Many times you will hear that before planting anything in soil amend it with lots of organic matter, but in clay soils if you do that you essentially create someplace where water can flow into freely and then cannot move out easily, so amending the soil just around where you will be planting is not something you want to do. If you can amend a very large area around where you will be planting that would be good, but you do not want to create a "bathtub". Test your drainage by digging a hole 1 foot in diameter and 1 foot deep and fill that with water and allow that water to drain away. Then refill that hole with more water and time how long it takes to drain. If less then 4 to 6 hours you can add lots of organic matter to the planting hole, but if more than that, while organic matte is needed, it is better to lay that OM on the soil and allow the Soil Food Web to move it in, a process that takes much longer but gets the OM into the soil better than tilling.

As I said, some will claim you are a tree killer for planting a sugar maple in unholy clay no matter the evidence your present them, they just ignore it. Like growing by the thousands in the local heavy clay to a very large size. The the mound is only to help get them established, so they don't sit in a basically a bucket of water, while the roots then find the right level for their roots to grow in, same as if it is loam. The mound is 8-10 inches tall, and the tree trunk will end up a couple feet across and will far surpass the size of the mound. The roots will grow naturally at the proper level. They will find the same level in the soil no matter how they are planted to begin with. IF the right depth is one foot, then they will grow to one foot depth. If they start 6 inches above that, then they will grow down to one foot. They will not grow at 6 inches instead of 12 inches. If you look closely at many larger established trees, there will be evidence of them being planted on a mound, but the scale of the mound is such a small fraction in comparison to the overall size of the tree, it's not noticed unless you look for it. As far as whether it really is heavy clay or something similar to clay but not really clay. Take a look here. ftp://ftp-fc.sc.egov.usda.gov/NSSC/Soil_Taxonomy/maps.pdf for a nation wide soils map. The local soils are of the order Ultisol which are ancient heavy clays. This also includes far Northeast Oklahoma which katrina1 has said in other posts is the area of her location. For information of Ultisols look here: http://en.wikipedia.org/wiki/Ultisol And more specifically at my location the specific Ultisols that the thousands of large mature natural and planted sugar maples which are no evidence that sugar maples can be planted in clay and do well in real clay are "Ck-7" and "Jo-4". But alas, to some it matter not. Some soils/environments sugar maples will not survive, or at least not prosper. Some will require some special attention at the start, as transplanting is not a natural process, and is akin of having open heart surgery, therefore special care is only reasonable. Some clays may not be suitable. However to imply that your site is unsuitable simply because it is clay is ridiculous and unfounded. All the thousands I see around me must simply be a dream. What a beautiful dream it is. katrina1 do whatever you want. I was simply trying to make you aware of what has been successful for me and it a recommended method (BTW this method originated from the Minnesota extension service I think, it's been too long since looking it up). Just google "planting trees in clay soils" to find similar instructions. It works, and is recommended, and that's all the evidence I need.

I assume the soil has poor drainage due to the clay content. I have hard packed clay soil in my yard and I planted my trees on a mound and everything is growing nicely so far. I amended about 1/3 of the soil with a mixture of compost and top soil. Compost will decompose after some time and your plant will drop down so be sure to plant it several inches higher than where you want it to be in a couple years. The organic amendments in Topsoil will also decompose and cause your plant to drop but there are also inorganic ingredients in Topsoil that will not decompose. I highly recommend planting on a mound. I have heard that Mango trees thrive in poor soil but I preper to add some organic materials into my planting mounds so that water will sink into the soil. If you plant on a mound of only native clay soil, water will run off the mound. If you plant on a properly constructed mound, there is little worry of overwatering. Simon

g'day daleblack, better late than never maybe hey? but here goes. first questions (as i have never used brunning gypsum), was the gypsum of a moist talcum powder type consistancy? second if yor soil is like it sounds why fight it? use raised beds for all gardens, if you wanted to you could do a raised bed first where the trees are going then plant the trees in to rasied bed, the main thing with trees is their feeder roots need to be well drained the tap root will pretty much find its own way. so for trees that need good feeder root drainage you need to plant them into a raised position that is you dig a slight hole into your original soil throw some good quality gypsum in (usually the best stuff is bought at a produce agency) then create a mound to what ever height you need over and above that to plant the trees into (might be anywher up to 1/2 the heith of the current root ball?), this is necessary with citrus in those heavy soils so you may get some clues from researching planting citrus trees. len Here is a link that might be useful: len's garden page