Protecting plants from freezing weather

I planted some rosemary in the front yard a year and a half ago. I know it will grow up here, as I was inspired by a very large bush in Friday Harbor. When I planted the rosemary, they were maybe a foot tall. Last Winter brought snow. One plant, the smaller of the two, survived nicely. It has just a little bit of shelter from an arbor vitae next to it. The other one is between two bushes, and half of it died. The surviving half has been doing well. (There was also a plant in a pot on the back porch, and only one sprig survived Winter.) I’m guessing that it was the snow that did the bulk of the damage, but I wonder about freezing roots.

It’s 25ºF this morning, and I wonder how I can improve my rosemary’s chances of survival.

Across the water from you- I have wintered fuchsias and occasional other tender plants over by trimming quite a bit off, and placing up to a ten inch pot in a 30 gallon muck bucket full of manure. then I put an old sheet over it. It’s been down to 22 recently here, but the winter I kept the pretty fuchsia alive was one of the colder ones, down to single digits. I wish I had done that with my stevia :confused: but actually didn’t have the required bucket of manure. Or you can pile mulch around them. I buy a new Rosemary every three or four years …

There are a number of things you can do to help borderline-hardy plants to survive, including:
[ul]
[li]Choose a hardy variety - in the case of Rosemary, there is significant variation in hardiness between varieties[/li][li]Provide good drainage (cold and wet at the roots is generally more harmful than cold alone)[/li][li]Plant against a south facing wall (the wall stores the sun’s warmth during the day and radiates it at night)[/li][li]Provide shelter from wind - even a mesh screen or the bare twigs of a deciduous shrub can mitigate cold winds enough to make a difference[/li][li]Prevent roots from freezing by mulching or planting evergreen ground cover[/li][li]If extreme conditions are expected, wrap tender plants in straw and sackcloth to reduce their exposure to frost (but this is a high maintenance regime)[/li][/ul]

Mangetout is da Man.

(snerk)

in freezing ground environments the mulch will delay freezing, not prevent it. what it does is prevent it from thawing until it actually is warm in spring. unmulched it will thaw and refreeze a number of times which causes much damage.

other good thing for plants is to cover the above ground with a pot, cone or wrap. a dry winter wind can damage where the new growth should occur.

also agreed with getting a variety that is survivable outdoors at your location, unless you go to extremes to keep it alive.