Gene wrote:

Before readers go out and mix whatever sand they can get into heavy
clay, I'd like to add this. The crucial word in Gene's note is
"coarse." This means sharp, angular particles of various sizes. If
your sand comes from a low-elevation river deposit or worse yet from
a beach, it is likely to be too fine and the particles too rounded to
be a good soil amendment. Another crucial word in his note is "loam."
That is, the clay-based soil already has a fair amount of organic
material in it. If you mix sand into a really sticky clay, like
adobe, you'll get something that feels like lumps of chewing gum with
sand stuck to them. (I made that mistake in my mother's central
California garden once.)

After a quarter-century gardening on gritty upland soil, I recently
moved to a lower elevation and confronted heavy clay loam. Except for
the bulb house and rock gardens, where I created deep beds of coarse
sand and other well-drained components, I had organic amendments
tilled in deeply after the existing sod and trash shrubs had been
removed. My lilies and other moisture-tolerant bulbs went into the
prepared beds and, as Gene suggests, were mulched with a mixture of
milled compost and well-composted fine bark (available by the
truckload from a nearby supplier). I had the coarse sand brought from
the quarry that supplied my former garden: it's high up on a
rivercourse and is very sharp and gravelly. The extra haulage was
well worth it. The top 14 inches (35 cm) of the raised beds in the
bulb house is pure coarse sand, on top of about 6 inches (15 cm) of
clay loam with a little well-composted manure added. A woven
groundcloth barrier is below that. After planting the bulbs I mulched
the surface with pea gravel and quarter-ten crushed rock. Everything
seems to like this, but I have to add nutrients via soluble
fertilizer; they got their first spring feed yesterday.

I have been wondering whether to add more mulch to the main lily bed,
but am hesitating because I interplanted the lilies with hybrid
peonies. Can someone advise whether peonies tolerate an organic mulch
over the crowns? I have always avoided it. I suppose I could leave
the peony crowns uncovered, not difficult as they are under wire
supports, and just add mulch to the rest of the surface.

Thanks also to Gene for mentioning that late winter is an acceptable
time to transplant seedling lily bulbs. I have some crowded pots of
them that I should have dealt with last fall. I'll keep them in large
pots in a shaded area this growing season and plant them in the
garden next fall.

Jane McGary
Portland, Oregon, USA

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