A bed of pure sand, if wet in warm conditions, creates an ideal environment for (bacterial) rot in various plants such as Oncocyclus Iris. Rust in Alliums and Irids, and other fast acting pathogens. The capillary action in sand, which is so desirable in many respects, has the drawback of maintaining a humid, steamy surface when wet, and warm. A bed of pure sand, for many late spring growing 'bulbs', should have its top surface insulated against hot sun with a layer of gravel or stones, -or other material without a capillary action. (In my humble opinion) I have found that 'bulbs' which might be expected to need a dry Summer will grow quite well in sand which is wet in Summer. It seems that keeping the 'bulbs' cool when wet, and a substrate with a lot of air in it is as important as the dryness. Even so, 'bulbs' in dry sand for the Summer, (baked under glass in the UK) , often perform very well. Peter (UK) On 20 July 2014 04:20, Michael Mace <michaelcmace@gmail.com> wrote: > > > > >> Have you considered a sand bed? > > >> Clay soils hold more water, but less is available to the plant because > the water binds to the clay particles like glue. My raised beds are piles > of > sand and gravel, nothing else. The plants growing there require less > irrigation (in fact, none) than the plants growing in the heavy clay here. > > Wow, Bob. This is why I've subscribed to this list for so long. You guys > teach me things I never would have guessed on my own. > > > > At this point, I feel like I almost have to try a sand bed, >