Monday, March 25, 2013

The ABC's of Composting

 The popular practice of composting is defined as the process by which organic materials biologically decompose under controlled conditions. Perhaps the most notable point about composting is not to make it more complicated than it is.  By merely throwing a pile of twigs and leaves in the back corner of the garden, you are composting; of course, it may take a year or so to breakdown.  But by following a few simple, but vital rules you can speed up the process and produce good compost in about a month or so. The following some are key principles:

 a. Proper moisture and air (oxygen) content - Compost works best if the moisture content of the materials is about 50%.  That’s not easy to measure, but it has been estimated to be about the moisture content of a wrung-out sponge.  If the material is too dry, decomposition will stop; if too wet, oxygen is excluded and decomposition will slow and odors will be produced.

b. Proper carbon/nitrogen ratio - For effective composting, the raw materials must have a proper carbon/nitrogen ratio – set at about 30:1.  Since this too cannot be easily measured, experience has shown that mixing equal volumes of green plant material with equal volumes of brown plant material will give this ratio. The greens are fresh moist materials like grass clippings, weeds, manures and kitchen scraps. The browns are dry materials such as twigs, wood chips, straw, saw dust and paper.  If a pile of twigs are thrown to the side, they will eventually decompose. When leaves (greens) are combined with the twigs (browns) in the proper ratios, decomposition will occur more rapidly.    
Mixing grass clippings with twigs or chips is not only good for obtaining the proper ratio but also helps to maintain a good oxygen level.  Grass clippings or shredded papers alone tend to mat and exclude oxygen.  Adding twigs helps to open the pile allowing a better movement of air.   

c. Proper size of material - Soft, succulent plant tissue doesn’t need to be chopped into small pieces because it will decompose rapidly. Woody materials, however, will decompose better if pieces are ½ to 1 ½ inches in size: the smaller the pieces the quicker the decomposition.

d. Proper pile size - The size of the compost pile is important.  The minimal size is 3 cubic feet (3x3x3). Maximum size would be around 5x5 and as long as desired.

e. Proper turning- Turning the pile is not required but will certainly speed up the process if turned every day to every ten days. Turning helps ensure proper air circulation, moisture and heat distribution. 

What should NOT be put into the compost pile? Meat, fat, manure from meat-eating animals as well as human waste. Manure from herbivores such as goats, cows, horses, rabbits and even elephants can be used.  It is not good to throw diseased plants into the compost pile, because the pile may not reach the temperatures that are required to kill plant diseases and weed seeds. 
Finally, here’s how to know when the composting is finished: when the majority of the pile has become dark, loose, crumbly and sweet smelling.  Also, the original materials will not be recognizable with the exception of a few pieces of tough woody material. 

Composting is a good way to reuse our natural resources, recycle nutrients and add good organic matter back into the soil.  

Monday, March 18, 2013

Controlling Bamboo

Bamboo is one of the most difficult plants to control. In fact, one of the best methods of control is prevention: do your homework before planting, learn about the different types and varieties and encourage your neighbors to do the same.

Homeowners with unwanted bamboo must be patient, as it requires an intensive control program which may last several years. Start with physically removing as much of the rhizome and root mass as possible, either by hand or with power equipment for larger areas.  If total removal is not possible, cut down the bamboo, wait for new growth to sprout, and then cut it down again, and again. Continue until no more shoots come up. Using this procedure, you are eventually exhausting the energy stored in the underground rhizomes. By constantly removing the foliage, you deny the plant the ability to photosynthesize and produce new energy so the rhizomes can no longer send up new shoots. If feasible, regular mowing will also work in this same manner, and over time the mowing will deplete the plant of energy.  Because bamboo is a grass, it can tolerate occasional mowing but does not tolerate frequent mowing. As much as two to three years of regular mowing may be needed in order to see results.

When controlling bamboo, it is often necessary to use herbicides.  Roundup (glyphosate) is one option for homeowners. It does not have residual soil activity and will kill only those plants that receive direct contact. First the bamboo must be cut, and then allowed to regrow until the new leaves expand.  Apply the herbicide at this point. Since Roundup does not translocate well to the rhizomes (i.e. transported from the leaves back down into the rhizome), the bamboo will likely re-sprout. Reapply Roundup whenever new growth is present.  It could easily take two years or more of this regime to attain control. Persistence is key.  

Another herbicide, Arsenal (imazapyr) is actually more effective than Roundup against bamboo.  The drawback is that unlike Roundup, imazapyr is soil active and will potentially kill other trees and shrubs and all grasses if their roots extend into the vicinity of the application. Therefore, if the bamboo is growing near any desirable plant species, Arsenal should not be used. As with all pesticides, the entire label ought to be read to make sure the material is being used in a safe manner, according to all label instructions.

If the bamboo in your yard has come from your neighbor’s yard, separate your ‘grove’ of bamboo from his by cutting the connecting rhizomes. They are usually quite shallow. If you don’t, your neighbor’s bamboo will continue to be a food source, providing energy to your bamboo and your efforts of cutting, mowing or spraying will be in vain. In addition, if not separated, any herbicide you apply has the potential of affecting your neighbor’s bamboo. To prevent a running bamboo from spreading, a barrier placed two to three feet deep in the soil can be effective. Barriers should be made of concrete, metal, or high density plastic. 

 In defense of this plant, bamboo can be a beautiful addition to a landscape. There are varieties of bamboo that do not spread out of control. Some varieties are even used for building, for furniture and for food.

Monday, March 4, 2013

Seedless Watermelon

 How do plant breeders obtain seed for a seedless watermelon?

 This is accomplished by making several different types of crosses between watermelon plants. Without going into a long genetic lesson, it first begins by doubling the number of chromosomes  (threadlike bodies in cells that contain  genetic information) in a normal watermelon plant.  This is done by chemical treatment. This new plant is referred to as a tetraploid because it now contains four sets of chromosomes instead of the normal two.  When the tetraploid plant is bred back, or pollinated, by a diploid plant, the resulting seed produces a plant that is basically a "mule" of the plant kingdom – one that produces seedless watermelons. The flesh of this melon is usually firmer than seeded varieties, because the usual softening of the fruit around the seeds does not occur.