Clau soil particles are a mineral and do not "break down", it is the organic matter thaat gets mixed into the clay that gets digested by the soil bacteria. Some types of clay do not seem to allow organic matter to mix, there seems to be some kind of barrier at the soil/mulch interface that prevents mixing so those soils need to have some organic matter tilled into the soil first. Once that is done then mulches add to the OM in the soil with no problem. However, wood chips and shredded bark seem to be the most common types of mulch material that presents this problem. I would find some good compost and work that into that soil first and them apply the mulch.

I had clay at my last house...everywhere. Really makes you appreciate nice black soil. This may be a long post, but I have a lot to say. In hindsight...and my main bit of advice to you...I should have spent 3-5 years (or however many years it would take) amending the soil before planting (anything, not just hosta)...and I should have spent the time, $$, and effort to amend the ENTIRE planting bed, OR...raise the beds way up high with good soil. Here was my big mistake...I only amended the hosta holes just where the planting hole was. I tried to go farther out & when I did it wasn't very far...a few inches maybe. Digging the bare minimum hole in clay was hard enough, ya know?...AND...hostas grow on the driveway, right? Growing on the driveway would be easier than in clay IMO. If the clay had any workability, I would throw away the clay chunks and mix anything workable with compost. The clay easily 'ate up' the compost, so in a year some of the hostas would sink down into their clay holes and have to be lifted due to not enough soil. Because of this, "tending" to my hostas did not mean walking around & enjoying the plants. It meant regularly monitoring the health of the plant, and digging/replanting. When I dug up and re-planted it meant amending the soil all over again. Spent a lot of money on bagged compost because I couldn't make enough to keep up. If I would have dug a huge honkin' hole & amended really far out from the hosta, I think I would have had a few less worries. Doing it the way I did, my hosta were more susceptible to squirrels and other surface-digging pests. Everything was clay and it was hard. Come up to a hosta...softer & squishier soil than everywhere else...you bet they are going to dig right there. Root sections would be exposed and/or displaced to the surface. Squirrels would plant walnut and buckeye seeds within inches of the crowns. I'd dig out walnut shells regularly. Disturbing roots is always a setback to some capacity. When I dug out a hosta and some roots made their way out of it's amended hole and into the clay, consider the new roots 'goners'. Soil was too hard & sticky to allow roots to release with the rest of the plant. The clay was so hard to dig, that attempts to excavate the new roots in the clay were not even worth it. The water issue was not pleasant. Because I dug out clay in plant spots only, visualize the planting bed like a muffin baking pan. Where does the water go when you pour it on top of the muffin pan?...it spreads and lands in the divots. Once the water was in the divots, it would disperse into the surrounding clay, but pretty slow. I was on constant watch for root rot because of that and lost a few. I also learned that I had to regularly water the entire planting beds and keep the clay lightly moist at all times. I had a moisture meter, and I was constantly digging experimental holes to see what the moisture was like below the surface. When clay dries out it's like a brick...literally...and repels water. Keeping clay slightly moist will allow it to take in more water...but there was and art and science to keeping the moisture at a good level...never too wet, never too dry. I remember I used to pray for NO rain because it was easier to water myself and keep my system going. Didn't want Mother Nature messing with my water schedule. I hope I'm not a downer to your day. I'm listing out problems & maybe you can come up with your own way of dealing with potential problems & know what to look for if your hostas are not thriving. I did grow hostas in clay, and many did quite well but it took a lot of work & learning. I'm thankful for my experiences with clay, but even more thankful my 70-year old current house doesn't have clay. Gayle ________________________________________ Gayle gave great advice, I wish she had posted it 5 years ago when I started gardening in clay, I would have followed every instruction to a tee. As it stands, I spend a lot more time improving the soil in new planting areas than I used to - I foolishly thought a lasagna bed could be ready in 1 season. Whn you have clay - it is easily 3 - 4 years before you have "good" soil unless you do a lot of tilling and amending along with the lasagna method and then tilling is defeating the purpose of trying to lasagna the easy way LOL! So anyway, yes, clay is a horror to garden in. Plan on watering a LOT even when you just got rain or it is about to rain but be cautious about it becoming water-logged. I actually lost hostas that were in the ground in an area I thought would be okay because they were in standing clay slop for part of last year. Good-bye Ocean Isle and Phantom, two I really terasured, because the clay was too wet. :-( If I ever decide to move, number 1 priority at new house will be decent soil, which means I probably have to wait until my kids are in college since school has moved to a distant second LOL! Alexa ________________________________________ ________________________________________ Sun, May 30, 10 at 9:21 I also have pure clay under the first four or so inches of topsoil that was added when my house was first built. Every garden that has been added here started with a major soil renovation. I dug out 12 to 16 inches of the clay, hauled it away wheelbarrow load by load and then backfilled with dozens of 40-pound bags of top soil, compost and some peat moss thrown in for good measure, tilling it all up to a wonderful mixture. A lot of work, but has paid off tremendously both during the initial planting and in subsequent years, as I can easily remove, add, move plants without having to dig new holes and amend soil. About five years later, I got smarter and realized that I could have accomplished the same thing by simply pulling off the sod and adding the layers of top soil, compost and peat moss above ground, using my usual rocks to form the edges. Duh! Last year, I decided to expand the section on the south side of my house. Unfortunately, my gas line runs right through this section, and I was unable to do any substantial digging or tilling. And since it was next to my house, going up was not an option either. So I compromised by digging out (yes, I had the gas line marked first) very large areas for each hosta - about 2 to 3 feet across, depending on the mature size expected for each plant, and 2 feet deep. Then I backfilled with my usual mixture. My hope is that the holes are large enough to allow the roots to grow to their desired state without hitting the clay. It's year two, and so far things look okay. But I added a few ground covers this spring and had to deal with the clay in those spots, so adding plants will be very difficult going forward. And I will be on the lookout for the types of issues that Gayle brought up. Again, this would not be my recommended approach but was necessary due to constraints of the specific location. Good luck - clay soil is a beast. ________________________________________ Sun, May 30, 10 at 18:46 Maybe a photo of your soil will help the more experienced folks give a seasoned opinion. It was easy for me to know that my clay soil would not support any plants for any length of time - red, hard as a rock when dry and very heavy when wet. A clear line where the topsoil ended at 3-4 inches and the clay began. No signs of earthworms. My soil renovation was a lot of work, but when completed allowed me to plant immediately. Given your description, it sounds like your soil may be in better shape, so maybe you can avoid having to go that extent. Here's hoping that's the case! ________________________________________ Just FYI, I had earthworms in my clay too. The presence of earthworms is not a good indicator on whether clay soil is gardening-friendly. I would take the info presented and just be aware of what happens with clay...make adjustments necessary for your site. I find as long as I'm aware of the worst-case scenarios, I can always know what to look for and be pro-active. Thanks for the nice comments about my post. That yard was definitely a learning-lab for many different things. Gayle ________________________________________ Mon, May 31, 10 at 8:44 Melissa, I have soil similar to what you describe. My gardens for the most part are/were 12 to 18 inches of very heavy black clay and topsoil. When I started gardening here 10 years ago my next door neighbor, who had been collecting hostas for 25 years at that time, offered me a dozen large (wheelbarrow sized) mature fortunei, ventricosa, sieboldiana, montana, lancifolia, and divisions from older named varieties, to make room for new introductions. He was in acquisition mode big time, so I got a wonderful start on my gardens from him. I planted them like gayle0000 did, making (albeit huge,) hosta-sized holes, improving the soil in the planting area, digging another huge hole, etc.. From digging those holes and wrestling the hostas into place with the help of my then-teenage son and his buddy it was more than clear that the soil needed a lot of help. Over the next many years until now I did a sort of lasagna gardening (without knowing it was that), spreading bales of peat, mulching 4 to 6 inches deep with shredded oak leaves every fall, covering bare soil with newspapers or cardboard topped with bark mulch to block weeds, tossing the coffee grounds around the gardens, spreading compost around and between the planted hostas, and recycling my homemade potting soil every 3 years into the gardens. It has made a remarkable difference in the soil over time. Whereas we literally needed a pickaxe to start the original planting holes, now I can relatively easily (for a 60-year-old) dig a new planting hole with a transplant spade and lift pretty large hostas with a 4-prong fork. If I could start over, I would remove the clay soil, double dig each bed, raise the bed level, and start with good soil, which I did last summer when I removed two beds of perennials-run-wild to plant new hostas. Still, those original hostas are giants now and the soil around them is plant-able with little need for amendment, in the areas that I improved from the top down. ________________________________________ Mon, May 31, 10 at 12:16 My gardens were all nearly unworkable clay when I started in 1998. Today, they all have beautiful, workable soil. I used TONS of compost...I bought humus in bags from Walmart, it's cheap and worked great. It was backbreaking work double digging all of those beds, but the effort plus time took care of the clay. Any time I re-planted an area, I would take the time to incorporate more humus or compost...it made every job big. There was a soil conditioner that was very expensive which I found at Bachman's in 20 or 40 # bags. I believe it made a HUGE difference, probably even more/faster than the Humus. It was in the 3rd or 4th year that I re-dug my gardens and mixed it in...I was really getting tired of that clay! Probably mixed more humus in at the same time, knowing me. My gardens got overgrown and were unmanaged the 5th and 6th year, as I was ill. When I went back to working them again, I had beautiful, friable soil that is now a pleasure to garden in. Very occasionally, I find a hunk of clay, but it's usually near an edge of shrubs or something that didn't get worked much with the humus or the soil conditioner. Bachman's has a good article on working with clay...to their credit, they don't try to sell you the conditioner and state that the jury's still out on that. I think it worked wonders, but since I did a lot of humus, too, it was probably the combination. And, somewhere along the line, I think I put gypsum in there, too. Gypsum is usually quite cheap. For the conditioner, I'm not sure if the brand was Shultz, or not, might have been Turface (Profile) or something else. In fact, I think the Turface people may actually sell the product to Shultz. bachman's link: Here's a description of the Shultz product, I nabbed it from the Amazon site for you: Instantly improves any soil! Turns hard-to-work clay soil into a loose, rich growing medium - permanently. Adds thousands of storage spaces that hold air and water in nearly perfect balance in the soil. Clay Soil Conditioner improves drainage and aeration in heavy, compacted clay soils and helps improve water and nutrient retention in dry, sandy soils. Made from 100% natural fuller's earth, this unique mineral is kiln-fired creating ceramic granules that work to improve soil structure. Just one application lasts year after year! Clay Soil Conditioner? is a stable mineral that will not break down or compact over time. Use at the rate of 15% by volume: (1 part Clay Soil Conditioner? to 6 or 7 parts soil.) Here is a link that might be useful: another review for soil conditioner ________________________________________ Tue, Jun 1, 10 at 0:54 I have clay soil. I started with 3 hostas, and just amended the holes. After 3 years, didn't see much, if any increase on the hostas. Then one winter I was going crazy and ordered a bunch of hostas online. I decided I wanted to have great looking hostas, not just so-so. So I pulled out the hostas that were already there, expanded the bed, and rototilled in lots compost and some peat moss. I can't believe what a huge difference it made. The hostas are growing great since they don't have to try to expand their roots into rock hard clay soil. The 3 hostas I already had really took off - they were finally happy! I've read many threads where folks say that tilling is unnecessary; just place the compost on top of the soil and let the worms work it through. However, I had tried that and it didn't work. I ended up with the top 3/4 inch of soil being nice, with rock hard clay underneath. Tilling is the way to go. Deanna ________________________________________

I've used buckwheat as a cover crop for almost 40 years and it does not have any noticeable "allelopathic" qualities. I like it for breaking up clay soil in particular because I can usually get at least 3 crops in in most climates. I broadcast seed the first crop, then when the seed has ripened I mow it and let it self-reseed. I leave it lie. Do not dig in. This works great to break up hardpan if you have it which you probably do. However a quicker method that is almost as good in the short term and maybe better in the long term is to switch to deep mulch. In an urban/suburban or desert environment where hay and other agricultural products are in short supply (if not actually unobtanium) is to switch to a cardboard mulch covered with whatever you can lay hands on in the way of good bark mulch. I used to be able to buy bagged mulch from Home Despot or Lowes that was sort of appropriate but this year all they seem to be carrying are the dyed products that sometimes contain pressure treated wood, plus there's the actual dye. That stuff will run and stain concrete, I don't want it in my garden. So right now I don't have any suggestions on where to get your bark/wood mulch because *I* have lost all the sources I've been relying on. Anyway break down plain brown cardboard boxes as are used for moving or shipping (not cereal boxes!) so they are flat, dampen them, and then lay them down on your also-damp (but not sopping wet) soil. Cover that with whatever you can find in the way of bark mulch to a depth of about 2 inches. This will cool the soil and allow worms and their buddies to start to do their work. They will pull that cardboard down into the soil over time, mine's been down for 2 years and there isn't much left of it. This will loosen the soil and and fertility. Your plants roots will do the rest. The cardboard also acts as a weed barrier while this is going on. Just cut a hole in it to plant your plants. Leave a large enough opening in the cardboard so that your drip emitters (you are using drip irrigation, right?) can dispense their bounty onto the plant's roots. Keep in mind the entirety of the root zone, don't just water next to the stem. You can pull the semi-permanent wood mulch back and add cardboard from time to time, but I've not seen a need to do that. I do garden on a much smaller scale these days, but this has worked well for me since I've moved away from more rural areas where better stuff like hay is available for mulching. Eventually your wood mulch will also start to break down and you will need to add to the top layer from time to time. By the time the second season rolls around your soil will already be obviously of better tilth and fertility. I found not a single worm anywhere in my beds the first year. They're about as common as I found them to be in the much wetter and less sandy midwest soils I grew up with now, here in a desert environment. Been in this location 2 years this month.

Someone here is having good results with amending clay with 50 percent sand and then topping the area with sandy loam. The nurseryman who runs Laguna Hills Nsy and gave the soils class takes the stock he buys and removes most of the mix around the roots. Then he replaces it in peat moss, perlite, pumice,sand and some charcoal. He would add more sand in the mix he sells bagged but the bags would rip or be too expensive to ship. The charcoal is there because the world's best soils have some charcoal content. A building supply in Costa Mesa sells something called Rick's mix that is sandy loam and decomposed granite for improving clay. I have used the best potting mixes I could buy and watch the plants die off in a year. With the mix from Laguna Hills, it doesn't happen. Now I use a mix of my own soil, sand and the Laguna Hills formula. I have been making charcoal all winter and sifting it to throw out the ash which is alkaline. In the old days the nurseries planted in Sandy loam and sold bareroot. No one amended the holes or they planted high in large mounds or raised beds if drainage was poor. Now the wholesalers who planted in real soil are being edged out by those who plant in composted wood. The plants grow fast and are lighter to ship but eventually the breakdown of the planting material kills the plant. You can slow the process by letting the mix dry out almost completely before watering again, but it stresses the plants, especially in our warm climate. In the old days, a nursery could water every day with no root problems at all. A nursery could keep their stock for years and water every day and feed once a month until it sold. Now it's a race to sell the plant before the mix degrades and the roots die. The nurseries have to move their stock quick before then. Even if you plant it in good soil, the plant might not make it to five years because the mix around the trunk has become poisonous to the plant. Some plants grow fast enough to get roots out beyond into good soil. Arborists use augers to drill out holes around the trunk and backfill with sand to get the oxygen into the toxic area. You can also dig into one side and replace with 100 percent soil and six months later do the other side. The formula is stay away from three times the diameter of the trunk when removing roots. That was the formula for moving plants sold in soil wrapped with burlap. Any plant you fix needs to be shaded for two weeks. You can also help them by spraying the leaves with 1 gallon water 1 oz Karo syrup 1 oz seaweed 1 oz fish fertilizer a little wetting agent I hope this helps anyone trying to save a plant. I think it's rotten that plants are being sold that they know will have problems later on. People think it's their fault. The landscape reflects the trend towards only plants that can overcome the crappy potting mix and we all get taught wrongly to add this stuff to the soil at planting time.