I'm trying to get revved up for the weekend lawn job....
How's a good way to break up hard soil? Since it's all level, my first
thought is to soak it good for a couple of days. I wonder if renting
an aerator might also be good.
Most of the soil is fairly easy to dig down 2-3 inches, but about 1/4 of
the back yard is bare & hard as a rock. When I was taking soil samples,
I had to use a pick to get down that far. Good news is that the pH and
nutrients for the entire yard, including this bare area, were the same.
But the whole yard is dry and hard deeper than 3-4 inches.
How did it get so hard? Vehicles, traffic? Chemical composition?
How much time do you have? (Roots can do wonders)
How much area? (Is hand labor out of the question)
Is it worth doing?
My experience is that rototillers don't work - they just scoot over really hard soil.
Is your soil mostly clay? If so, try the following.
Broadcast enough gypsum over the area to coat the soil about 1/8 inch.
Lightly sprinkle with water, just enough to dampen the gypsum.
On the next day, water the area lightly, enough to start dissolving the
gypsum but not enough to rinse any away. Repeat every-other day until
all the gypsum is dissolved and rinsed into the soil.
Wait two days. Then dig. By now, you might even be able to use a power
rototiller. As you dig or till, stir a 6 inch layer of peat moss to a
depth of 12 inches; this will help prevent the soil from hardening again.
Note that this process is NOT a one-weekend task.
Gypsum (calcium sulfate) reacts chemically with clay to make it porous
and granular, thus breaking it up so that it can be tilled.
Unfortunately, it eventually leaches away, leaving heavy, sticky clay.
Thus, you will have to apply more gypsum periodically (every 2-3 years).
My lot is almost 1/5 acre, including the footprint of my house, the
short driveway into my garage, and a patio. Every other year, I apply
approximately 250 pounds of gypsum to my entire garden, front and back,
except for the steep hill at the far back. (I do not apply gypsum to
the hill because I paid a fortune to have it regraded and compacted when
it failed in 2005. Gypsum would undo the compacting and create the risk
of a new failure.) In the years when I do not apply gypsum throughout
my garden, I still apply it to my camellias and azaleas. Here (southern
California) gypsum runs about $9 for a 50-pound sack.
thought is to soak it good for a couple of days. I wonder if renting an a
erator might also be good.
the back yard is bare & hard as a rock. When I was taking soil samples, I h
ad to use a pick to get down that far. Good news is that the pH and nutri
ents for the entire yard, including this bare area, were the same. But the
whole yard is dry and hard deeper than 3-4 inches.
Without knowing what the composition is of what's there,
impossible to say. But if it's as hard as you describe,
a core aerator isn't going to work. It's made to penetrate
reasonable soil, not stuff that you need to use a pick axe on.
Someone said a rototiller will just walk around, so too will
the aerator. If there is non-existent decent topsoil, part of
the solution might be to buy screened topsoil.
Again, IF YOUR SOIL IS MOSTLY CLAY, you should treat it with gypsum
before trying anything else to improve its tilth.
From your description, I don't think an aerator -- even a power aerator
-- will work on the hardest parts of your soil without prior treatment.
After using gypsum, you will find that an aerator will work very well.
Just be sure you are using the kind that extracts plugs of soil (they
look like dog droppings) and not the kind that merely pokes holes. The
latter will cause more compaction and make things worse.
However, for a first-time treatment, I would recommend rototilling
organic matter into the soil after the gypsum treatment. This will have
long-lasting benefits. While I suggested peat moss, you should also
consider other forms of organic matter such as manure or coarse compost.
I would not add sawdust since it decomposes too quickly and absorbs too
much nitrogen in the process.
The slitter might actually make things worse by compacting the soil.
If your soil is like mine, there's a very narrow range of moisure levels
at which it's workable. I understand local farmers refer to it as "36
hour soil", which is the schedule window for plowing.
Too wet and it's like warm tar, too dry and it's extremely hard. In
the middle, it's rather crumbly. I'd soak a patch and poke it each
day after. _Maybe_ you'll find a day when it's workable.
Hereabouts this is called "Sunday soil", too wet to work on Saturday and too
dry by Monday. The problem with working it on Sunday is that it will always
stay the same, you haven't addressed the problem of why it is so hard on
If that is all you do it will not achieve much. Yes you do need to wet the
soil but then you need to alter the texture and enable to hold a good amount
of water by itself in future.
Gypsum and other clay breakers cause the clay to clump rather than stay
plastic. Organic matter lightens and loosens and allows organisms from
algae and bacteria up to worms and arthropods to live in it and assist.
Good soil is living soil not a bunch of minerals. You are aiming in the
long run for a good balance of particle size and particle type. If you
don't address the issues of the soils composition, texture and balance then
all the watering and physical breaking are just temporary measures. Good
soil neither needs nor benefits from frequent major cultivation although
that may speed up the improvement process at the start, doing it without
cultivation at all is quite possible but takes longer.
When you sprinkle just a small amount of water, does it soak in or bead
up? If it beads up, then yes you need a wetting agent. However,
detergent or soap are alkaline, which can further harden the soil
structure; so make it very weak. Use it on the gypsum. Trying to wet
the soil before applying gypsum will merely waste water.
I previously said that too. If it's as hard as he's describing, it will
just walk on top and not penetrate. It's essentially a weighted drum with
metal tubes on it. It relies on the weight to sink the tubes into the
soil, cutting out plugs of soil. If it's hard, those tubes won't penetrate.
I don't think it would make it worse. It doesn't go deep, all it would
do is loosen the soil near the surface. But if the soil is anywhere near
as hard as it sounds, IDK why he'd even be considering that manual thing.
They have power versions, called an overseeder, or slit seeder, etc.
But I don't think it would do any good either. At most it would rough up
the top 1/2" or so, while he needs to deal with several inches deep.
Then use a minor amount of liquid soap or detergent in the water AFTER
you apply gypsum. A 30 minute soak right now is excessive. It can
result in wasteful runoff.
A 30 minute soak right after applying gypsum will wash away the gypsum.
The initial wetting down should be less than a 5 minute sprinkle, just
enough to make the gypsum damp. The next day, a 5-10 minute sprinkle
will start the gypsum dissolving; do not sprinkle long enough to puddle
or start rinsing the gypsum away. (Sprinkling instead of flooding will
hasten the dissolving of the gypsum because of the force of the water
landing on it.) Then every third day, repeat the dissolving sprinkle.