Building Soil Fertility

“The Nation That Destroys Its Soil Destroys Itself.” Franklin D. Roosevelt, 1937

 Key to a Great Garden is Great Soil:  Building Soil Fertility

by Mary Stauble

Keep on improving your soil - Here are some things to do:

• Compost your organic yard waste and kitchen scraps.  When you need large amounts, buy it from Solid Waste Management in Charlotte-Mecklenburg County or another reputable landscape supplier.  

• Use organic mulches—shredded leaves work great.  

• Reduce erosion in your yard.  

• Grass-cycle your grass clippings.  

The best organic gardeners get excellent results and have gardens to die for!

Many organic gardeners see compost as an alternative to synthetic fertilizers that do not really benefit the soil.  A more middle-of-the-road view is that compost and fertilizer are best used to complement one another, since compost increases fertilizer use efficiency by hanging on to nutrients.  This is especially true with annual vegetables and flowers.  Annuals are more energy intensive, generally needing more nutrients and water.  They live short fast lives.  Vegetable gardens, especially, need more nutrients.  In addition to annual applications of up to 3 inches of compost dug or tilled into the soil, many organic gardeners add an organic fertilizer such as chicken manure, feather meal or rock phosphate, so the veggies get the nutrients they need.  

Organic mulches are also great for the soil.  They reduce annual weeds, keep in soil moisture, moderate soil temperature and reduce erosion.  

Mulch should not be applied too deeply—two to four inches is generally enough.  A few plants such as Bearded Iris should not be mulched.  Eventually mulches of pine straw or nugget mulch will break down and add organic matter to the soil.  The nutrients are minimal, but they do help improve soil texture.  

Ecological gardeners have deep respect for soil and work to build up soil fertility.  They compost their organic yard wastes and kitchen scraps.  

Good compost improves drainage of heavy clay soils, buffers pH, helps hold onto soil nutrients, improves soil texture and supplies a variety of macro- and micronutrients.  

Compost-rich soil is great stuff.  Research also indicates that plants grown with compost tend to be healthier as certain soil-borne diseases are suppressed.  Compost is the life preserver of the soil.  It is full of beneficial microbial life.  

While compost benefits all soils, it is still important to learn about your plants and the type of soil they prefer.  Plants, as people, have individual preferences.  

Many of our native perennial flowers like Black-eyed Susan, Rudbeckia fulgida, do best in less-rich soil.  If given too much compost or fertilizer, they may grow too tall and then need staking.  

Some, like Beebalm, Monarda didyma, will become overly aggressive growers in rich soil.  These plants are happiest with a half-inch top dressing of compost per year.  Shrubs do well with a half-inch to an inch of compost as a top dressing once a year.  

Talk to different gardeners and each one seems to have a different recipe for building soil fertility depending upon what they are doing at the moment.  In vegetable gardens, crop rotation is encouraged.  This practice reduces pest and disease buildup and avoids exhausting the soil as different crops remove different nutrients.  

Some people grow cover crops such as Crimson Clover in fall.  Then in spring, they till this green manure into the soil to supply extra nitrogen in a natural way.  Others prefer not to destroy the soil horizons by tilling the soil and garden with a no-till method.   

The moral is to find a system that works for you.  Learn to feed the soil and your plants will benefit. And remember—compost is your friend.

 © Mary Stauble 2010 all rights reserved