Tips on soil temperatues, deer ticks, blackflies, mosquitoes
Memorial Day weekend marks the unofficial start of the summer season in much of New York state. The summerlike temperatures actually arrived a week ago, as we experienced almost record highs on both Saturday and Sunday.
For those of you who live in the higher locations of the Catskill Mountains, don’t be fooled by the heatwave, because we are still at risk of cold nights that can cause warm weather crops to appear to be ill, or malnourished. Although the air temperature may be in the 80s during the day, the temperature that is most important to your garden plants is the soil temperature.
Vegetable crops such as tomatoes and peppers may develop purple and yellow leaves or leaf blotches with slow to no growth as a result of poor nutrient uptake. Resist the urge to fertilize or add supplemental micronutrients to “correct” the apparent deficiency. If you are gardening in native soil it is highly unlikely that micronutrient deficiencies are the issue. The problem will cure itself as soon as the soil warms up enough to allow the roots to absorb the nutrients the plants need. Tan or brown blotches on leaves of cucumbers or squash plants are usually caused by windburn and will also go away once the soil reaches the optimal temperature of 75 degrees.
Some crops like peas, cabbage, beets, onions, leeks, spinach, lettuce, and other salad greens can tolerate colder soil, but even Chinese cabbage, cauliflower, and broccoli often bolt when night temperatures are below 50 degrees. If you are raising your own transplants, bring them in at night until nights remain in the 60-degree range.
If you are craving some fresh beans, try growing garbanzo beans since they can tolerate cold soil, whereas regular green beans prefer 70 degrees or higher. Don’t plant sweet corn until the soil is 75 degrees. Eggplant, peppers, okra, and even potatoes will grow much better when the soil is over 75 degrees.
Deer ticks have been active for weeks now, but mosquitoes and blackflies are just starting to hatch in large numbers. Both of these blood-sucking pests need water to complete their life cycle and managing water is crucial to controlling them. Blackflies breed in fast-moving water and there is little you can do if you live near a mountain stream that is flowing right now. Mosquitoes breed in standing water and not in streams, ponds, or lakes that contain fish or amphibians of any sort.
To reduce mosquito populations, get rid of anything outside that can hold water such as broken toys, tin cans, containers, ceramic pots, and in particular, used tires, which have become the most important mosquito breeding sites in the country. Drill holes in the bottoms of recycling containers left outdoors. Clean clogged roof gutters every year, especially if leaves tend to plug the drains. Turn over plastic swimming/wading pools and wheelbarrows when not in use. Do not allow water to stagnate in birdbaths, ornamental pools, water gardens, and swimming pools or their covers. Ornamental pools can be aerated or stocked with fish, and swimming pools should be cleaned and chlorinated when not in use.
Empty accumulated water from boats and cargo trailers. Alter the landscape of your property to eliminate standing water. During warm weather, mosquitoes can breed in puddles that remain for even a few days. There are products sold that are supposed to rid your property of mosquitos. A reader told me about one that he plans to try called “Mosquito Barrier.” The active ingredient in the mosquito barrier is garlic. I have not seen any scientific research that says garlic repels mosquitoes, but I have not seen anything that says it does not. I hope the product does not leave property smelling like an Italian restaurant! Or, maybe that is an added benefit, if you happen to love garlic!
Mosquitoes are attracted to carbon dioxide and some other chemicals that humans exhale and there are machines that emit these chemicals by a combustion process. Most, but not all, species of mosquitoes are pretty weak flyers and usually don’t wander too far, from the water where they “hatch” on your property. Wellplaced fans are safe and very effective at keeping a small deck mosquito-free.
One product that I do endorse is called “Mosquito Dunks.” These are donut-shaped, cookiesized, wafers that are placed in places that hold water, such as rain barrels. The “dunks” release a bacteria that is toxic to mosquito larvae, but pretty harmless to other insects, mammals, fish and amphibians. They last as long as a month and provide excellent control. Please do not use any sort of electronic “bug zapper” as these devices kill 99% harmless, or beneficial, insects and very few mosquitoes.