Many gardening activities are still a few months away. But some
things need to be done before spring’s sunny days arrive.
Compost, an excellent amendment for garden soils, needs to be
applied several weeks before seeding or transplanting.

Compost is decayed manures, animal litter, leaves and other
organic matter. More precisely, it’s the product that results
from composting, the process in which microorganisms convert
these organic raw materials into organic residues such as
humus.

Composting transforms the original manure, leaves, etc., into a
much more desirable and more valuable soil amendment.

Why Apply Compost?

Organic matter improves most garden soils because it:

• Supplies important plant nutrients.
• Helps soils better retain nutrient.
• Improves soil aeration.
• Helps prevent soil compaction.
• Makes water more able to move into soil and stay longer.
• Makes soil easier to work.

Why not use the noncomposted organic matter?

Weed-free, Pathogen-free

Compost and noncomposted organic materials both contain high
levels of organic matter. But only compost is free of weed
seed and pathogens.

Besides organic matter, manure and products containing manure,
such as animal litter, may also contain harmful weed seeds and
disease germs that can harm humans, plants and animals.

The heat generated during composting kills these weed seeds and
germs.

Holding Nutrients

Compost and noncomposted organic matter both contain essential
plant nutrients such as nitrogen, sulfur and phosphorus. But
compost holds the most nutrients in a leaching-resistant,
slow-release form.

Many of the water-soluble nutrients in animal manures may quickly
move into the soil and supply injurious levels of nutrients to
plants, or they may leach down below the root zone and no longer
be available to plants.

However, most of the nutrients in compost are in a complex
organic form and must be mineralized in the soil before they can
be leached or become available to plants.

For example, only about 10 percent to 15 percent of the total
nitrogen in compost is typically available during the first
cropping season.

Healthy Soil

Compost and noncomposted organic matter both contain many
microbial species. But the highest numbers and most diverse
beneficial microbes are found in compost.

Most gardeners are well aware of the old axiom, “Healthy soil is
alive.” That can be taken a step farther: “The more alive, the
healthier the soil.”

An incredible diversity of organisms lives in healthy soil. They
range in size from the tiniest one-celled bacteria, fungi, algae
and protozoa to the more complex nematodes and earthworms.

Soil organisms support plant growth as they decompose organic
matter, cycle nutrients, enhance soil structure and compete with
or in other ways inhibit the growth of harmful microbes.
High-quality compost is literally swarming with beneficial
microbes.

When? How Much?

Eight to 10 weeks before planting, broadcast the compost and
incorporate it into the soil. Small amounts are helpful, but for
the best results, the first application should be 20 to 30 pounds
of compost per 100 square feet of garden soil.

After that, annually applying 8 to 10 pounds per 100 square feet
should be enough.

Best Transplants

Many gardeners grow their own vegetable transplants. Growing
their own enables them to have transplants of special varieties
they couldn’t get otherwise. And it lets them have the
transplants when they need them.

Of special interest to those who grow their transplants, recent
research compared conventional transplant growing media without
compost to media amended with compost (20 percent of the
volume).

Bell pepper transplants grown in compost-amended media were
better transplants. They had larger stems and more roots. And
after being transplanted to the field, the transplants grown in
the compost-amended media produced 20 percent more peppers (by
weight) than the transplants grown in nonamended media.