OK, so my dream project hit a snag. I unexpectedly ran in to some pretty heavy clay soil. I was able to mound up the plants pretty good, but a check of the beds today was disheartening. You don't have to travel too far away from the mounds to find some potential drainage issues. My "plan" is to work in concentric circles around each tree replacing as much of the clay with a better draining mix. This is a slow proces that could take many seasons (I planted too many trees!) so I am beginning with the side of each tree that is at the lower elevation (the bed slopes downward) so that the mound has a potential daylight. I have too many questions but if you happen to have any thoughts let me know: 1) Anybody want to share any "success stories" or other advice with the clay? 2) How far/how deep around each tree will I have to remove. In some places just a few inches seems to bring some soil that at least has some crumble. Other places, no matter how far I dig I just come up with stuff made for an art project :( 3) We mulch the beds each year. Will that eventually help amend the soil? 4) Any other commercial product that would help amend the soil until I can replace more of it? Thanks in advance
Don't see what the problem is - since this is the Maples section of the forums, I'm assuming you want to grow maples. Maples do well on clay soils, so just plant them in the soil as it is, no amendments needed. Just add some mulch (ideally old leaves) on top for worms to work into the soil.
Paxi, I have horrid clay soil and my strategy so far is raised beds. No amount of crumbled leaves will alleviate it, as my forrest will attest. Centruies of leaf accumulation and only a couple of inches of nice tilth - then you hit potters clay!! As Michael mentions, maples will definitely grow in this stuff (my property is swarming with wild examples that prove it) but from a nutrient/maintenance point of view I opted for the raised beds with nice, new, fertile top soil that I can actually work without using a pick-axe!! So I bring in TONS of top soil - TONS!! - by the dump-truck load. My back tells me its worth it. I think as long as your soil is not water-logged you should be fine. Acer rubrum will thrive in soggy soil, but JMs definitely don't like we feet. You say its on a slope, so chances are it should drain well. Are you seeing soggy, water-logged soil around your JMs? Oh yes, and I heard that adding sand is NOT an option. Sand + clay = the material used to make bricks = gardening DISASTER.
Thanks for the replies, and it is good to hear that it can be done. The section slopes well. Combining that with the fact that I hadn't run in to heavy clay anywhere else on the property, I was silly enough not to check soil conditions prior to planting. Yes the concern is that in several places (especially towards the base) water is visible in the mulch several days after a rain and the mulch even seems to be rotting in some places. While I can replace these sections with a foot or two of better topsoil I just wonder what happens after the maple roots exhaust this top layer. http://www.pacificcoastmaples.com/japanese-maples/planting-japanese-maple-trees.html What I have essentially done is the second picture from the following link, planting almost the entire root ball above ground. At the bottom however I also replaced a hole of the existing clay with my mix, which in retrospect probably was not a good idea.
Michael, That's a good point about top soil and existing trees. I made my raised beds 10-20ft. away from the established trees, and I made a barrier of small logs between the raised beds and the existing tree line. Its very important not to let the loose soil wash down around the existing trees. I lost a gorgeous (HUGE) White Oak years ago when I first started doing this because I didn't know any better. I had to have a tree removal service take it down at a cost of hundreds of dollars. Needless to say, lesson learned! So I've used this method successfully to get my raided beds and not endanger existing trees. I've also cut a few larger trees down to make room. Probably most important of all, I've started a program of SLOWLY raising the canopy on the larger trees. I take off maybe one or two lower limbs per year. This doesn't stress the tree and leads to better healing. The effect is dramatic! So much more light and air for the plants below, and it leads to a "park-like" effect which I think is lovely.
My last house had thick clay, a heavy slope and poor drainage between me and the neighbor. It had been cleared by the previous owner except for one large cedar which promptly fell over. So I, too, brought in (literally) truckloads of good soil. It was effective, to a point. My concern was that the clay would prevent drainage (I did loose one or two to bogginess) and that I might eventually grow my trees up only to have them fall over (like that cedar) when they finally got big. I know that turning the soil is no longer the thing because you let the worms and creatures do it for you, but I was concerned about them working fast enough to prevent slippage of the contrasting soil types (but again, this was on an 8% grade). I also got this advice from a buddy of mine (professional farmer from the area) who told me adding Calcium is a good way to break up clay. And that the BEST way to loosen up soil is to use Calcitic Lime. He said do NOT use Dolomite as your calcium source as it is high in Magnesium and that will actually tighten the soil. We didn't stay at the previous house long enough to implement his advice, but I respect him enormously. Based on his past successes, as far as I'm concerned, anything he says is practically gospel. And my mom's advice from childhood is to always throw in some bonemeal when planting (which is a good source of calcium). So for small scale planting I've been doing that for years, not knowing what made it helpful. Just intuitively I've added more organic material and bonemeal when planting in heavy clay soil. And maybe I'll find out this is wrong, but I try to mix my soil where the outer ring of the hole has a really heavy ratio of original soil to ammendment and the ammendment ratio increases on the way to the plant. I also use the shovel and/or the big bar to really score the outer ring of the hole before putting in the soil. I'm hoping that will help prevent the roots from circling. Which I started doing after someone told me that UW did a study where they dug up trees they had planted two ways many years later. One group of trees they planted in smaller holes without a lot of ammendment. The other group they planted in big holes with lots of ammendment. For the first few years the big hole group dramatically outperformed the other. But many years later the small hole group surpassed the big hole group. When they dug up the trees, the big hole group's roots had circled in the big holes. The big ammended holes had pretty much become large ground containers. Personally, I just can't not ammend the soil. I just can't. And I just can't put them in small holes. So that's why I try and graduate the soil ratio and why I try to make sure there are places where the roots can eventually find purchase into the sides of the hole. I hope I didn't just belabor the obvious, but I posted this because this was new information to me just a few years ago after having city gardened for years and then transitioning to a more rural location.