According to the hardiness maps we are too far north (zone 5) to grow rosemary as a perennial.Check out the National Arboretum located in zone 7 for more details on their rosemary hardiness study.Though challenging to over winter inside you have a better chance for success and even the dried dead plant is fragrant. .
How to Grow Rosemary Plants
Space rosemary plants 2 to 3 feet apart in an area with abundant sunlight and rich, well-drained soil with a pH of 6.0 to 7.0.Before planting, set your garden up for success by mixing in several inches of aged compost or other rich organic matter into your native soil.Promote spectacular growth by feeding rosemary regularly with a water-soluble plant food.Harvest rosemary stems by snipping them with sharp gardening shears. .
So how cold-hardy is Rosemary?
According to everything I’ve read, it can’t survive freezing temperatures – yet here we are in late January after an unusually wintery December, and this specimen on my deck is just fine, thanks.And from Fine Gardening Magazine we learn that: “In the fall, when the temperature dips to 30ºF, it’s time to bring rosemary indoors.”.So I posed my burning questions to Kerry Kelley, Homestead’s manager of annuals, including herbs, and she replied:.Some people with zone 8 microclimates (Capitol Hill, inner city Baltimore, close to the bay, or just a warmer, protected spot) may be able to grow other varieties–some success had been had with ‘Tuscan Blue’.I love one of the tips one of my customers gave me about using rosemary: she sprinkles the flowers on her family’s breakfast eggs–beautiful and delicious.But I’ll end with what everyone seems to agree on: that as a Mediterranean plant, rosemary likes it sunny and dry – which means great drainage, something that pots usually do a good job of providing. .
The Best Cold Hardy Rosemary Varieties
As the Mediterranean is the source of so much goodness on our dinner tables, it’s hardly a surprise that the region is also home to rosemary (Salvia rosmarinus), the pungent member of the mint family that adds the perfect flavor to many dishes.While US gardeners who live in climates similar to that of the Mediterranean – one that’s warm and dry – are able to grow rosemary year-round, those in more northern climes may fear they are less fortunate.Mother Nature has gifted our northern friends with a number of rosemary varieties that can withstand the chill and still reward with garden interest and palate pleasure.And while there are no varieties that are rated to consistently withstand the brutal chills of -10°F to -20°F temperatures that can occur in Zone 5 and below, with planning and preparation, gardeners in Zones 5, 6, and 7 have fairly solid odds of overwintering their plants.Before you even install your rosemary plants in the garden, give the process some consideration.The easiest way to ensure it survives the winter is to plant rosemary in a container, and overwinter it indoors.However, if your plant is already in the ground, and you’re thinking it might not make it through the winter chill, consider digging it up and replanting it in a container.Plan to do this in late August or early September, and why not prepare some grilled rosemary-garlic hamburgers from our sister site Foodal the evening you do the trimming, so you can make use of all those flavorful cuttings.Alcalde This variety was originally found growing in a northern New Mexico garden and was brought into cultivation by Charles Martin, an agronomist.Athens Blue Spire Discovered in 1998 in a crop sown from a packet of commercial rosemary seeds by a horticulture researcher at the University of Georgia, this variety is still making its way to widespread availability.Find a live ‘Hill’s Hardy’ rosemary plant in a four-inch pot at Hirt’s Gardens via Amazon.Choose a variety that is known to be cold hardy, and carefully place it where it will have the best chance against winter’s wrath. .
Planting, Growing, and Harvesting Rosemary Plants
Hailing from the shores of the Mediterranean Sea, rosemary does best in warm areas with fair humidity, where it can grow into a shrub several feet in height. .
Planting rosemary in-ground in Zone 7
Winter's here aren't terribly bad, although snow, albeit rare, is not out of the question and freezing temps are not at all uncommon.I have a neighbor right on the other side of my privacy fence that has a garden (planted in-ground), and I admired his rosemary bush one day.He said he just left it outside and although it seemed to go dormant during the winter, as soon as warm weather arrived, it perked right back up and did beautifully. .
A slow-growing, upright, bushy herb, rosemary often reaches 3 to 5 feet tall after several years of growth.They make excellent container plants, topiaries, or edgings for rock walls and terraces in the warmer areas of the lower South.Rosemary flowers vary from white to pink to blue, and the blooming time depends on the selection.The wall will absorb the sun's warmth and radiate heat at night, as well as shield the plant from north winds.If you live in a windy location, always choose a protected spot for your rosemary, because extreme cold in Zones 8 and 9 can kill the tops of this herb.Rosemary likes evenly moist soil but is susceptible to root rot if kept too wet.If you live in an area north of Zone 8, move rosemary to a protected location or bring it indoors for winter.Prostrate types are generally less cold hardy and should be grown in containers or hanging baskets that can be moved to a protected location.Strip fresh leaves from stems, chop, and add as an accent in soups, meats, stews, or vegetables.Work rosemary into bread dough, or mix it with wine or olive oil and garlic for a marinade.Rosemary can become a simple luxury when you drop a sprig into bathwater, add it to a bouquet, or wrap it around a napkin ring.Burn a bunch of rosemary branches over charcoal when grilling to enhance the flavor of foods. .
How to Protect Rosemary Plants in the Winter
Fortunately, there are measures you can take to protect your plants from the cold, and have them come back healthy and vigorous in spring.A big factor in determining if your rosemary will survive the winter outdoors is your USDA Plant Hardiness Zone.Then cover the whole plant with a mulching material such as straw, leaf mold, or wood chips.If you live in Zone 7 or below and your plants are growing in the ground outside, you’ll need to pot them up and take them indoors away from the cold.Carefully lift the plant and the root ball out of the ground, shake off some of the excess soil and place it in a large container.A lightly heated garage or hallway is a good option, as warm indoor air can cause the plant to dry out.Rosemary likes a bit of humidity, so gentle misting of the foliage can help keep the air around it moist.Make sure you don’t overwater, as rosemary hates sitting in wet soil.Once the temperatures start to warm up, you can move your pot outside during the day to gradually acclimate the plant to the outdoors. .