Last winter hay was scarce and expensive. It doesn’t look like this winter will be much better; weather conditions this summer made it difficult to cut and bale hay, resulting in a shortage in many parts of the country. Here in New England, hay is about $350 per ton, so when you have two tons delivered, you want to make sure that it’s stored properly.

It doesn’t sound like rocket science, but there are tricks to stacking hay to keep the bales from breaking, to avoid heat build up, and to prevent the hay from becoming moldy or infested with insects.

To begin with, it’s important to buy hay that has been baled at the proper moisture level. When it’s first cut, the moisture level in hay is about 80%; to minimize the risk of fire, the moisture content should be less than 15% before it is baled. A few years ago, I was offered some hay inexpensively from someone in the town where I lived, baled in his fields. The sample bales I received were lovely, but I discovered when he’d delivered 50-odd, that the hay has been baled while too damp. The result was bales that first got too hot, then turned moldy. Not a bargain at all.

Ideally, hay should have a moisture level of about 12-15% when it’s baled. Hay that has too much moisture gets hot because it creates an environment where bacteria and mold fungii are able to survive and create heat by consuming the hay. In worse case scenarios, the heat generated can cause the hay to spontaneously combust. Dry hay generally kills the microbes or causes them to go dormant. However, if the hay is too dry then the leaves will fall off.

Here are some tips to consider:

• Storing hay away from your barn — and your horses — is the safest way to go, but not always possible. Where I keep my horses, for instance, the loft is the only place to keep it! If hay has been cured properly before baling, stacking it tightly is not a problem and it will hold its leaf shape better.
• Stack your hay inside if possible; if you leave it outside covered with a tarp, moisture can seep into the hay and cause problems with mold. If you must stack it outside, using a pyramid structure under the tarp will encourage moisture to run off.
• Stack hay on wooden pallets to allow for airflow under the bales (you can get them for free from many businesses). Stacking directly on concrete or dirt will allow moisture to wick up from the ground and penetrate the bales. I’ve also read about someone who stacks hay on top of bagged shavings (wrapped in paper) as they absorb any moisture from the floor.
• Position bales with the cut side facing up (strings on the side) and criss cross each layer. This protects the baling twine from being nibbled by rodents and maximizes stability. It’s terribly frustrating when bales break and you have to move loose hay.
• Store hay in an area with vents or windows to encourage air circulation.
• Do not store hay near anything flammable or any source of heat.
• Do not stack hay higher than you can safely move it or stack it in a manner which could greatly accelerate the burning of a fire.
• Do not allow anyone to smoke around your hay or in your hay storage area.
• Don’t stack new hay in with older bales. Pull the old bales to the front and feed those first.