year with very little fertilizer. I still think you may have some type of Phytothera root rot which run rampant in those soils and sucks the vigor out of the plant. People who have never lived in SoCal have no idea how gross that soil really is. But look on the brightside, this year is probably not a good year to start a orchard anyway. As there will be no water to give them. Water rationing starts May 1.

I have had good growth with my Red Haven Peach tree in clay. I dug a big hole, and mixed in a bag of planting mix. Very good growth, but only 9 months old so far. I plan to dig in more mulch each year, and create "donut" shaped mounds around my trees. I have had good luck with peaches in many soils.

Ron Wagner,
Decatur, IL

the clay is not nearly as big a problem as the caliche. and digging a hole with a jack hammer will in a sense just be creating a pot, which will leave your trees water logged with no drainage. You would be much better off using raised beds for the planting area.
Note: another way to deal with caliche is to scrape all the soil off that you can without having to jack hammer. then buy several gallons of pool acid. pour the pool acid onto the caliche and let it sit over night or longer. The acid will slowly react with the salts that form the caliche and will loosen the soil enough that you can dig it. repeat until you get to the depth you want.
Ultimately, a good mulch a foot thick will help too. It takes years for the mild acids from mulch to penetrate any significant amount of caliche. In the mean time, however, it helps a lot with the clay soil, for those things that can grow in shallow soil.

My soil is not quite as bad, but is similar. The way I deal with this is to start everything in five or fifteen gallon pots with quality potting soil with perilite, adding water polymers. When the trees are big and bursting out of their 15 gallon pots, they can be planted in a raised bed, four trees to a 4Âx 4Âbed. Or just keep them potted, and move them up to larger pots. Be informed and fussy about the rootstocks you choose. Find out which is recommended for your area.
Start thinking now of recycling gray water from the bath tub and washing machine, being careful about the soaps, shampoos, detergents you use. Save the cold water you have to run until the warm water starts, and use that for watering also. Urine is flushed every third toilet use, with used toilet paper going in the trash. Or get a compose pile started, and "give back to the earth". Droughts are the norm here. WeÂve dealt with them before, and can again.
I have had apricots, avocado, cherries, pear, plum, grapefruit, and grapes that love our soil, for all its problems. Just donÂt over water.

I live in san diego's eastern suburbs, and have fairly heavy clay soils as well.... the problem i have at the moment is that my wife wants and avocado tree, lemon tree and a lime tree in the backyard, after reading up on these trees it seems she has picked the hardest trees to grow in this area due to poor drainage and soil type, however what the wife wants, the wife gets.... So rather then buying the plants and have them die on me, im in the process of terraformng the backyard... every square inch of it (1/4 of an acre), which is a long, painfull and exhuasting exercise. But nothing that is worth it was supposed to be easy!

With all the caliche here in New Mexico I've discovered that I need to dig huge holes - ensuring I've got them very deep for drainage and then backfill the hole with caliche-free topsoil mixed with a really good compost, adding humus and Super-thrive as I water the new plant in. I have experimented with soil sulpher both here and in Arizona, and, even though I know it is recommended, the chemistry that occurs in the soil does not support its use. What you're trying to do is to neutralise the alkalinity and change the ph to a suitable plant-supporting level - in other words, create a micro-soil for your plant to grow in. Removing the caliche is the best way to do that. If the layer of caliche is too deep to remove it all and its likely the plant's roots will enter that level it might be worth considering a plant that is either very shallow-rooted or one which is adapted to the alkaline soil. I am now in the process of creating a soil environment for blueberries at 7000 feet in caliche-layered soil - I'll let you know how that works out.....

albert1 -- how did it work out?

I've established an orchard in blue-grey clay by bringing in a huge quantity of sand and compost for each tree and blending a soil of a part each (by volume) of sand, clay and compost going a couple inches below the soil line and rising about a foot above in raised beds of about 6' diameter circles. The clay actually makes managing the trees easy here in the humid northeast. The roots can't penetrate the pure clay much and the trees were precocious with about the ideal level of vigor.

Figure on about 10 cubic feet of sand and compost each per tree. Blending in the clay is what is really difficult.

I still manage the orchard and it's been about 12 years- plums, pears, peaches, apricots, cherries and apples have all done well. Generally plums and pears do best in poorly drained soils.

IME, adding compost to clay is a great idea.

Adding sand is basically making concrete.

First of all a little background. I am a graduate of Cal poly Pomona, I am a licensed irrigator in California and Texas. I also own a tree farm in Texas . White Hall Trees. In texas we do not have gray clay we have black clay that is at least as bad as what we had as a kid in California( I grew up in Orange County) Now with that said.

The problem that everyone seems to have is the same. You claim you cant get fruit trees to grow in clay. Being a Civil Engineer, Landscape contractor and LI for 30 years I have some basic recommendations.

First Clay is an excellent way to hold water ! and fruit trees need water! But not so much as to be wet all the time. First raise the tree about 3" above existing grade. When planting dig the hole twice as big around as the pot and 3 inches shallower than the pot . When back filling around the pot use a 3/4 to 1/4 ratio of good composted material to the clay and Float the tree back in. Simply put add water to the soil to get out air. Then ad 3" of good hardwood mulch around the tree.

The biggest problem that you have is water so call Ewing Irrigation or John Deere landscapes and get some Rainbird .26 Drip tubing on 12" centers and drip the trees! If you circle the tree with lets say 6 drip emitters and water for 10 minutes you water .26 gal of water. Lets say the tree needs 3 Gal of water per week in one hour you will water 1.56 gal of water. So water 2 hours per week ! You may need to water Tuesday and Friday for 1 hour each day and check the tree hole with a moisture probe you can buy at one of the local Home depots for about $ 10.00
The biggest deal is don't guess ! Test and check ! Make sure. If you need more than 3 gal of water per week they have drip tube in .26, .4,.6, and .9 Netafim, Rainbird, Hunter, and Landscape products all make drip tube ! Do the calculations and if you are unsure call an irrigation professional they can help. The guys at Ewing can also help if you ask and by the way if you bring donuts to them they even get nicer !!!!!!!!!!!! Try It !

Marty and scott_home are right on the money. You CAN grow in this crap! I do. One side note to add: I never put a dwarf tree in my clay. You need an aggressive root system to bust through this stuff...and that defeats your purpose.

Jopparich, I believe you are quoting the literature without considering the possible caveats. Yes, adding too little sand can make the problem worse, and the reason the literature constantly repeats this danger, I think, is because they aren't talking about amending a very small chunk of soil for a relatively small tree.

What I proposed most definitely will not create concrete! The stuff I started with on the project I spoke of was almost the same as what potters use and I'm sure could be used for the purpose. The soil created with the recipe I supplied is very nice stuff that has already supported healthy trees for over a decade and they were planted as bearing age trees which are much more susceptible to poor drainage and other stress than whips while establishing.

As you probably know, the difference between sand, clay and silt soils is primarily the size of the particles (although the minerals that become clay tend to be different than those that stay sand)- add enough larger particles and you can transform a clay.

This is easy enough to do when you are only talking about amending a yard or two of soil. That said, it's lots of work to thoroughly blend blue clay with anything- it will stop most roto-hoes. However, if you go to the trouble, the trees may be more drought resistant and better anchored than if you simply pile on a coarser soil into mounds above the clay.

It may not be the best solution- especially where you are dependent mostly on irrigation- the other offered here might be, but it is a reasonably practical option, IMO.

The brown clay here has the typical "rock-hard when dry/ stick- mushy when thoroughly saturated" features. During drought times, the cracks can become 2" wide on top and more than a foot deep. I imagine that the shallower, weaker plant roots can get torn apart as the hard, dry clay encapsulating them contracts dramatically. A neighbor lost 14 very large, old pecan trees 3 years ago following Summer drought. Some eighty feet tall. No shade from tall weeds, bushes, mulch,or anything else.Two acres of non-irrigated clay. Hot, sunny, rainless months. Hot, dry, massively cracked, sunbaked clay........About 100 yards away the fruiting trees/vines/bushes here had a good year of growth, and not one tiny or huge tree died. Making a mound of good organic soil mix on top of undisturbed clay is the planting choice for me. As the fruit trees grow, the mounds are enlarged. The clay below each mulched mound does not get sunbaked, dried out, or cracked, but remain moist enough to encourage the roots to enter as they chase the moisture and descending nutrients. Since the roots themselves grow down into the moist clay, the undisturbed clay will not become a dug-out soup bowl that fills and stays full during rainy weeks.

CWC, that is interesting, but I wonder if that would work in all clays. If the pecan trees that died were able to establish roots in it in the first place it probably is not as bad as it can get and I can see how your trees were able to anchor in it- but because I haven't tried your method in blue clay, I can't really critique it one way or the other.

I have tried using a back hoe to break up compacted soils to create planting holes and have had a terrible time with tipping trees during strong winds when the soil is saturated, although the trees grew well. If the trees do fail to penetrate the native soil this might well happen with your method.