Not sure what rootstock your Redhaven is on. Semi dwarf may well mean standard. Generic tags like this don't mean much.

Ignore the tag and prune the tree to a height that fits your expectations.

I've no idea how to keep the cover on the tree. Understand to protect from leaf curl, the cover must be on before bud swell and taken off after the leaves emerge. After that a cover would do nothing to prevent the disease. Therefore once you can see the fruit has formed, a cover is no longer necessary for leaf curl.

Last year you left your cover on too long.

I've never heard of covering a tree to protect from peach leaf curl- is this something done out west? I'd be worried that by cutting off air circulation you'd be serving the fungus as it probably doesn't need rain- just the 100% humidity that comes with it. Got any research to back up this approach?

Covering a peach to prevent curl is not a western practice, or anywhere else I have heard of. Fungus does not fly in on the back of a moth. Fungus is everywhere and a fungicide is needed to kill it. Your last chance is a copper spray at first sign of bud color. Sometimes the weather will not give you the "last" chance and so it is better if you have sprayed at leaf drop and again in January. Al

Thanks for the answers. Especially about the rootstock Olpea. I think I will prune it to the size I want and see what happens. We have a problem on the west coast with cold wet springs and the curly leaf can be controlled by keeping this cold, wet rain off the tree. Unfortunately, I tried with plastic and the wind knocked the plastic off the frame and lots of the small developing peaches were also knocked off by the plastic. Bad experiment. So, I think I should prune and then dormant spray. It is still cold here so I still have time to spray.I truly appreciate the advice.

Your welcome Dotty.

Hman and Calistoga,

Covering for the peach tree is a recognized control method for leaf curl, not just on the West Coast, but in the East as well. See URI homeowner fact sheet below.

It's not an approach I would use, but I've read accounts of people who have used it with success.

I suspect the reason humidity is not enough to perpetuate the disease is that it takes rain to wash the fungus in the bud scales.

It's not unusual for different fungi to require different amounts of moisture to cause symptoms. Recall powdery mildew only needs dew to sporulate, whereas, for the most part, scab requires rain.

Here is a link that might be useful: University of Rhode Island homeowner fact sheet

Thanks OP. Sure seems like a single copper spray would beat trying to keep a tree covered from rain.

"Sure seems like a single copper spray would beat trying to keep a tree covered from rain."

No argument there. I'd never consider trying to cover a tree to prevent disease unless there was no other alternative.

However, I assumed Dotty was going to such great lengths with covering because she was diametrically opposed to spraying, so I was advising her according to that philosophy.