Hello again - another question :) So we're transforming our small garden space in the front yard into a dwarf JM garden. Yesterday we completed phase one by digging up the plants and grass that was there, tossing in some mulch, etc. We planted one of our trees, an abigail rose, and we noticed that about 8-10" down we ran into clay. How much depth do dwarf JM's need in order to thrive long term? I plan on adding some more mulch but without doing some serious modifications I can only give them maybe 12-14" of clay free soil. *edit* after reading through a bunch of threads it seems to be the consensus that JM's can thrive just fine with clay soils. I live in rainy Seattle so there is lots of wetness to contend with but I've never seen this area get water-logged so that leaves me hopeful. Am I worrying for nothing?
Hi, Niroha, If you have clay soils (like me), the best (and probably only) solution in your case, is to plant your JM in a raised bed. Clay soil keeps the water for too much time, and your JM will drown fast. JMs don't like "wet feet". You need to povide it a very good drain soil or improve yours to be sure that water flows well. Believe me, I lost several specimens here for this reason. I attached some pictures (taken 4 years ago) from some of my planted maples and they're doing very well. I installed a underground drain pipe around the border of these raised beds to allow runoff excess of water. Nelran
How much of a lift then? The clay soil is about 8-10" down and I've already added several inches of additional mulch/soil. Is this enough for dwarf JM's?
Japanese maples are not deep rooted You probably have enough depth of soil as it is. If the ground has never been waterlogged you may well have sufficient drainage already Like Neiran I have made a practice of planting my Japanese maples almost on top of the ground and then building up the soil around the roots I think if you adopt that practice you will have no reason to worry Best of luck
Here in Tennessee, where we have nothing BUT clay soil - and nasty clay soil at that - I plant all my JMs 12" to 24" above the original soil level in raised beds.
Not an expert here, but I can tell you that I have Ultilisol Clay soil (very eroded, and VERY clay) that most anything will grow in as long as you don't have some sort of bowl effect. You did not mention other than grass, what you may have been digging out. But assuming it's not a wetland species, then you almost certainly will be fine. The fact that grass was growing indicates that there was adequate drainage, and you likely have little to worry about as long as you plant properly. Plant on a small mound if you would like, it certainly will do no harm. Most of our trees (shade) are planted on mounds 6-8" above grade, and up to about 4' across to help establishment. They are doing very well. Arktrees
In our wet winter, dry summer climate, clay 12-14" down should be fine for JM. Ours have thrived in heavy silt loam underlain by clay.