I don’t use a lot of hay. My pony gets a round bale October/November, and that usually lasts until grass starts growing. So I want a bit to tide over rough spots.
A few years back I welded up a hay storage bin. About 5 feet square, and a bit over six feet high, whatever would fit out the shop door. I used 3/4 inch square tubing for the frame, and 2×4 welded wire for three sides, with the front open above a ‘keeper’ bar about 1 foot up. This worked pretty well with loose hay.
Where I live is old-growth pasture. The local story goes that it was virgin prairie, and has never been plowed. After 70 years of grazing pasture use, I doubt that there is much original prairie grass left, and Johnson Grass has moved in around the buildings and in the pony’s pasture. Johnson grass was introduced to Oklahoma for hay and pasture, and does well at both. The problem with Johnson Grass is that it is very persistent if you want something else to grow there, and it tends to spread. Widely.
So what I have around the buildings to harvest is a mix of short grasses including cheat, and Johnson Grass, mostly, and a few patches of bermuda grass, sometimes occupying the same space. Next to the driveway is a solid stand of Johnson Grass. When I cut it early, it comes in solid bermuda. Cut that, and it is Johnson Grass again. But it mostly stays green. . .
I have a book on ‘farm implements you can make’, from the 1800s, that shows a wood frame for baling hay. This spring I got to thinking, and got out the two-hand scythe a friend cobbled up out of stainless tubing and regular handles and a brush blade.
The first part of making hay, after the planning and hoping, and watching the grass grow, is cutting. I am still learning to use the scythe, but I did manage to put down some short and tall grasses.
Next is curing. Curing is when sufficient moisture leaves the hay leaves and stalks, so that the hay is dry enough to store well, keep it’s nutrition value and not decompose. Hay put up too damp can rot, and at times generates enough heat to catch fire.
The sun and open are do the curing. I leave the hay a day or so, depending on the condition of the hay and weather, then get out the hay fork (four tines, wider than a three tine or manure fork) and turn the hay so the stuff on the bottom is exposed to that curing sun and breeze.
For short stem hays, a day or so after turning the hay may be ready. Long and coarser stem hays may take another day or three, and another turn or two.
Almost anticlimactic is gathering the hay and tossing it in storage (for loose hay) or baling.
Dad baled hay, and my neighbors bale hay. This includes a tractor, and first a mower or conditioner, then a rake, and finally a baler. The result is, usually, a very consistent stream of round or square bales laid out in the field, to be gathered and stacked until needed.
I don’t have that kind of equipment. I have a ball of Sisal twine, a blue plastic muck bucket, a box knife, and a hay fork.

Baling implements
Using the same fork I used to turn the hay, I laid some hay on the bucket and pushed it down in, about centered. A couple-three modest forks full, and it is time to mash the center of the bundle of grass together, grab one end of the twine and reach down one side of the hay to the bottom, reach down from the other side of the grasses to the bottom of the bucket, grab that twine, and pull it on around. A quick (!) square knot while mashing the center of the bundle together and pulling the twine tight, and cut off the bale of hay. Lift the bale out (it looks a lot like a bundle of grass with a string around the center), and repeat.

Twine just about wrapped around bundle
When I tried it using the wheel barrow instead of the muck bucket, it was easier. The wheel barrow allowed for a bit bigger bale (fewer baling operations), and reaching around the bundle was easier than stuffing my arms into the muck bucket full of hay.

My bale of hay.
The hay fork is useful transporting the bales, too, as I can usually stick the tines through two stacked bales. I estimate the bales range between small muck bucket size, about two pounds of short grasses, and maybe ten pounds for a moderate sized wheel barrow bale. Toss them into the hay bin, and let them complete airing out.
My problem with Johnson Grass hay is the weather. We have been getting rain showers with little accumulation, just enough to wet everything, and that delays curing. This isn’t great, because the wet/dry cycles are letting the sun bake out the nutrients in the hay, and keeping the moisture up so I cannot gather the hay yet.
The pony stands about three feet, five inches. Johnson Grass runs from four feet to seven feet. The pony likes to nibble the tender ends of the grass. So fully grown Johnson Grass doesn’t feed the pony that well. Where I have cut the Johnson Grass, the new-growing returning stems are short, and the pony (“Little One”) gets a better nibble in. And I get (some) hay put by for later, if it is needed.
I reckon that gathering hay is something folks with livestock could be considering. Hay from along fence lines, along unkempt roadways, on unused lots. Chickens will eat some hay, and use it for bedding, hogs eat hay and use the bedding, cows, goats, and sheep, too. Learning to hay takes practice to learn the grasses you harvest, the tools you use, the process and exceptions of curing, and the techniques for transporting and storing hay.
I turn 59 this year, with back pains and lowering heat tolerance. Gathering in fields at a time is for the young folk. I don’t have a lot of storage, and find the hour or two a day very satisfying (that is, I don’t want more, at the time).
The sisal twine I got from Big Lots, in the garden section. It is light, strong, and traditional for haying. The fork I picked up at a farm sale, a treasure that too many people decided isn’t needed, since they went to crops-only, or automated livestock farming. A modern three tine fork can run from $30 to $40 dollars, hay forks and the larger field hay forks would be much more expensive.
Last year I sharpened the scythe blade with a flap sanding disk on my angle grinder. Last winter I ordered a ‘scythe stone’ from Amazon.com, and it works a wonder. The package the stone came in mentioned wrapping the stone in cloth. I whacked out a six inch wide strip from the leg of a pair of rag-bag bib overalls, about two and a half times the length of the stone (about 10 inches by 1 1/2 inches). I lay the stone in the center of the cloth, lengthwise, and fold the top and bottom over, then the sides. I can stick that wrapped bundle in my pocket for convenience; the stone unwrapped would catch and hang in my pocket something fierce.

Little One, in Johnson Grass just starting to grow