pepperhead212
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Location: Woodbury NJ Zone 6B

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
Dave

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Gary350
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Joined: Mon Mar 23, 2009 5:59 pm
Location: TN. 50 years of gardening experience.

Re: Hill Hardy rosemary really is cold hardy!

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

Re: Hill Hardy rosemary really is cold hardy!

Tuscan Blue?
Learning never ends because we can share what we've learned. And in sharing our collective experiences, we gain deeper understanding of what we learned.

SQWIB
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Location: Zone 7A - Philadelphia, PA

Re: Hill Hardy rosemary really is cold hardy!

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 5:52 pm
Location: Woodbury NJ Zone 6B

Re: Hill Hardy rosemary really is cold hardy!

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
Dave

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