Archive for October, 2012

Gardening: Fall’s symphony of colors a beautiful show

We have begun one of the greatest natural shows on earth and it happens every fall.  It is never the same from year to year but it happens very near the same time every year when the days get shorter and the nights get longer and cooler.  The big show is the symphony of fall color we get to enjoy as our deciduous trees and shrubs prepare to shed or drop their leaves for winter.  I’ve often wondered if autumn was named fall because of the falling leaves?  Some trees have already started changing colors after our early flirtation with the 32 degree freeze mark a couple of weeks ago. Many other trees are still a vibrant green and even producing new growth but all deciduous trees have started or will soon start the process of sugar storage, shutting down their seasonal food production and shedding their leaves before they freeze as part of the annual ritual of winter survival.

There are 3 main pigments that star in this annual fall color show.  They are chlorophyll, which provides the green color we see in leaves most of the year and is the workhorse of photosynthesis that uses sunlight to make sugars which are the food that fuels our plants.  Carotenoids produce the yellow, orange and some tones of brown.  They are at work in the leaf cells but are “masked” or covered up by the green chlorophyll most of the growing season.  Occasionally the carotenoids show through in bananas, daffodils, corn, carrots and others.  Anthocyanins produce the reds, oranges and blue or purple colors in red apples, grapes, cherries, strawberries, blueberries and cranberries besides the bright fall leaf colors that take our breath away.  The anthocyanins are water soluble and we get the best fall colors when we have warm days and cool but not freezing nights when the leaf is still making sugars in the fall but not removing them all from the leaf.  These excess plant sugars give us the bright colors of fall as the chlorophyll production shuts down.  Chlorophyll production slows down and then stops at slightly different times in different tree or shrub species based on day length and temperatures.  As the green chlorophyll stops production and gets used up or destroyed we can now see the yellow carotenoids that have been in the leaf all the time and the red, orange and purple tinted anthocyanins  created by the autumn production of excess sugars.  Some trees, like poplars, only show the yellow.  Other trees show the yellow carotenoids and then the red or orange anthocyanin.  Others like Bradford Pears and many maples seem to go right from green to tinges of red or purple.

Day length and cool weather are the most important triggers for fall color and are pretty much the same year after year but we get big variations in the other factors of light intensity, soil moisture and temperature that affect our deciduous trees and shrubs differently from year to year and assures that the fall color extravaganza is a new and different show each year. Fall is also a great time to plant new trees and shrubs to create shade for future summers and dazzling fall colors in future years

CHRISTOPHER COLUMBUS EXCHANGED PLANT MATERIALS AROUND THE WORLD

Happy Columbus Day! As we celebrate Christopher Columbus and the discovery of America we have entered the heart of the fall gardening season.  This continent has always been blessed with an amazing diversity of plant materials from long before Columbus.  Columbus and the explorers and settlers that followed began the great “swap shop” of plant material and genetics as they took newly discovered American trees, berries, flowers and vegetables to Europe and brought new seeds and plants from Europe, Asia and Africa to the Americas.  That exchange from around the world continues even today as we try to cultivate the best from everywhere while cherishing and saving our native plants.  Most Oklahoma gardens are a combination or melting pot of native and introduced plant material.

Most all of the state was blessed with really nice soaking rains over the last 2 weeks and it is amazing how quickly our lawns and most plant material have greened back up after those refreshing rains combined with the cooler temperatures of fall.  We have about 4 to 5 weeks of crisp fall growing season to enjoy our annual gardens before the first freeze but there are many hardier annuals, perennials and cool season fall crops that will survive the early light frosts and keep performing until we get a really hard freeze below 25 degrees, 20 degrees or even 15 degrees depending on the type of plant and the microclimate where you have them planted.

The hardy mums or fall Chrysanthemums are now in full color and most will stay really showy until the first freeze.  They do great in containers or the ground but are heavy drinkers and will need regular watering when we have warmer drying days.  The ornamental kale and cabbage will stay pretty well into winter and are now widely available at local nurseries.  Pansies provide a perky uplift of charming flowers in sunny areas throughout the whole winter, blooming even through snows and most other winter challenges with just a little watering attention if we get dry during the winter.  Few things cheer me up as much as the bright colorful pansy faces in their full palette of yellow, orange, red, bronze, blue and purple flowers on cold, dark winter days.  To experience that joy yourself buy a flat or two of pansies to plant along your sidewalks or in large decorative pots on your porch or patio.  If you want a green winter lawn you need to overseed with tall fescue in the next couple of weeks and then water well.  Don’t forget now is the prime time to buy and plant all your spring flowering  bulbs like tulips, hyacinths, crocus and daffodils to assure a great round of flowers to kick-off next spring.

Fall is one of the best times to spend time in the garden so I hope you will make time to plant flowers, bulbs and trees but also just to walk, sit and meditate in the great outdoors of your yard.