NEIGHBORHOOD GARDEN FOR FEBRUARY 25, 2012

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SOIL OR DIRT?

BY GLADYS JEURINK

 

So what is it?  Soil or dirt? Soil comes from rock, freezing, rain, and roots, wind, and sun. All have helped break it down and the process goes on as plants add material, and the fungous, worms, bacteria and other organisms do their share. Pick up a handful of your soil. Only about half of it is actually solid material.  The rest is living and dead organisms, and plant material plus air spaces that are so important for your roots.  This is why all garden articles say to stay off of your beds.  Isn’t this some of the theory of “no-till” farming? Those roots as they decay leave trails for air and water to go down.

For outside in the vegetable or flower bed, the ideal soil is loam. A formula says it contains 2 parts each of sand and silt, and one part clay, plus as much compost as possible. Silt is described as fine mineral particles, sand as large particles while clay is extremely fine. Sand with its big pieces has many large pores so it has good drainage but that drainage allows water and fertilizer to go down below the root zone.  On the other hand clay is so fine it leaves little pore space and it difficult for water to enter so it runs off the top.  Each little particle will hang on to water or fertilizer once it gets to it so it is very fertile soil.  Clay swells when wet and shrinks when dry (see those cracks).

Outside we add compost to both.  I have heard it said you can not have too much compost! It supplies nutrients from the decayed plants, it slurps up water like a sponge and because the particles are large, they create the air spaces that plant roots need. It encourages such creatures as worms that eat it, produce castings and dig more pathways for water. If you have enough space it is good to dig a ditch, fill it with compost or weeds (not seeds), rhubarb leaves, etc. and when full use the next ditch to cover it up.  This will make your soil deeper in food.  If I dig up any sod, I place it upside down in the ditch.  This is called “trench composting”.

          So soil is not dirt! Dirt is what you wash off your clothes or the puppy brings in on his feet.  Soil is a complex mixture full of living things such as fungous, worms, insects, and bacteria and can change for better or worse depending upon how you treat it! Crickets love compost piles and so do roly poly’s.

          If you are curious about your soil use a jar with straight sides, add a cup or so your soil, and shake it up.  Don’t just take a little off the top but take a slice of dirt 4 or 5 inches down so you have a good sample. Add at least 2 times as much water as soil and shake well to thoroughly mix.Then place the jar on an even surface and it settle.  In 24 hours the sandy part will be a layer on the bottom, the silt will be in the middle, with the clay as the top layer. This will give you the proportions of each you have.

          Watering is affected by your soil type. We are told to water long and deep and less often.  Clay soils tiny particles are slow to pick up water.  One author says as much as 50% of water runs off clay.  The ideal is to water till you see a puddle, turn off the water and let it sink into the soil, then repeat.  Sand and loam soils have large pores and the water will disappear but these soils dry out faster so it is important to know your soil. 

          Compost is the answer many times.  It creates pore space for air and water, it absorbs a good deal of water, it provides food for the plants, slows down drainage in sandy soils, and aids clay in holding water. Once you know what works best for you there are timers to put on your system.

What about your container plants? Clay pots take up water and lose it through the sides so you need to water more often but they are heavier so they don’t upset as easily. Plastic pots are lighter in weight and don’t breathe so hold water longer and cost less but you may not like the way they look. If you leave them outside in winter they are much less likely to break than clay as the water in the clay pores freeze and expand and they crack and peal. I have mainly the ceramic pots so I like to turn them upside down in the late fall. The plant have been removed and the soil is dry by then, so it falls down loosely so any water that freezes cannot put pressure on the sides.

          An important part of our soil is the pH.  Here in Lincoln and for most of Southeast and South Central Nebraska, the pH is usually about seven (neutral) or above (alkaline).  In parts of the United States it can be acidic (below 7). Most of the soil in the Northeast United States and along the East Coast is acidic (6 or below) so watch out for TV programs from that area or books and articles that talk about growing plants as they may add lime to increase the pH which is not recommended for us. Only certain plants can survive at either extreme of pH. To grow Blueberries or Rhodendrons and some Azaleas, we need to add acid. My favorite is pelletized sulphur that I put on in the fall in order for it to have any affect by the next spring. Powdered Sulphur does just as well but blows around if not dug in.  I have never liked Aluminum Sulphate as Aluminum can tie up the Phosphorous in the soil.  Vinegar can have a pH or 4 and oven cleaner 10.

          Before planting acid loving plants, especially Blueberries, it is recommended to dig the hole and then add the sulphur and also Canadian Sphagnum Peat Moss to the soil. These two items will lower the pH to give the plants a good start.

Copyright 2012