10 June, 2010

Japanese Beetles Ready to Attack

Sooner or later we knew it would happen. Summer is just a week away even though we have had glimpses of hot humid weather now and then since April. Plants got ahead of themselves by several weeks at the onset of April only to be put back in check by a hard dose of normal reality, a hard freeze. By the time May came to town the whole weather scenario seemed to even itself out. The early blooming in April did not extend into May. Finally what was supposed to bloom in May bloomed in May and the final frost date of May 15th came and went without cause. And now it is already the second week of June. I always thought time went faster as one got older for the simple reason that each passing year represents a smaller percentage of your total life. For a five year old one years is a whopping twenty percent of their existence. But at twenty years of age that percentage drops to five. For us midlife crisis sufferers? A year dwindles to a measly two percent of our existence when you hit fifty! But just ask a high school kid and they too are seeing time fly by.
 
Back to gardening, my intended topic. Mid June also announces the arrival of bug season. We see the crowds drift back to the bug juice section of our stores this month. May is spent in the plant departments. June is remedy month.  Time to fix problems hitting the plants placed in the ground in April and May. The problems run the gamut of mildews, weeds, slugs, bugs and other thugs that can ravage a garden if left unchecked. Though the trend is towards organic and natural controls these products are still pesticides and deserve respect from the applicator. We in the garden industry cannot say it enough, "Always read and follow label instructions". I have been in the garden business for thirty years and I always read the application rates on the label for the simple reason that one label looks like every other after.
 
Of all the pests we will see this month the one with the most voracious appetite is the Japanese beetle. About the size of a dime and the color of a shiny copper penny, these beetles launch their attack on almost everything in the garden in mid June. The calling card of a Japanese beetle is a leaf surface decimated leaving only the skeletal appearance of its' veins behind. Preferring to munch in the sun beetles devour cannas, basil, birch trees, egg plant, potatoes and dozens of other ornamental species. Not to eat and run beetles lay eggs in our lawns by mid July that when hatched become those little milky white grubs that destroy lawn roots as fast as their parents ate your snapdragon leaves!
 
Controls for Japanese beetles that work well and quickly are few with organic controls being even fewer. Sevin, the maligned but effective, insecticide is still my first choice when beetles strike. Sevin kills beetles on contact and leaves behind a decent amount of residual control beetles that are sure to come around later.  I have no problem hitting my tomato and pepper crop with Sevin for beetles. These are long term crops that are nowhere near ready for harvest in June. Basil, other herbs and leaf crops such as spinach and chard are a different matter.  Sevin is not a good choice for these crops because they are ready to eat just as the beetles attack. The best mode of attack on these tender leaf crops is a combination of hand picking the bugs off and botanical sprays like pyrethrins and other plant made oils. Botanical controls like pyrethrins can be applied up to one day before harvest.
 
One way to prevent Japanese beetles from attacking in the first place is to apply Milky Spore to your lawn areas. Milky spore is Bacillus thuringensis, a natural pesticide, and stops grubs from maturing into adult beetles. When the grubs ingest Bt they stop eating and die within a few hours.
Milky Spore is best applied in a powder form. It takes two to three years to spread throughout the lawn but will remain effective for 15-20 years. Although the initial outlay is more than the cost of using Merit the long term cost is much lower.