I want to try going without blanketing this year to give it a try. I live in Virginia(closer to the ocean and it only snowed a couple times last year) and it gets cold, but not crazy freezing like some places. My horse is a healthy eight/nine year old. He grows a winter coat even when I blanket. I do have a question though and any advice is welcome.
He is pasture boarded so he is out 24/7 with a bunch of other horses and cows. They can huddle up against barn walls in poor weather but I never see them do so. It is a large pasture though and is outlined by spacious woods with heavy coverage. Which is where they are usually found when it is super hot or rainy. Is rain a huge threat to a full-coated horse during winter? I'm not sure if the trees provide 100% cover or if he'd even use them all the time.
1. Good for you. It has to be pretty brutal by natures standard (not human standards), meaning the healthy, well fed wild animals (deer, coyotes, etc) are freezing to death in significant numbers before it will to cold for a horse to handle. If left to nature they will grow a good coat and actually be better off than they would be if blanketed. I've never blanketed a horse any place I've been from central MA to southern AZ.
Even in the most brutal climate (I'm sure there are places in Alaska, Siberia, etc... that it might matter) I'd rather have a place to bring them into at night and let them use their Winter coat naturally instead of blanketing them.
2. I would recommend having some place that they can get good cover from. A simple 3 sided run it will work. While the majority of the time mine have always preferred to stand around trees (or even out in the open) they do at times go into their shelter. No rhyme or reason to it. Some in and others out, all in or all out.
It's not that rain is a "threat" to them, because I've seen them stand in a freezing rain (even go back out in it after being brought in) or that trees only offer limited degree of protection from rain, but there just are times that they will (for unknown reasons) go into a shelter if it's provided. However, they'll manage with whatever they can find. Barn walls can offer shelter from wind and eves may offer some (often better than trees) protection from rain. They'll use all these if they feel the need and it's available.
They can still grow a Winter coat (a lot or little), but not blanketing them alsos them maintain the ability to "puff out" their hair to hold air and keep warmer. Blanketing prevents that and after a time they won't be able to do it (it's not permanent, but I've seen it mess them up for most of a season) which results in them actually being cold if you don't maintain sufficient protection after messing with how they were designed to keep warm.
Mother nature equipped the horse with what it needs to deal with cold weather. It's only people who think we know what's better than nature, which designed the horse to deal with various climates.