Thursday, November 13, 2014

Looking at Leaves as Fall Arrives with a Blast of Arctic Air



We started to enjoy autumn yesterday. I rescued roses from the garden just before the killer frost settled down on the fragile flowers. Green tree leaves burst into spectacular colors. Who needs Door County, Wisconsin for Normal Rockwell photos?

Our helper came over to work on the leaves. We mulch-mow the front yard and Mrs. Wright's. I reasoned last year that leaving her leaves blowing around was counter-productive. Our Lowe's mower turns the leaves into tiny scraps that blend with any grass clippings for feeding the soil. I rake up extra piles for the crepe myrtle bush. We will win the best bloom competition next year. Three things will do this for the crepe myrtle, despised by many for being hardy and prolific:

  • Feeding with mulch all winter.
  • Pruning in the spring.
  • Earthworms sprinkled on the mulch to wiggle into the soil below.


One oddball publication assumed all worms die during the winter. I have not done a survey. I assume most of them in unprotected ground will succumb. However, rotting material above generates heat and keeps the soil warmer, blocking the drying, killing winds. A heavy snow cover is much kinder to plants and soil creatures than a dry cold winter without snow. Finally, a weather holocaust would still leave the egg casings ready to hatch wormlings in the spring. A compost pile will distribute worms and casings when used. Our compost will be shared with the corn patch.

Our helper looked helplessly at the leaves in the backyard. They were piled up against the fence, on top of the wood and newsprint mulch. "How can we rake those?"

I remained composed in the crisis. "We will use them in the spring." My plan is to plant roses parallel with the fence between us and  Mr. Gardener. We will dig holes in the lawn, plant the roses, and mulch afterwards. We want them close enough for Mrs. Gardener to cut some for herself. We can get the leaves away from the fence, incorporate them in the mulch, and cover with shredded cyprus.

Some leaves will go in the compost and others will be used to create the wild area in the back. One must plan carefully to go wild. That will include Butterfly bushes, sunflowers, and various hardy and prolific herbs/weeds.

I think of people who rake, rake, rake, and bag, bag, bag, then set the leaves out in color coded plastic sacks so the professional refuse people can collect them. These rakers and baggers are the first ones to buy fertilizer at the big box stores when spring arrives. Soil fertility is so-o-o-o-o-o important to them.

Apical meristematic tissue is located just below the tips of shoots and just above the root caps. These cells can mature to become any type of cell in the entire plant and are responsible for increasing plant height and length. 

Lateral meristem cells add diameter to plants.   

Ground tissue provides most of the bulk of a plant as well as its support. These cells also serve as sites for photosynthesis, food storage, protection, and regeneration after injury.   

Vascular tissue is made up of xylem and phloem vessels that transport water and nutrients.   

The xylem carries water and dissolved nutrients upward from the roots. Transpiration, cohesion, and adhesion allow water to move through the xylem without the plant expending any energy.   

Phloem vessels move sap (water and materials produced by the plant) both upward to the leaves and downward to the roots.

Dermal tissue forms the skin of the plant, which keeps in water and helps to protect the plant from external injury.   

Stomata are pores in the epidermis that open to allow carbon dioxide to diffuse into the leaves and water vapor and oxygen out.   The key function of leaves is to provide the platform for photosynthesis. 

Chloroplasts reside in cells between the two layers of epidermal cells that cover each leaf.  

Root hairs are extremely important to the uptake of nutrients. Each is a single epidermal cell that can grow to an amazing length.   

Roots take in water and nutrient ions with the aid of microbes that live in the soil.   

Mucilage is the mixture of sloughed off root tip cells, exudates from root tips, and microbial populations and by-products. It acts as a lubricant for roots growing into soil and influences the uptake of nutrients, particularly metal ions.

Jeff; Lowenfels, (2013-05-07). Teaming with Nutrients: The Organic Gardener’s Guide to Optimizing Plant Nutrition (Kindle Locations 1423-1445). Timber Press. Kindle Edition. 

Above is just a summary of a section dealing with plant anatomy and how various parts contribute to the soil food web.

Root cap cells help build the mucilage that lubricates the root and the soil, making it easier to penetrate and increasing the contact between the soil and the root. Eventually, the outer cells of root tips are sloughed off and replaced by new root cells produced in the meristematic tissue. These sloughed off cells supplement the plant’s exudates (sugars and amino acids, mostly) that attract microbes necessary for nutrient absorption to the rhizosphere. The mixture of microbes living in and digesting this sloughed-off cellular material generates wastes that contain essential plant nutrients, particularly nitrogen. 

Mucilage has a great influence on the uptake of nutrients, particularly metal nutrients, into plants. Phosphorus, zinc, iron, and magnesium all diffuse into the mucilage gel and from the gel into the roots. This gel is particularly apt at oozing into soil particle crevices and pores, thus increasing contact with the surfaces where these metals are located. Mucilage contains acids that dissolve phosphorus, which can then diffuse through it to the root. In addition, chemical reactions that occur in the mucilage and the gel’s pH result in the uptake of metals. Plant exudates become part of the mixture, produced, at least in part, in direct response to the need for some nutrient or a need to turn off a nutrient supply, which requires a change in the mixture of microbes. In any case, the presence of mucilage contributes to the rhizosphere chemical factory. Some plants take up various metals in greater quantities than others due to the makeup of the root mucilage mixture.

Jeff; Lowenfels, (2013-05-07). Teaming with Nutrients: The Organic Gardener’s Guide to Optimizing Plant Nutrition (Kindle Locations 1365-1377). Timber Press. Kindle Edition.