Date: Mon, 21 Sep 92 18:55:32 -0400
From: Bob Wildfong <bobw@csg.uwaterloo.ca>
Subject: Re: Sweat peas as ground cover?

In article <1677@lysator.liu.se> you write:
>My third question for today, I've been saving them up.
>
>In spring I sowed sweat peas _Latyrus odorata_ variety Knee-high. I
>had in mind to dig them into the soil in autumn (fall) to improve the
>abysmally bad clay I have instead of soil. But will it really work?
>
>How will the soil be next spring when I want to sow? Will the sweat
>peas really decompose until then? And what I worry most about, should
>I dig in the sweat peas and then plant the tulip bulbs over them?
>Isn't that asking for trouble? My garden is very small, in fact it is
>called a "patio" in the contract, so there is no other place I could
>plant the bulbs. Should I rip out the sweat peas and put them in the
>compost instead?
>

You might need to add more to the soil than just some plant material.
I've appended an old FAQ about soil amendment.  Hope it helps.
---
The two main qualities that you should look at in a soil are "texture" and
"structure".

The "texture" of a soil is essentially the range of sizes of the particles.
If you have relatively large particles you have sand, if you have tiny 
particles you have clay.  Drainage problems are almost always caused by a
lack of variation in particle size.  e.g. Sand has too much space between 
particles so it drains too fast; clay has almost no space between particles
so it drains slowly.  The best texture (and drainage) comes from a variety
of particle sizes.  This makes the soil hold water without being sticky.

The "structure" is the extent to which the soil particles stick together
to make clumps or "aggregates".  You've seen clay without organic matter in
it.  The particles do not form little clumps.  Neither does sand without
organic matter.  On the other hand, you've probably also seen rich, loamy,
fluffy soil (not in my garden, of course :-< ).  This soil has lots of
humus (decomposed organic matter), lots of tiny clumps of soil, and great
drainage.  Good "structure".

So, to get a good mix of particles add sand to your soil; preferably a
coarse grade to break up the clay.  Then to keep the soil from settling
into a thick mush again when it rains, add lots of decayed organic material.
Peat moss works well, but there are several environmental concerns related
to the harvesting of peat bogs.  According to a recent discussion on 
rec.gardens, peat bogs take hundreds of years to grow back and removal
of the peat drains wetlands and threatens nearby wetland habitats.  If you
can find a local source of leaf compost, rotted manure, or other organic
stuff, they will do as good a job as peat moss.  Better actually, since
peat moss has very little nutrient value but manure is a decent fertilizer.

Try for about 60% clay, 30% sand 10% organic material in the top 8 inches 
or so of soil.

Where I live, the city collects leaves in the fall and composts them in a
big pile.  You can get all the free leaf compost you can haul away.  I'm going
to put it on my garden 12" thick, let it turn to mush over the winter and
dig it in next spring.  Hopefully my soil won't have the texture of bricks
and the structure of pottery next year.  :-)