Hello Gene, I don't dispute anything that you say, It is very good advice. However, my impression is that Rodger wishes to grow tulips in a rather sticky soil. If this is the case a basic principle of mixing compost is that to aerate the mix, or create drainage with coarse particles, there must be at least 30% particles (grit) by volume. Less will just embed particles in the clay. It is only when there are enough particles that they touch each other in order to create gaps in the soil structure that the nature of the soil will change. As you suggest an inch of gritty sand spread on the surface of heavy or good loam will achieve a friable soil which is free draining. I do this on rose beds in England -which reduces black spot enormously by allowing the soil surface to dry more quickley, (and encourages crocus, scilla, etc. to seed freely underneath them. For initial improvement of heavy clay or sticky soil I suggest that the top spit, (8 inches or a spades depth), be modified with 1/3 gritty sand, or grit. This also will bulk up the soil to create a mound or raised bed which may or may not be desirable in a given circumstance. It does take a lot of digging in! A WARNING -FOR ANYONE IMPROVING CLAY SOIL Digging a hole in a clay soil will create a pond when it rains, filling the hole with sand and compost will create a bog. Usually for such improvement a slope or raised bed is desirable. As you say, with really bad clay or clay subsoil, it is better to put a good depth of imported soil / sand / compost on top. I too have gardened on sand, loam, and heavy clay, in areas with rainfalls ranging from 20 inches to 100 inches per year and have been gardening for four decades. I was dissecting corms and bulbs, weeding Aciphyllas (-small hands get where larger ones can't!), aged three and had moved on from rooting stems of willow and sedums to trickier plants such as Nothofagus and Ilex by the time I was five. I am now 43. I was sending to Wallace and Barr and Bakkers for lillies - African Queen, Enchantment...., and my first tulips and reticulate Iris by the time I was 6. I was looking at scaling the lillies and scoring hyacinths and dafodills then. - nearly four decades ago. If only I had the opportunity to travel so far as Longview Washington area I should be be very glad to drop by, thank you for the invitation. Best wishes Peter (U.K. (England - Derbyshire, also gardening in Lincolnshire and Argyle in Scotland) On Sun, Sep 30, 2012 at 11:42 PM, Gene Mirro <mirrog@yahoo.com> wrote: > Peter, clay loam soil already has sand in it, and it also has silt. > Google "soil triangle". So you just have to add enough sand to turn it > into loam or sandy loam soil. In my very dense clay loam, 1.5 inches is > enough. If you are starting out with pure clay soil, such as subsoil clay, > I don't recommend trying to amend it. Either pile good soil on top of it, > or truck it off the property and replace it with good soil. If your native > soil will grow a good crop of weeds, it's probably good enough to amend > with coarse sand. I've gardened on the east and west coast, and I've never > seen soil turn into concrete because of the addition of sand. > > After four decades of gardening, I've gotten to the point where I refuse > to garden in heavy soil. I just do the soil improvement up front before > anything gets planted. I believe heavy soil is one reason why a lot of > people give up gardening after a couple of years. You can improve it > somewhat with organic matter, but it is a slow and endless task. With > sand, the improvement is immediate and permanent. > > If you are in the Longview, Washington area, drop by and see for yourself. > _______________________________________________ > pbs mailing list > pbs@lists.ibiblio.org > http://pacificbulbsociety.org/list.php > http://pacificbulbsociety.org/pbswiki/ >