2 Responses

1. theManicGardener

   May 22nd, 2008 at 10:24 pm

   1

   I’ve dealt with this both personally and, ahem, professionally. In other words, I have horrible clay soil myself, and I’ve researched this as part of my job writing about organic gardening.

   I wrote a LONG comment to you this morning, but my computer had a hissy fit and died, so pardon the point-form version:

   –Raised beds will help with drainage.

   –Dig in as much organic stuff as you can—compost, but also peat moss or, even better (because it’s a renewable resource), coconut fiber. Mature compost is always best; among other things, it is the food for worms, which themselves deposit the best compost, and whose tunnels help aerate and irrigate heavy soils.

   –be aware that both peat moss and coconut may lower your soil pH (esp. coconut, which has a pH of about 5.5), so you may need to use some dolomitic lime to re-establish a balanced pH. Depends what your soil pH was to begin with—in the eastern US, where there’s a lot of rain, soil tends to be acidic, so you might well need the lime in Florida; in the west, soil tends to be alkaline.

   –Sand, gypsum, and other products are sometimes recommended and sold as amendments to help “lighten” clay soils, but there are warnings and caveats for each. I don’t have extensive experience here, but I’ll pass along what I’ve read. In brief:

   –sand seems the obvious thing to add, but since a number of good sites warn that adding sand to clay creates cement (uck), be careful. (I read this just after I’d incorporated A LOT of sand into a couple of my beds, so I’ll be able to report by summer’s end whether I had cement and whether anything grew in it.) I’d do the following: first, don’t use sand without a lot of organic matter as well, and second, use “sharp sand” (sometimes written as one word), not smooth river sand or possibly impure industrial sand.

   –Whether gypsum helps depends on details about the sodium levels in your soil and the exact type of clay involved. I don’t yet follow all the ins and outs, and wouldn’t want to try to reproduce it all here, but it sounds as if you’d only want to use gypsum in a dry area on alkaline soil.

   –Mulching isn’t mentioned on any site I’ve consulted about this issue, but I’ve noticed that beds covered with row covers don’t get nearly as crusty and hard as open ones. I’m going to see if mulching helps preserve the friability of the surface soil.

   Good luck with all this!

2. Webmann

   May 23rd, 2008 at 8:50 am

   2

   Excellent comment, that’s a lot of helpful information.