Farmers in wet climates usually build a permanent structure to store hay out of the elements. But what if you live in a climate that gets only occasional precipitation? You're quite unlikely to invest in a building that provides so little value. And this is exactly why farmers in relatively arid climates that should consider purchasing high quality tarps for hay protection. But exactly what properties should you look for in your hay tarps?
Why do I need to protect my hay from rain anyway?
The two biggest causes for lost hay are germination and mold. Both are caused in part by moisture. While you should also protect your hay from groundwater, the most common source of moisture is precipitation. For this reason, you should purchase a waterproof tarp. But a properly constructed hay tarp can also protect hay from the other major factor in germination.
So what else can a tarp protect hay from?
In addition to moisture, germination requires sunlight. High quality hay tarps are completely opaque, fully preventing light transmission. Poor quality hay tarps--as well as tarps that are not intended for this purpose--usually have some degree of translucency, allowing light to pass through. If the hay has both moisture and light, germination may occur, which makes the hay unusable as livestock feed.
What other features should I look for?
Most tarps have something installed to allow someone to easily secure it in place, usually either grommets or D-rings. Spacing between these attachments is important to consider. The closer they are spaced, the more points you can secure the tarp with. Additionally, there are other attachment styles that can occasionally be found on hay tarps, such as web loops. Web loops in particular can be rather convenient. You can simply slide a pipe or 2x4 into the loops, holding the tarp in place with their weight.
Cost vs Durability
As with any product, you must weight the cost of a hay tarp against its longevity and durability. A low cost hay tarp may not last very long, which would lead to replacing it more often and possibly losing the waterproof quality of the tarp just when you need it the most. It's generally recommended to opt for a higher quality hay tarp. The higher cost will be worth it because it will need replacing less frequently and you're far less likely to find yourself with a disintegrating tarp when the rain comes. In the end, it's still less costly to buy high quality hay tarps than to invest in the construction of a permanent structure.