A quick google search got this link and the instructions seem easy enough.

Here is a link that might be useful: how to age horse manure

I put it on straight from the barn two or three inches deep. Just don't get it too close to the canes. I've never had any problems doing it this way.

Like Floridarosez, we use horse manure directly from the horse, using it in precisely the same way.

We do water it in well, and the response from the roses is extraordinary.
Some people will tell you that it must be aged, but FRESH horse manure has always been used on roses.

There's a really delightful passage by Dean Hole, on this precise thing. He regarding the deposits made by a guest's carriage horses as unexpected treasure.

Jeri

My mom has told the story that my grandmother and the lady across the street used to fight over who got to pick up what the horses/wagons left on the road. As in "She stole it! It landed on MY side of the road"

My only problem with fresh horse manure is that my dogs like it too much. Unless aged a bit they dig it up, seems like it loses flavour to them with time. Wonder if this flavour is what the roses like as well?

I age mine in bags just started a couple of months ago.

Southcountry, we have a famous restaurant here called the Chalet Suzanne. The food is amazing. My veterinarian says that horse stalls and kitty litter boxes are the Chalet Suzannes of the doggie world. I guess that would also include my garden.

I mix it up with water and everything else in 32 gal. barrels, let it steep and water the roses with it. Here there are horses and partially rotted horse and cow manure. Back in CT I got alfalfa but if you can get manure, why bother with alfalfa.

No weeds as a result?

Careful about aging it in bags. If they are plasitc or otherwise prevent air from getting to it you can end up with anerobic composting--or fermentation--which can lead to a stinky mess. Much worse than a humble barnyard smell.

Not that I have much of a nose for horse poop anymore as I'm pretty much immune at this point, but I don't think it is very odiferous after a week or so. A stable that has it in "abundance" might likely have a pile that is old enough not to smell too fresh.

subk3, I researched it first, before I did it, so yes, all the bags have holes.

OMG cat litter!!!! Truly, this familiarity with the end results of digestive systems speaks of a deeper (more insane) love of roses than I am prepared to engage with. For a fastidious nation (regarding shower usage and toiletry sales in the US), you sure are happy to grub about in poo!!
I have used manure in the past (and definitely never younger than 6 months on an open heap) but usually as a tea since the practice of putting anything around roses, including proprietry fertilisers has always been something of a conundrum because I do not have any visible space. I do not love the practice of heavy mulching since I do not wish to see soil, mulch, hay, bark, and definitely not poo in any form.......I want plants...and more plants....not spaces for fertiliser which can be either dug in at the first or watered on throughout a plant's life.

But that's just me.

On a less personal note, using manure of any type has become a complete no-no here in the UK unless you are absolutely sure of what pasturage has been used at every stage of a horses (or cows) life and can guarantee no broad leaf weed killers have been deployed. In the UK, we certainly cannot and since most horse-owners have to buy hay at least some of the year, only a fool would risk putting the resulting manure anywhere near their plants.....unless they are completely OK with manure contaminated with clopyralid/amypyralid or any of the later broad-leaf weed killers after 2.4.D. Of course, if you have access to your own horses and own grazing meadows which are unsprayed, then fair enough, but sadly, manure, in whatever form, has become a thing of the past for may gardeners in the UK since we neither trust nor believe farmers to read the tiny print on the labels stating not to be used when hay is going for silage.

"For a fastidious nation (regarding shower usage and toiletry sales in the US), you sure are happy to grub about in poo!! "

hmmm...I think my willingness to hop in the shower more often than average might actually be related to my willingness to grub about in poo!

Well folks, I use kitty-poo, and the roses LOVE it! I have 4 fur-balls inside and they all do their patriotic duty for their mama...I scoop daily and my little yellow poo-pail goes right out to the garden for my 150 +- roses... so there.... if I nag my son he takes me to a stable and we shovel some horse-poo and bring it back in his pick-up truck and it gets dumped right out into the garden just like that....LOL, sally

eeeeuw!

The only thing to be thankful for, regarding my daughter's anti-social fleabag is the fact that she (the cat) chooses to go off to some distant bushes, nowhere near my tiny garden. Words simply fail me to describe the horror of rooting around in the undergrowth and sinking your hands into a cunningly concealed cat offering.....and I have lain in wait with a range of weaponry including my trusty Black Widow catapult (obviously well named) to deter any local felines from attempting to 'gift' me with such an offering.
Truly Sally, your love of roses is as deep and boundless as the ocean (while mine approximates a muddy puddle).

Well thank you-- but I don't 'root around' also I wear gloves,and w/a bad back I'm hardly ever 'down there'...., actually I'm the only one that realizes there is poo out there, there is no smell and nothing visible, kitty-poo is a natural quality no different from other organic fertilizers, cow manure, horse manure, chicken, rabbit....milorganite.....etc... it all makes the roses grow and thrive, and that's what it is all about.... also, I am a cat-lover, my kitties are like my children, it has always been so ! cheers, sally.

It's actually rather funny that there are people that turn their noses up at homemade/fresh compost from a private source, but will run out to their local box store and buy something that is the same thing but in a plastic bag--except with lots of yucky stuff they feed/inject into animals in a feed lot plus goodness knows what else.

And they feel better about it!! :-0

Score!!!!

The boss is thinking about hiring a guy to do the "collecting" part. I offered the trash cans and the hauling off part.

Bet the roses and the pumpkins will be happy. (and the compost bins will be full)

well, Sally, I would happily use (uncontaminated) manure from an animal which was essentially vegetarian but fresh faeces from a carnivore is just not going to happen (cos I do root around continually)......or I could just poo on them myself -and when my composting toilet is up and running in the woods, I will be using 'nightsoil'- but you can bet it will have composted down for half a year (and not used on edibles either). Perhaps the cat-litter does something to 'enhance' or remove the terrible whiffiness.....or perhaps our cats are just naturally stinky when crapping, (my old collie sure is) but I honestly admire your fortitude and can-do attitude.