Friday, April 15, 2011

A Shady Deal

As everyone knows, the earth’s elliptical trip around the sun causes the days to become longer and the sun to feel hotter in the Spring and Summer. The inverse is true during the Fall and Winter. While we welcome this annual progression, particularly in the Spring, it can wreak havoc on the greenhouses and hoophouses if we are not careful.

The plastic covering of the hoophouses provides a wonderful break from the wind. It also allows heat to collect. Heat which can be helpful in promoting growth in the cooler seasons. But, with the greater amounts of sunlight, heat can kill. There has to be a way to control the airflow and maintain a somewhat constant temperature.

Enter SHADECLOTH! The black knit fabric offers different percentages of shade when applied over the plastic skin. This can make a difference in temperature of up to twenty degrees on a hot summer day. Coupled with the ability to roll up the plastic sides, the temperature and airflow can be regulated.

One might wonder why this is important. Without the shade, or the lowered temperatures, the hoophouses would be relegated to growing only hot weather crops. If we shade the houses, we can grow lettuce and other tender greens all summer. Last summer we added irrigation to the hoophouses, and the quality of the produce greatly improved. Overhead watering can lead to disease and plant loss, especially when in combination with high temperatures.

The shape of the house also affects the heat retention. The semi-round shape of hoophouse #1 combined with the lower roof height, makes it a warmer environment year-round. So, once the sun reached a certain point, it was time to apply the shadecloth.

As with most everything around here, we go low-tech. We even put to use the old jolly ball that was once a horse toy for A’s pony. The pony may be gone, but that toy is really useful!

Ropes are attached to the cloth; the cloth is pulled over the house, and ta-dah! the house is instantly cooler!

With #1 shaded, the lettuce should flourish without the worry of bitterness caused by high temperatures. Now, we need another "still" day to cover #2 and the two greenhouses.

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