In case the link is ever broken, cut and paste the PDF file here: Linda Chalker-Scott, Ph.D., Extension Horticulturist and Associate Professor, Puyallup Research and Extension Center, Washington State University The Myth of Gypsum Magic âAdding gypsum to your yard or garden will improve soil tilth and plant healthâ The Myth Upon continued prodding from one of my university extension colleagues, I recently watched several episodes of a well-known gardening program on television. My kids joined me, alerted by my animated responses to the hostâs non-stop torrent of advice. Among many amazing discoveries I learned that by adding gypsum to my yard or garden I would improve my problem soils by changing the particle size and loosening compaction. Further searching on the web revealed that gypsum would also improve drainage, decrease acidity, and eliminate soil salts. Previously, I had heard of gypsum for use in soil reclamation projects, but not for a typical urban landscape. Since gypsum is simply calcium sulfate, could this chemical truly transform soil structure and serve as a fertilizer for yards and gardens? The Reality This myth falls into the category of agricultural practices misapplied to ornamental landscapes. Gypsum effectively changes the structure and fertility of heavy clay soils, especially those that are heavily weathered or subject to intensive crop production. Gypsum also improves sodic (saline) soils by removing sodium from the soil and replacing it with calcium. Therefore, one can see improvement in clay soil structure and fertility, and desalinization of sodium-rich soils, by using gypsum. What other effects will gypsum have on soil and plant health? There are a number of scientific studies on gypsum usage both in the literature and on websites. Briefly, researchers have found: ⢠Gypsum does not usually change soil acidity, though occasional reports of both increasing and decreasing pH exist; ⢠Gypsum can increase leaching of aluminum, which can detoxify soils but also contaminates nearby watersheds; ⢠Gypsum can increase leaching of iron and manganese, leading to deficiencies of these nutrients; ⢠Gypsum applied to acid soils can induce magnesium deficiency in plants on site; ⢠Gypsum applied to sandy soils can depress phosphorus, copper and zinc transport; ⢠Gypsum can have negative effects on mycorrhizal inoculation of roots, which may account for several reports of negative effects of gypsum on tree seedling establishment and survival; ⢠Gypsum is variable in its effects on mature trees; ⢠Gypsum will not improve fertility of acid or sandy soils; ⢠Gypsum will not improve water holding capacity of sandy soils; and ⢠Gypsumâs effects are short-lived (often a matter of months) With the exception of arid and coastal regions (where soil salts are high) and the southeastern United States (where heavy clay soils are common), gypsum amendment is just not necessary in non-agricultural areas. Urban soils are generally amalgamations of subsoils, native and non-native topsoils, and - in home landscapes - high levels of organic and non-organic chemical additives. They are also heavily compacted and layered (and gypsum does not work well on layered soils). In such landscapes, it is pointless to add yet more chemicals in the form of gypsum unless you need to increase soil calcium levels. This nutrient deficiency can be quickly identified by any soil testing laboratory for less than a bag of gypsum costs. (If you need to improve sulfur nutrition, itâs wiser to use ammonium sulfate). To reduce compaction and improve aeration in nearly any landscape, application of an organic mulch is more economically and environmentally sustainable. The Bottom Line ⢠Gypsum can improve heavy clay soil structure and remove sodium from saline soils ⢠Gypsum has no effect on soil fertility, structure, or pH of any other soil type ⢠Most urban soils are not improved by additional gypsum ⢠Before adding gypsum or any chemical to a landscape, have soil analysis performed to identify mineral deficiencies, toxicities, and soil character ⢠Adding gypsum to sandy or non-sodic soils is a waste of money, natural resources, and can have negative impacts on plant, soil, and ecosystem health For more information, please visit Dr. Chalker-Scottâs web page at http://www.theinformedgardener.com.

Looks to me like the landscaper didn't do anything to improve the soil before covering it with the cloth and mulch - and so made a hardpack clay condition even worse. That water cannot escape because of the mulch cover and cloth cover. Solution - I agree with ixnod's suggestion on soil improvement. I've broken up clay matter by adding loads of composted material and also used builder's sand (fine sand will turn the clay into cement). I also did the job myself one hole at a time. Clay soil finally improved. With organic matter in place, the earthworms will also help in improving the soil. So in my opinion, remove the fabric, get going with the soil improvement. Of course move yoru plants temporarily for the winter (which means pot them up and imbed them in the ground, and mulch for witner protection) Once soil improvement is done, try to see why a landscape fabric was placed in the first place. For purely decorative reason? Or to help what is normally a dry spot or weedy spot?

couple thoughts ... with any soil ... what you need to master.. is proper watering ... and the problem with clay ... is learning how to deal with drainage .... and also ... trying to avoid it going bone dry in later summer ... to be clear.... as rhiz said.. there is nothing wrong with the clay itself .... for the plant.... in fact ... if you have ever seen any plant balled and burlapped plant of any kind ... what kind of soil would allow a giant ball of soil.. to stay in ball shape ... as its shipping all around the country???? ... well.. clay ... many of my OH friends with bad OH clay ... work on top of the clay ... adding good soil above... and basically making raised beds ... you mention tilling ... and that is not easily done in clay .... and that is why many peeps work above ... and the problem with tilling clay .... is that you MIGHT make adobe or cement .... it you add the wrong things ... finally ... being new to gardening.. try to find a local garden club ... meets some new friends... who know EVERYTHING about local conditions ... and many of them.. like to give away excess plants ... there is no reason to limit yourself to AL forums.... there is clay everywhere ... so .. you might want to look in other forums for other ideas ... perennials.... annuals.. trees.. shrubs... conifers.. etc ... you might also find your COUNTY extension office ... and talk with them ... they might have all kinds of local knowledge and resources .... and might know the local garden clubs ... have fun in the garden ... ken ps: do you know why we garden ... its the only justification an adult has ... to play in the dirt ... lol

Ella: Yes, same as "sharp sand" or "builder's sand" or "leveling sand" sold at Menards for $2 per bag, and at HomeDepot for $3.49 per bag. It's yellowish, very coarse. Play-sand is sold at Walmart, very fine, thus glue-up with clay. http://www.wisegeek.com/what-is-sharp-sand.htm "Sharp sand, also known as builders' sand, refers to sand that has a gritty texture. This type of sand is often mixed with concrete for a number of different construction applications. Sharp sand can also be added to soil in order to create potting soil or to loosen clay soil. In most instances, this type of sand is made from ground quartz rocks. " Prairie: Thanks for the info., really appreciate the time you e-mailed me the document on rose-breeding and blackspot strains .. that's to de-bunk the myth of Knock-outs with BS resistant-strains just to promote Knock-outs as the ONLY resistant roses. My experience: any vigorous roots would be disease-resistant, it doesn't have to be Knock-outs. I dislike false advertisement like that just to promote knock-outs, selling for $18 per pot, while other just as healthy roses being sold for $8 per pot. Val: I already answered those questions when you jumped into my thread while Kelly asked about her heavy clay. I shared in detail on how I used 12 bags sand for 24 tomatoes, with 1/2 bag of sand per planting hole, worked to depth of 12 inch, along with gypsum. I posted extensively about using coarse sand to break up heavy clay, starting in 2012. People falsely accuse SAND making concrete with clay, but people don't realize that THE TAP WATER THEY ARE USING is causing the glue-up. To treat tap-water and to deodorize, municipals use hydrated lime (calcium hydroxide), which is made from quick-lime, both compounds are used in making concrete. I notice that my Austin roses planted in partial shade, which I never bother to water, are 100% healthy .. versus those planted in full-sun with frequent tap-watering .. came down with blackspots. I dig up roses often in my garden, either moving them around, or they die after a harsh winter. The holes with frequent tap-water: soil became rock-hard, despite my previous breaking them up with organics like alfalfa hay. pine-bark, or coarse sand. Alkaline tap water at pH near 9 makes concrete out of clay. Hydrated lime is DIFFERENT from natural dolomitic lime. Hydrated lime is UNSTABLE, and it binds with potassium, phosphorus, and trace-elements, thus roses become pale, less blooms, and break out in diseases due to less potassium. and anti-fungal trace elements. That's why use sulfate of potash plus gypsum to de-activate the gluing-effect of hydrated lime. I sent my observation to Predfern, a rose-grower with Ph.D. in Physical Chemistry, and he sent me scientific studies to back up how tap-water glue clay into concrete. That's why I bought 3 rain-barrels and hooked them up to 4 garbage cans. The holes with rain water (pH 5.6), soil is fluffy, thus roots can get oxygen, leaves are dark-green and healthy. Thus the key of fixing clay is to DECREASE the % of fine-particle clay by INCREASING the % of COARSE matter, be it coarse sand, or coarse pine chunks, or coarse organic matter like alfalfa hay or leaves. The use of gypsum for alkaline soil is to cause clay particles to clump together in smaller chunks, allowing air to reach roots. There's a document that recommend the same, using lime for acidic clay, to break up clay into smaller chunks. I always use gypsum together with sand, its 17% sulfur or acidity and 22% calcium carbonate coat the particles, so they don't glue up together. P.S. I don't make up stuff just to impress, the info. came directly from the Soil booklet I got when I got my soil tested. Plus I double-check everything I read with Prefern, Ph.D. in Physical chemistry in my Chicagoland. I am an experimenter, and don't waste time in debating. I simply do it, and report the results.