Thursday, February 23, 2017

Signs of Spring & How to Warm Your Soil

A beautiful apple blossom with large king bloom in the middle.  Oh how I am looking forward to spring.

Outside the north wind is blowing and I trudge through ice and snow bundled up as I go feed the goats, chickens, and ducks.  But the day before I was 70 miles south visiting family and it was a beautiful 70 degrees.  I meet fellow gardeners in the garden section of the local nursery with dirt already under their fingernails.  I admired the transplants of broccoli, cauliflower, lettuce and kale already in the store and sighed.  Spring has sprung there but sadly not in New Harmony.

Peach trees in bloom.

Deciding when to plant is a perhaps one of the harder decisions especially to a new gardener or if you have moved to a new location.  

Determining when spring has sprung has more to do with observing natural events than a particular date on a calendar.  The official declaration of spring occurs with the vernal equinox which is around March 21 or 22nd.  This date has no bearing on the appearance of spring for the gardener.  In some areas of the north "spring" won't actually make its appearance until May or June and in the south is may already be too late to plant some crops.  

Pear blossoms

So what does the Spring equinox tell us?  On this day the suns rays fall straight down on the equator.  Around the globe the length of daylight and night are equal.  From then on the hours of daylight will increase.  For many that is reason enough to rejoice.  This day does influence the behavior of animals.  Increasing daylight triggers courtship, migration, and other behaviors.

So how do you determine when spring has arrived?  The temperature of the air is less important to plants than the temperature of the soil.  The only dependable thing about spring is that is is fickle.  It toys with your emotions appearing then quickly retreating.  In our part of the country they say, "If you don't like the weather wait 5 minutes and it will change."  To understand planting schedules it is more important to look at nature herself and the observe when certain indicators begin the "spring" forth.

Early spring bulbs

Some signs of spring:

  • Buds swell
  • Sap begins to flow
  • Appearance of certain insects
  • Appearance of certain birds
  • Spring bulbs emerging
  • Emergence of weeds
  • And the smell of the soil warming.

Emerging tulips are a welcome sign of spring.

Warming Soil

I want to focus the last one-  warming soil. Why is soil temperature important?

As the temperature of the air rises and sunlight increases it begins to warm the soil.  This warming of the soil awakens the living organisms in your soil.  Microorganisms like bacteria, fungi, and protozoa come alive and restart the process of decomposing organic matter. This process of decay is what will make your soil rich in nutrients and gives it the earthy smell that gardeners love.  Earth worms migrate up  when the soil is frost free eating there way through soil, aerating as they tunnel, and depositing castings which enrich the soil.  During winter months or drought the earthworm burrows deep in the soil, encases itself in slime, and "hibernates" until the soil warms and there is moisture.

What The Gardener Should Do

This is why I feel it is important to add organic matter in the form of compost and aged manures in the garden in the fall.  You want organic matter available for these organisms in early spring.  It is the food source of soil organisms and combined with the warming sun will awaken the soil food web essential to organic gardening.  I add additional compost again when planting along with and organic dry fertilizer.

The minimum temperature that seeds of cool season crops can germinate is 40 degrees.

It is possible to assist nature in warming your soil.

Build Your Soil

 A sandy loam soil with organic matter will warm more quickly than a heavy clay soil.  

Raised Beds

Soil in a raised bed warms more quickly than bare ground.

Plastic Mulches

Plastic mulches can be used to warm the soil.  For northern gardeners they can be used to warm the soil to get an earlier start on melons, tomatoes, and peppers.  Stretch the plastic mulch tightly across the bed and secure the edges.  I recommend using a plastic mulch specifically for gardening.  Black or clear plastic do NOT allow for the movement of air and water and are used more for solarizing the soil or killing weed seeds.  

Hoop Houses or Low Tunnels

This is what I use in early spring to get a head start.  Low tunnels increase air temperature during the day and retain heat at night.  An additional row cover can be placed over plants under the low tunnel.  They are inexpensive to build and easy to remove and relocate.

Early spring crops grown under a low tunnel.

You can see row covers in the background and a low tunnel.  Both allow you to plant earlier.

Cold Frames

Cold Frames are a bottomless box of glass or plastic placed over an existing bed.  They are more expensive and you must monitor the inside temperature more closely because they offer more protection from frost and heat up more readily than a row cover.

Hot Caps

Hot caps cover individual plants creating a mini greenhouse.  They are an options if you have only a few plants to protect which is rarely the case in my garden.

Word of Caution

For those of you that are like me and get spring fever in February whenever the sun shines and snow melts and seed packets arrive in the mail, be gentle with spring soils.

Seed packets will say to plant as soon as soil can be worked.  So what does that mean?

Because spring soil has a lot of moisture in it, the soil compacts easily.  Every time you step on your garden soil your weight squeezes out the air and when the moisture evaporates it drys into a hard clod.  Even hoeing or turning a wet soil can compact the soil particles together.  While weed seeds don't seem to mind hard compacted soil, garden seeds are more particular.

So when is it OK to "work the soil?"  Grab a handful of dirt from your garden beds, squeeze it, then open up your hand.  If the ball of soil crumbles on its own or crumbles when you poke it then go ahead and work compost and dry organic fertilizer into the soil.  If you have sticky mud ball then wait for the soil to dry out. 

When working the soil in open ground and if you cannot avoid walking on your soil, lay boards out on the garden soil to distribute your weight.  It is a better option to have specific paths to walk on and avoid walking in your planting areas at all.  

"When a spadeful of earth crumble, the plows may be started, but not while the spade comes out of the ground smeared."  John P. Morton & Co.  Western Farmers' Almanac 1884

1 comment:

  1. Thank you for the information! I'm still working on my gardening skills, so this is very helpful. And, beautiful pictures!