Compaction
Nothing grows in our yard and we were told that
it's because the soil is compacted. How can we remedy this?
Soil
compaction packs the soil and closes all the pores so water and air
have a difficult time permeating. Plant roots also find it hard to penetrate
compacted soil and so they will often grow along the surface. Compaction
can develop from many situations. If your house is new, chances are
the heavy equipment that was used to deliver materials and in construction
are to blame. Just walking on soil will compact it, so you can imagine
what an earth mover will do!
If equipment was the culprit, you need to have the soil plowed deeply,
to about two feet, then till in organic matter. If the cause is just
foot traffic, a simple rototilling should be enough.You can also relieve
shallow compaction by aerating, that is, removing plugs of soil and
breaking them up. The use of paths with shrubs or fences to deter shortcuts
will help control this problem, but the compaction will stay beneath
the paths. If you must drive on your lawn, first make sure that it is
dry.
pH
What is pH and why is it so important to have my soil tested for pH?
Technically, pH [p(otential of) H(ydrogen)] is a chemical symbol denoting
the negative logarithm of the hydrogen ion concentration of a solution.
It is used to express the relative acidity or alkalinity of a substance.
Acidity increases by a factor of 10 with each 1 unit drop in pH below
7, while alkalinity increases by a factor of 10 for each 1 unit change
above 7. So a pH of 5.5 is ten times as acidic as one of 6.5. On a scale
of 1 (acid or sour) to 14 (alkaline or sweet), 7 is neutral. (Aren't
you happy to know this?)
Anyway, most plants prefer the pH in the range of 6 to 7. Some plants,
such as rhododendrons and blueberries, like the pH a little lower, that
is, on the acidic side. Many plants, such as bearded irises and hybrid
delphiniums, like soil that is more alkaline, but just by a smidgen,
in the range of 7.1 or 7.2.
The kicker is that if the pH isn't in the range your plants prefer they
can't take up the necessary nutrients to be healthy. Some folks spend
small fortunes adding things to their soils but still end up with terrible
lawns or sickly plants. Our soil in Rhode Island tends to be on the
acidic side due to our climate but lime, which is ground calcium carbonate
rock, will raise the pH and sweeten the soil.
Have your soil tested at a soil testing lab, such as the University
of Massachusetts. By telling the testing facility what you are growing,
they can recommend the proper type and amounts of lime to use. They
can also test for important nutrients such as nitrogen, phosphorus,
and potassium (NPK), and they will tell you the correct amounts of each
to add, if needed.
Pasteurizing Potting Soil
I made my own potting soil from compost and such but how do I sterilize it to get rid of any bugs or contaminants?
Actually, you want to pasteurize it. By keeping the medium at a temperature of about 170 degrees F for one half hour, material from any pathogenic bacteria, fungi, and most insects and seeds will be destroyed. You will need disposable aluminum roasting pans and a meat thermometer. Place about 2 inches of soil in the roasting pans and put a meat thermometer into the soil. Set your oven at 200 degrees, put the soil in the oven, and start timing when the thermometer reaches 140 degrees; bake for 30 minutes. Don’t let the temperature go above 180 degrees as this will destroy beneficial organisms. If you have to adjust for temperature, remove the soil and let it cool before returning it to the oven for the timed period.
If you are positive there are no metal particles in your medium, you can use the microwave. A roasting bag does well (don’t seal it) as will a glass dish. Weigh the soil and, microwave 12 minutes for every two pounds on low power. Outdoor grills with lids will also work by following the oven method.
The smell is terrible, so be prepared.
Powdery Soil
My garden soil is very powdery and is always dry, even after rain or
watering. Why is this?
The powdery texture is the answer. Ever try dropping water onto talcum
powder? It beads up and rolls away. Your soil has no structure to absorb
water or air. It probably blows around on windy days as well. When it
does manage to absorb moisture, it compacts and you end up with a green
surface, right?
This is generally caused by too much rototilling and/or the addition
of too much peat moss. You need to add compost and perhaps a little
sand. Try not to walk on the areas where you plant and use a spading
fork to turn the soil. I can relate to your problem from experience.
By adding chopped leaves and compost, my soil improved greatly and the
rototiller has almost been retired. I also rely on shredded pine bark
mulch to help because it breaks down quickly.
Also, you should do a soil
test every year. Here in Rhode Island, we rely on the University
of Massachusetts for testing.
