pepperhead212
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Location: Woodbury NJ Zone 7a/7b

Hill Hardy rosemary really is cold hardy!

Last year I got 3 Hill Hardy rosemary plants from Richter's, after my old rosemary died, after a severe cold snap, and the wind blew the cover off of the hoop house. I couldn't get out to re-cover it, and it was gone in one night!

I planted two of the plants in the ground, and one in a 4 1/2 gal fabric pot, and the one in the pot took off! I figured that I would leave the ones in the ground in place, and when it got below 20º (the usual low limit for rosemary), I'd cover one with a trash can, and a brick or two, to weight it down, and leave the other uncovered, to see how resistant they really are.

Naturally, I forgot to cover one Sunday night, when it got down to 11º (maybe lower - that thermometer, though away from the house a ways, is on a brick post, so it may hold some heat), and only up to 16º all of Monday, with winds up to 35 mph., and back down to 14º Monday night! :roll:

Amazingly, both of the plants look fine! Not a hint of freeze damage, so this variety must really be cold resistant. I will still try to cover the one, if we have another cold spell like that. I did cover it on Thanksgiving - down to 16º , and the only other time this season that got in the teens.

The sage looks worse than the rosemary, but those can die back, and grow back, and I usually cut them down to the ground, once a cold snap does them in. I cut some of this off today, for a dish I just saw a recipe for.
ImageIMG_20190123_120437972 by pepperhead212, on Flickr

Here is the one in the pot, which I even brought in from my back porch, wondering if it would get below 20 there (only got to 24º, turned out). Not a great photo, due to intense sun outside, but it shows the size of it, with a 5 gal pot next to it, for a reference size. And I have probably cut off at least as much as you see there, before I brought it into the porch, and since.
ImageIMG_20190121_103422249_HDR by pepperhead212, on Flickr

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Gary350
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Joined: Mon Mar 23, 2009 1:59 pm
Location: TN. 50 years of gardening experience.

It was 8 degrees F here my Rosemary is still alive but I don't care, I wish it had died. I have a no flavor plant it has as much flavor as dead sticks. Next year I will buy what I had 5 years ago name starts with the letter T. I want to say Tucson but that is not it.

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applestar
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Location: Zone 6, NJ (3/M)4/E ~ 10/M(11/B)

Tuscan Blue?

SQWIB
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Location: Zone 7A - Philadelphia, PA

I had one winter over a few years ago, I tossed a fluorescent light next to the plant, covered with some leaves and a blanket and laid a few rocks around the blanket. It really grew the following year, last winter I did nothing and it died, I grew this from seed.

This year I took some cuttings and rooted them and have them on a window sill most died but one is hanging in there. I did cover the one outside with pine needles and leaves, we will see.

pepperhead212
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Joined: Wed Oct 15, 2014 1:52 pm
Location: Woodbury NJ Zone 7a/7b

This is definitely the most cold hardy rosemary I have tried! Arp, a bluish variety, which I tried years ago, died at higher temps than this (even though some said it would resist 0º), and I really didn't like the flavor of it.

Those rosemary survived, including the uncovered one! It got to 5, 6, and 9 degrees here three of the nights, and two days it did not get out of the teens, which would have killed a regular rosemary. It wasn't that cold when my old one died - just low teens.

Here are both of them, the covered one on the left:
ImageHardy hill rosemary by pepperhead212, on Flickr

And a closer up of the uncovered one - a few brownish tips on some leaves, and a few turned a little purplish, but not like the dead, brown ones that extreme cold would normally cause:
ImageUncovered hardy hill, after 5, 6, and 9° nights. by pepperhead212, on Flickr



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