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Garden fabric, aka row cover or floating row cover, can be very handy to have on hand in your garden, as it can serve many purposes! 

Garden fabric can . . .

     *  slow evaporation from a plant and its surrounding soil

     *  act as a thermal barrier, protecting plants from the cold and the wind

     *  help to shade the plants, protecting them from overheating

     *  prevent insect damage, by keeping munching insects away from the plants

     *  stop birds and other critters from helping themselves to your harvest

     *  control pollination, in case you want to try very specific cross-pollination experiments

Available in different thicknesses, the heavier garden fabrics are better in the colder months (for heat retention), while the lighter fabrics are a much better choice when the weather gets hot. 

Also, remember that many vegetable and fruit crops require cross-pollination and, since the fabric will limit access to the plants’ flowers, pollination must be done by hand, or the fabric must be removed for an hour or two each day to allow pollinators to do their job.  Once pollination has taken place, the row cover may be left in place to protect the maturing crops.

In some cases, garden fabric should be cut into strips, and the strips wrapped around the stems of plants to protect them from boring-type insects.  E.g., most types of squash are susceptible to attack by the squash vine borer (SVB).  As the name states, the SVB (in its large caterpillar form) bores its way into the main stem of squash plants, and then eats its way through the stem, usually until the plant wilts and dies.  This attack may be prevented with a garden fabric wrapping of the stem.  The best time to apply garden fabric in this manner is before a seedling is put in the ground.  Start wrapping the stem about an inch below ground level, and wrap it all the way to the top, avoiding the side branches as you go.  As the plant grows, more fabric may be added, and the fabric already in place may need to be loosened to avoid restricting growth of the stem.  In this way, the stem is protected from vine borers, but the entire plant does not have to be covered, thereby using much less fabric.

For more info on this very versatile tool, see:  www.gardeners.com/Row-Covers/5111,default,pg.html

A living organism that can be used to control pests and/or diseases is called a “biocontrol.”  The following web sites all sell (or have a list of sellers of) Heterorhabditis bacteriophora, a parasitic nematode (microscopic worm), that enters and destroys the larvae of the cucumber beetle.  It is effective against some other larvae, as well.

1.  http://greenmethods.com/site/shop/buy-bugs/3/
2.  http://www.fertilizeronline.com/nematodes.php
3.  http://www.bugladyconsulting.com/Suppliers%20of%20beneficial%20insects.htm

And for more info on insect parasitic (i.e., “beneficial”) nematodes:  http://www.oardc.ohio-state.edu/nematodes/

Buying beneficial nematodes can be a bit pricey, especially for a smaller-sized garden, so you may want to try buying them and sharing the expense with other gardening neighbors, (which is always a good idea, anyway, since this helps to eliminate the pest from your entire neighborhood, not just your yard !), or you may want to try a different, less expensive solution first, e.g., the Burpee cucumber beetle trap.  However, these nematodes will eliminate some other pests besides the cucumber beetle, while the traps (I believe) are very target insect-specific.

Note:  Nematodes and other treatments that control the Striped Cucumber Beetle are equally effective against the Spotted Cucumber Beetle.

Spotted Cucumber Beetle (adult)

 [See journal entry, below, for more info regarding the Cucumber Beetle.]

FYI, last week, while examining our potato crops, I found a 1/4-inch long, yellow and black striped beetle — the Striped Cucumber Beetle — on one of the leaves!  This chewing insect can devastate a crop if allowed to munch and reproduce unchecked.  Besides the obvious leaf damage that they do, (which compromises a plant’s ability to photosynthesize, i.e., create food), these insects can oftentimes be vectors of plant diseases such as bacterial wilt and cucumber mosaic virus.  The adults feed on squash family plants, beans, corn, peas, and blossoms of many garden plants, often killing the plants.  Larvae feed on roots of squash family plants only, killing or stunting the plants.  Adults overwinter in dense grass or under leaves, emerging in early-spring to early-summer.  Eggs are layed at the base of target plants, and hatch in 10 days.  Larvae burrow into the soil to feed on roots for 2-6 weeks, pupate in mid- to late-summer into 1/2-inch, white grubs with brown heads, then, in 2 weeks, emerge as adults to feed on blossoms and maturing fruit.  One to two generations per year. 

NOTE:  Besides the adult beetle’s description, the above information regarding the Striped Cucumber Beetle also applies to the Spotted Cucumber Beetle.  See above journal entry for photo of the Spotted Cucumber Beetle.

Striped Cucumber Beetle (adult)

For more info on the Cucumber Beetle, and to see a diagram of the Life Cycles of both the Striped and the Spotted Cucumber Beetles, click here.

To control:  Remove and destroy crop residues where adults overwinter.  Use floating row covers to protect seedlings and plants, and hand-pollinate (using cotton swabs) the squash family plants.  Pile salt marsh hay or straw deeply around plants to discourage beetle movement amongst plants.  Apply kaolin clay to uncovered plants, using special care to coat the undersides of leaves, too.  Reapply after rain.  Hand-pick or vacuum adults, and/or apply parasitic nematodes, (Heterorhabditis bacteriophora), weekly to soil to control the larvae.  If all else fails, pyrethrin (a plant-based insecticide), may be applied to beetles seen feeding on pollen in flowers.

Most plant fertilizers usually include the three main plant nutrients:  N (Nitrogen), P (Phosphorus), and K (Potassium). This journal entry is about the first nutrient, Nitrogen. Nitrogen is available in different forms, and these different forms may lead to different results, where your plants are concerned. Since the different forms of Nitrogen may have different effects upon your soil’s chemistry, your plants’ abilities to take-up various nutrients (not just Nitrogen!) may be adversely effected.

For more info on the different forms of Nitrogen, and how these different forms may react in your soil, see: www.greenhouse.cornell.edu/crops/factsheets/nitrogen_form.pdf