Hay Molded/Mildewed in Storage

[Bicoastal]

When my hay was tested at the beginning at August, the moisture percent was 7.9%. I just saw that the hay stored in the lean-to (open on both sides, roof overhead), has mildew growing on the outside. Some hay left over in mangers also has mildew or mold growing on the outer surface.

The roof is not leaking. The hay never got wet directly from rain. The small square bales are up off of the ground. Hay put up in this space two years ago is still in good shape and usable. I’m in VA and we had a couple weeks of extreme rain from Hurricane Helene. Lots of humidity.

What do I do now? I can’t imagine the hay supplier will replace it. Can I salvage it? And how can I prevent this in the future?

[Texarkana]

I prevent it by not buying hay until later in the fall, because it almost always happens to me!

If it’s not too bad, you can probably get away with feeding it. Some people steam it to kill the mold. Maybe you can find a cow or goat person unbothered by it to buy it off you at a loss.

[Bicoastal]

@Texarkana

I prevent it by not buying hay until later in the fall, because it almost always happens to me!

It almost always happens?!? Nooooo!!! I start stressing in July if I don’t have my hay lined up. We were drought (you’re Eastern Shore, right? I’m central VA), so I was REALLY stressing. And I’ve never lost hay in storage before, even the bottom row. I can imagine the humidity is an even bigger problem on the shore.

We know lots and lots of people buy second or third cutting in the summer and store until winter. In humid areas, how are they successful?

[luvmyhackney]

Are you storing on concrete? Pallets? Good airflow in the storage area?

Can’t say I’ve had hay mildew even when I lived in eastern NC.

[Texarkana]

@Bicoastal

It almost always happens?!?

Yup.

It was a problem for me in middle TN and it’s a bigger problem for me now here on the eastern shore of MD.

Dry hay in a wood shed with ventilation on pallets still gets surface mold in the summer months.

I didn’t have this problem when I lived in PA, north eastern MD, or central VA. It would occasionally happen in TN but my gosh it’s almost guaranteed here.

[Scribbler]

I store in an upstairs wooden loft. If I don’t tarp well I get outside mildew on the bales in back. It’s not the inner dampness of the hay it’s the ambient humidity. If it’s just the first flake I toss that and continue feeding. Tarps are your friend for air humidity.

[SusanO]

Happens in Alabama too. Mine is stored on a flatbed trailer under the overhang of the barn so it does not get wet. 6 months is about it for me. After that the surface is getting musty. So I have to buy in the Spring and then again in the Fall after it has cooled off. This summer was pretty dry so the hay I bought in June is fine. But I don’t want to get my winter hay until that is gone because it is reaching the outer limits. I wish I could buy a year’s worth at one time because I got some reasonably priced lovely hay this Spring. When I run out I suppose all that will be available is either junk or $$$$.

I do find bundled hay or the big 3x3x8 bales last longer. I think because it is packed more tightly with less surface area. Now if I had a hay loft I would probably be in better shape, but I don’t. I don’t think you can get your hay supplier to take the hay back unless it came that way. That is not their problem if it gets musty in your storage. Another way to avoid this is to buy smaller quantities that you use up faster. But I know this subjects you to the situation where the good hay is all sold out.

[Bicoastal]

@luvmyhackney

Are you storing on concrete? Pallets? Good airflow in the storage area

Hay is stored in a wooden lean to with metal roof. There is a small loft storing old lumber a couple feet above the hay bales, which are up on pallets.

There is a roof and two side walls, with front and back open. Should be plenty of cross ventilation.

I’ll climb in this weekend and see how extensive the damage.

I buy my winter hay supply in summer. I do not feed hay year round.

[Demerara_Stables]

I never bought more than 3 weeks worth in Florida. It would mildew incredibly fast. I still only buy a month at a time here in CA. Don’t want to take the chance of it going bad. I’ve fed dusty hay but never fed if it smells mildewy - mine wouldn’t eat it either.

[StormyDay]

I’m also in VA. My freaking walls got mold. Tack that has never gotten mold grew mold. I think the mold got mold. I have never experienced that high of humidity up here. It was insane.

I think this year was just a really crazy year and unfortunately crap happens. The only real way to prevent it is to store your hay in a room with a dehumidifier; but who knows; we may not get another rain event like that ever. (Or at least I can hope) You might be able to feed the bales that are deeper in your stack. You may also be able to sell it to a cow farmer who won’t care as much about quality.

[Bicoastal]

@StormyDay I’m so sorry. I’m also relieved to hear from a Virginianian who experienced the same thing, so I can kick myself a little less. Maybe there was nothing I could have done. It was an extraordinary weather event.

A picture is worth a thousand words. Here’s a photo of my hay storage area: hay doesn’t touch the walls or roof, open to air on two sides for cross ventilation, off the ground.

[Simkie]

We have a shelter logic type “garage” we use for (not hay) storage. Putting a heavy duty tarp on the ground made SUCH a difference in the humidity level inside. Keeping ground moisture from evaporating and coming up keeps it from being a sauna.

Maybe something to try? You’d just want to make sure it was interior enough that there was no chance of rain hitting an end and water traveling across the top, under your hay. That definitely wouldn’t help!

[Texarkana]

Tarping would probably help a ton in your situation, including tarping the ground so moisture can’t wick up from the clay.

[SusanO]

Also cleaning up the floor and putting down a layer of big crushed rock. But a tarp would be easier and cheaper.

[ChocoMare]

I did self-care board on a organic hay farm for 13 years. Learned lots about storing hay

I’ll ditto the suggestion of a layer of crushed gravel, followed by a tarp and TWO layers of pallets if you can only do the wood ones. However, if you can find the super duper heavy duty ones (like a Soda bottler would use) instead of wood, you can do one layer down. That’s what we use in our hay barn. (No more rotting, mold generating wood or splintering.)

When stacking: First layer of hay bales down should be cut-side-up and then stack the rest log-cabin style, leaving a 1/2" gap in between. Max air flow. You still may get some outside flakes yellowing, etc. Normal - just toss and feed the inside.

[4horses]

Dehumidifier might help? This is the first year I’ve really noticed mold in my hay. But I usually feed it so quickly it’s gone before it goes bad. I’m down to about 40 bales and just went through about 20 bales the last few weeks.

[BoyleHeightsKid]

If it’s just dustly on the outside, just mist it and feed it outside. I have trouble with this as I don’t have enough air circulation where I keep the hay, so when it’s warm and humid the bales on the outside can get dusty. I beat as much of it off as I can, then mist it before I put it out.