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ravenea_rivularis

Overwintering rosemary hints...?

ravenea_rivularis
18 years ago

Hello all,

I recently purchased a 7" tall rosemary plant, labeled "tender perennial-hardy zone 7". The latin name given on the tag is Rosmarinus officinalis. This was bought as an experiment, so it is slightly expendable (i.e., you won't find me in trama therapy if it dies this winter), but I would be grateful for any tips any one has on wintering this over outside, against a south wall, in zone 6b, exeter, rhode island. I was thinking about mulching it, then covering the mulch pile with some heavy duty outdoor type plastic, and then mulching over that again; the second layer could be straw. Any ideas? My girlfriend and I are very new to herb gardening, and need all the help we can get. Thanks for reading. :)

~derek

Comments (31)

  • jannie
    18 years ago

    I am in NE (allegedly zone 7) also. I can't give you advice on overwintering outdoors, but I can tell you my experience: TWICE I tried to bring rosemary inside for the winter. Both attempts failed. No mattter how much sun and water I provided, they died. They turned yellow, then crisp, then died.

  • jlgreg
    18 years ago

    I've had a lot of trouble doing this too. My herb garden is in a moderately protected south facing area. I've tried heavily mulching my rosemary and leaving it in the bed, but it always turns brown and dies. Probably because rosemary is only winter hardy in zones 8-11. Anyway, I've had some success with bringing potted rosemary indoors and placing it in a south-facing window. It needs lots of light watering and frequent misting because forced-air heat dries everything out...

  • debbie814
    18 years ago

    I've had success with bringing potted rosemary indoors and placing it in a south-facing window. It does need watering throughout the winter. Good luck!

  • nygardener
    18 years ago

    The prostrate (trailing) kind of rosemary seems to overwinter better indoors than the upright kind. The 'Arp' variety is supposed to be more winter-hardy outdoors than others, though reports on how hardy it really is are mixed. Your siting and mulching ideas sound like they'll offer it good protection, though I think a tarp may smother it or cause rot.

  • tompy
    18 years ago

    I too have potted rosemary and brought it inside and had very good results. Infact i got about 5 inches of growth and some blooms.

  • rouan
    18 years ago

    I've also overwintered Rosemary successfully. I read a hint in one of the herbal magazines that suggested planting the rosemary in the same pot as a geranium. The reason stated was that the geranium would take up any water that the rosemary didn't need, so you don't have to worry about overwatering. Aside from that, I keep the rosemary/geranium in a south facing window. It's been through 2 winters here in upstate NY (zone 4b)and is still going strong.

  • ravenea_rivularis
    Original Author
    18 years ago

    Thanks all for the advice...though I'm still not sure how to do this OUTside. As it's a zone 7 plant, and we're 6b (supposedly 7a as of this year), I thought with a little protection it would be ok. I think I'll probably end up trying my mulch-or-straw idea.
    Thanks again
    ~derek

  • gw:cathy-c
    17 years ago

    I love rosemary - it is my favorite herb. I'm in Upstate NY.

    â¢First I tried to bring it inside under gro-lights but the second winter it died of powdery mildew. It also tends to get leggy from lack of light regardless.

    â¢Then after the next summer outside, the rosemary had grown through the bottom of the pot into the soil, so I tried planting it in the ground and mulching it and putting a plywood "V-tent" over it with burlap around to protect it from weather. I almost killed it since it really needed water and only the one branch peeking out the edge lived! Then it came back for the summer. So the next winter I mulched it, put the plywood V-tent on its side and burlap over the top so snow moisture could get through. In the spring I found it dead since a rodent took refuge in this protected cozy spot and gnawed around the trunk!

    ⢠After last summer, in November I took my potted rosemary into my unheated breezeway where there is some indirect light. I figured it would get cold enough to go dormant and protected from weather. It dips to about 10 degrees here, so I was unsure. I watered it sparingly just enough to keep it from completely drying out(about a cup a month). It worked! It stayed green but didn't grow, and I didn't snip any.

    ⢠After this summer, in November I will cut about 2" off the bottom of the roots and 2" of the sides before repotting it in the same pot and pruning it back about a third. I'll try to give it enough time to grow back a bit before I bring it in to the breezeway again. It is about 2' by 2' right now.

    I hope you have not given up!! You can do it. Good luck!

  • zuniform
    17 years ago

    Sounds like you have a plan. Planting next to the wall certainly will give it some protection. I have two rosemaries, both survived last winter. The first, variety "Salem" is upright and was planted next to a south wall, like yours. I did not protect it at all, but pruned away most of it in March, leaving a few stems that still looked green. It is now about 10" high. The other, prostrate "Arp", was left in a small pot all winter and somehow survived. It was a mild winter, though.

  • oldroser
    17 years ago

    I've got five potted rosemary plants at the moment - some of them four and five years old. All different kinds. They get repotted in Septmber and brought in and put in south window before frost. They need to be kept moist but never really wet. I use just a regular potting mix and they do fine. The one time they had mildew, neem oil took care of it.
    I was away for a week and left a sprinkler going on a timer for the potted plants - an hour each morning. So the rosemary was really watered but they are doing fine (standing on a gravel driveway) and several are blooming. The trailing kinds seem to bloom most.

  • narcnh
    17 years ago

    I'm in zone 5 and have tried a couple of times to keep two supposedly hardier varieties of rosemary, Arp and Hill Hardy, alive outside to no avail. Both were in the ground next to the south-facing wall of my house in a protected nook, but no luck. You may have better luck in zone 6, but be careful with mulching. You may keep the plant protected from the cold temps but kill it with excess moisture. The tarp might be too much. I would just try some straw around the plant. On warm days (anything above freezing), remove the straw and let the plant get some light and some air movement.

    I have a standard, potted rosemary that is five (at least) years old and comes in every winter. South-facing window, no misting, infrequent watering. Basically, benign neglect. Besides a lot of light, I think the secret is not to overwater. Last winter I posted pics of the plant in full bloom in the middle of the winter. Last fall I waited until temps were down into the mid-20's at night for several nights before bringing it indoors. The pot was frozen solid, but the plant was unaffected.

    narcnh

  • beabuz
    17 years ago

    I think rosemary does well in winter if you live near the ocean. The salt from the ocean prevents freezing of the plant and it may even protect it. Might sound crazy but when I lived in Ventnor, NJ, my rosemary plant was thriving. Would get a bit brownish during really cold days/night but returned to its glory in spring.

  • granite
    17 years ago

    My rosemary is planted on the EAST side of the house, but located near the brick wall of the house and protected on the north side by a spruce tree. It has been there at least 6 years. In very cold years, the center of the rosemary bush dies from the cold current coming around the spruce tree and whipping along the house to cross the rosemary. I don't wrap the bush, I do trim it as I use the rosemary. In the spring I remove the winterkill areas and trip back the tips.

  • bobell
    17 years ago

    I have had sucess with my rosemary by planting it next to the house on the east side. That's it, I don't wrap it or anything. I am in the NW corner of Arkansas, also a zone 6. I did plant ARP and another cultivar side by side and I can't really tell a difference in the hardiness. I have never had luck with bringing them indoors. Good luck with yours

  • maifleur01
    17 years ago

    I have tried over wintering with no luck. When I see the rosemary in the Taos-Santa Fe area I could just weep. Three-four feet tall and round. It gets just as cold there but less humidity.

    Things I have noticed mulching seems to cause the leaves to rot. Pine needles might be better than what I have available.
    Bring it in and it is too dry.
    Putting it on a saucer larger than the pot with rocks between the pot and saucer with water just to the top of rocks but not covering seems to increase the time before it dies.
    Outside it seems to like rock or bricks that hold and reflect heat.
    If the plant lives to January (one did) the freezing and thawing of February will crisp the remaining leaves.

    All this said there was a fair sized rosemary plant behind a garden gift shop in Excelsor Springs, MO that had rosemary plants that have withstood our normal below zero temps and looked really good the last time I was there.

  • mogardener
    17 years ago

    Several years ago, I bought 2 Hill Hardy rosemary plants from a greenhouse in Columbia MO thinking I would plant one in a hoop house and pot the other to be sure one would survive. The one inside went toes up despite my best efforts but the one in the hoop house continues to do just fine. It's survived below zero temps in that hoop house which protects it only from the wind. We remove the hoop house cover in the warm months and use the space as normal garden beds. In winter, we grow the herbs (thyme, sage, parsley, oregano, chives, that rosemary) and cold hardy salad greens under cover.

  • scargod
    13 years ago

    I am in 6B and for four or five years I have brought the rosemary plant in. It is three feet in diameter, in a 5+ gallon pot. I don't know the variety. It seems mostly dormant while inside, but it did bloom one year. So far this winter I have left it outside. One or two mid-twenties nights. It's still happy!
    I remember living in North Texas (8A-7B), and a neighbor having a rosemary "tree" as big as a Volkswagen. It gets down in the low teens occasionally in N TX (but the ground rarely freezes). It lived on and on...

  • Rochefleurie
    13 years ago

    I use to find it very difficult to overwinter rosemary inside but these last few years I have used a very simple technique that works beautifully for me. Here is what I do: in the fall, I keep the pot outside in a protected area for as long as I can. Before temperatures get to the freezing point in the day time, I water the pot a last time and move it to a crawl space under the house (a root cellar would work just as well). The important points are that the storage area does not freeze and stays humid. The plant gets no light and is not watered all through the winter but, surprizingly, survives quite well. I use the same technique for an Aspidistra.

  • jensoden77
    10 years ago

    I live in Kansas in zone 6a. I planted the same variety of Rosemary as you during the summer of 2012. I planted in a two tiered herb garden on the South side of my house fully expecting it to die over winter. Low and behold it started to grow next spring. Early that spring I trimmed it way back to about 4 sprigs. Now it is HUGE. I placed a brick beside it to show you-it is almost a bush now. I have lots of luck with my herbs in this spot! (It is yellowing a bit in the picture b/c it is fall, but it did the same thing last year).

  • surya55_gw
    10 years ago

    jensoden- what a beautiful bush you've got there. all -thx for sharing your tips on how to keep it overwintered.

  • seysonn
    10 years ago

    I had rosemary in GA (z 7b), it over wintered in the garden. The winter lows get down to about mid teens down there. In PNW, they are grown as shrub in a lot of places, like box wood. So I can get as much as I want. I use it mostly as air freshener under the sinks, ...Not much cooking with it. I prefer thyme and oregano.

    Another thing is that I think there are COLD HARDYier varieties. So for you folks up north maybe its worth looking into it, if you like rosemary that much.

  • gjcore
    10 years ago

    This is my rosemary setup here in zone 5. Originally I just had the smaller hoops in place as a temporary thing until I could figure out what I was going to do. Then I started toying around with these EMT hoops and thought 2 sets of hoops are better than one. Really though I'm still not sure how I'm going to make it through the winter. Might need to bring some inside, others to the garage or try to find more space in my old school coldframes.

  • monarda_gw
    10 years ago

    I have kept potted rosemary indoors over the winter for many many years. I learned from trial and error, involving many many failures.

    Here is what I found. Rosemary is very intolerant of drying out. If it dries out -- that's it. It won't recover. On the other hand it likes perfect drainage. So check the soil frequently with your fingers to see if it is damp.

    The thing about rosemary is that it is fast growing and wants to be five foot tall and wide. So when it is happy, its roots fill up the pot fairly quickly. Once they fill up the pot, it dries out in a trice. So you need to prune the roots once in a while or give it a bigger pot with more room. Prune the roots and the leaves (for cooking) to slow it down. Otherwise, a happy plant will suddenly be dead in the morning with no warning. I also find this to be true with myrtle in pots (love this plant).

    Indoors, rosemary should get all the light you can give it, and circulation of air, if possible. The cooler the room you keep it in, the better. A chilly vestibule is ideal. A fan and humidifier in the room are not a bad idea. Rosemary thrives in a breezy seaside environment in its native Mediterranean.

    Outdoors, I once kept a rosemary in a big container in very light potting soil alive for several years at my cousin's cottage on Long Island. It was planted in a huge flower box with other winter savory and thyme. The container was right against the house in semi-shade near a window so got some warmth and shelter. The plant didn't look very good when Spring came around though and I doubt it was worth it.

    Rosemary is extremely easy to propagate so don't feel too bad if you kill it a few times before finding what works for you and it. It's great with bland meats like pork and chicken.

    The idea of growing it in the same pot as a geranium is intriguing to get rid of excess moisture is intriguing. I am thinking also of trying something like that with amaryllis, which also hates excess moisture.

  • balloonflower
    10 years ago

    gjcore: Looks like a nice setup. I'm interested in seeing how it works for you. I'm in Denver, and do bring mine in during the winter and am getting better all the time. Have you thought about stacking some hay bales around your setup for good wind protection? They may help keep some of the temperature variation up and down more level.

    The Botanic Gardens has a beautiful Arp bush on the side of the conservatory that I am so jealous of. The concrete provides a good heat sink for it, with south exposure. I also know of another here in Denver that has a bush on the south side of a brick garage and survives winter well here.

  • gjcore
    10 years ago

    Hay sounds like a good idea. Maybe next time I'm down in Parker I'll pick up a handful of bales. I also have been using a space blanket tarp and an old sleeping bag thrown over the inner hoops at night. With the big chill coming in the 5 day forecast I thought I needed a bit of external heat added so I strung a set on incandescent Christmas bulbs around the edge of the pots. I'm also considering buying 4 of the space blanket tarps from Big5 and duct taping them together to throw over the outer hoops.

    My feeling is that the longer I can keep them outside the better off they will be unless of course they freeze and die. I have about 10 rosemary plants growing in the open garden and this will be their 3rd winter. I came across rosemary at various different houses that made it through winters and asked the homeowners if I could take cuttings. It seems to be the best places outside are at least somewhat sheltered and also in a location where snow tends to not accumulate.

  • wally_1936
    10 years ago

    If nothing else works take cuttings for starts next year. I have never had a problem making cuttings living inside for many months on end.

  • gjcore
    10 years ago

    Yes making cuttings has always worked for me to get through the winter.

    I had to move my 20 or so larger rosemary plants into the garage for now. I don't have enough confidence in my double tunnel with nighttime lows below zero. Drenched their soil and sprayed them down with neem oil today and then will probably put most of them under grow lights in a south window.

    Might move them back into the tunnels when the temperatures are back to normal.

    I have about 100 smaller rosemary out in the coldframes which should be fine. I sell most of my rosemary at a plant sale in spring.

  • claydirt
    10 years ago

    Thank you. Nice advice.

    Over-wintering rosemary in pots, I've had one failure and one success. The success (as I recall) was when we had a very mild winter. Every day that was at or above freezing, the pot would go outside and sit on the patio. At nigh, when temperatures dropped, it came back inside.

    I may try the hoop approach... but I fear it is too late this year. My rosemary has already been fully exposed to single digit temperatures.

  • grandmamaloy
    10 years ago

    Your question brought to mind a question of my own...How big is that rosemary plant now? If you want to ensure its survival, you may want to dig it up, pot it and bring it indoors for the winter, replanting it back out in the spring. However, once it gets larger (too big to transplant & with well established roots), you may have success just mulching it really heavily. I don't think I'd use plastic and then more mulch because that will trap moisture and the plant & its roots will be unable to breathe; they will probably die. I would just mulch it extra heavily, especially since you live above the perennial zone, though having it against that south wall will help with some heat. Good luck and stay warm yourself waaaay up north there!

    Here is a link that might be useful: How to Overwinter Herbs

  • gjcore
    10 years ago

    Just an update on the rosemary growing in the tunnels. I took it indoors for a while under the grow lights and 2 of the 8 died I believe from drying out too much. So back out in the double tunnel they went. Been through some really deep freezes recently -10F to -15F and they made it through and are mostly still looking very green. Some of the containers got at least partially frozen so hopefully that doesn't set them back.