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Growing rosemary from seed in the garden

Growing Rosemary from Seed (a.k.a. Sprouting Demon Seedlings)

Rosemary will always be associated with warding off the terrors of the night, but sometimes, not everything is as it may seem.

"Want to make friends with your neighbors? Grow rosemary in your front yard," one of our customers, Melanie, told us. "I had a couple really nice rosemary bushes along the sidewalk, and at least once a week, in the dead of night, someone would come sneaking over with some pruners, clip off a sprig or two, and then dash off into the shadows." She lived in Portland, Oregon at the time and according to her, so did a LOT of rosemary shrubs. But she was the only one on her block who grew it within reach of passersby.

"I eventually put a sign out in my garden welcoming people on my street to harvest it as needed, and the next thing I knew, I was getting loaves of rosemary olive bread on my porch, with notes from a neighbor nobody had met in more than a decade."

Rosmarinus officinalis is, of course, much more than Boo Radley bait. Its an essential plant for any herb garden and rosemary starts are a great way for hobbyists or herb farmers to make some money on the side.

Rosemary's Origins, Traditions, and Herbal Uses

Ros maris is Latin for "dew of the sea", and as a native of Mediterranean coastlines, a landscaped covered by Rosmarinus officinalis would indeed seem like a deep green ocean dotted with pale blue droplets when it's in bloom.

In another legend, the plant earned the name "Rose of Mary" in honor of a mother who fled Egypt and King Herod; she and her baby took shelter under a rosemary bush to hide from the soldiers tasked with executing all the infants in the land.

Medieval hippies used rosemary incense to keep "bad vibes" at bay, and rosemary was also used during the Plagues to ward off disease. Everyone would agree that catching bubonic plague would be, indeed, a major bummer, man.

When flea-infested rats weren't wreaking havoc on Europe, rosemary was kept under pillows as a talisman against nightmares.

Merchants hung rosemary sprigs in their shops and businesses to encourage prosperity, and "Hungary Water", made with rosemary, rose to fame when Queen Elizabeth of Hungary supposedly cured her arthritis after drinking it.

As much as it's associated with horrible moments in history and lore, rosemary has a rich heritage as an herbal remedy, and contemporary studies have found that the most active chemical components in rosemary are legitimately beneficial for the following:

  • Slows down hair loss
  • Reduces anxiety (probably about going bald)
  • Anti-inflammatory
  • Antioxidant
  • Improves brain function and memory
  • Improves Acne and oily skin
  • Cures boredom from bland food

How to Grow Rosemary

Rosemary grows outdoors as a perennial evergreen shrub in zones 7 or above. In zone 6, it may do very well... or it may not, given varying microclimates within each zone. In colder regions, where it should be treated as a tender perennial, rosemary is best grown as a container plant, so that you can bring it indoors during heavy frosts and low temperatures.

Plant Description

Believe it or not, rosemary is a member of the Lamiaceae (mint) family, though it hardly resembles its cousins.

Plant size: Rosemary can grow 4 to 6 feet tall and wide under optimal conditions but responds well to trimming and shaping.

Plant Shape and Growing Habits: Rosmarinus officinalis has an upright growing habit, though some varieties tend to have cascading or ground-hugging, spreading tendencies.

Leaf and Branch Description: Rosemary has flat, needle-shaped leaves, medium to dark green on the top and pale green, silver grey or even white underneath. Its leaves are about 1" long, and begin growing rosemary in sprigs about 1/4 from the bottom of each branch in a "bottle-brush" fashion. New leaf buds emerge from branch tips.

Rosemary branches are woody, with scaly bark. As the plant matures, its base often becomes twisted and gnarled, resembling that of a bonsai. In fact, rosemary is popular among bonsai gardeners, who are also masters at cultivating outdoor plants in indoor environments.

Flowers: Tiny, two-lipped rosemary blooms resemble lily flowers. They're usually pale blue or white, but can be pink or lavender. Rosemary usually blooms late spring and well into fall.

Aroma: Rosemary has a smoky, piney, camphorous fragrance when its leaves are crushed.

Where Rosemary Grows Best

We strongly recommend starting Rosmarinus officinalis indoors. It's a slow-germinating, slow-growing plant, so when you're planning the perfect permanent spot for your rosemary starts, think ahead. By the time your rosemary really starts growing, your existing garden plants may have matured; imagine how everything will look one or even two seasons from now. Growing rosemary from seed is a bit of an investment.

You'll also want to plant more seeds than you think you'll need because even with the freshest rosemary seeds, germination rates can be as low as 30%.

Soil Conditions: Rosemary does best with compost-rich, well-draining soil.

pH: 6 to 7.

Sunlight: Plant Rosmarinus officinalis in full sun. When potted, it will tolerate partial shade better than soil-planted rosemary.

Water Requirements: Rosemary does best when the top few inches of soil is allowed to dry out slightly. Container plants should be watered from the bottom, by placing pots (or starts) in a shallow tray. Water just enough for container plants to take up the moisture within an hour.

Rosemary prefers a bit of humidity, so it does well near grassy or well-mulched areas as long as it isn't being overwatered.

Mulching: Don't allow mulch to pile up against the base of your rosemary plants.

Companions: Brassicas and beans do very well near rosemary, which is believed to fend off cabbage moths, cabbage flies, and bean beetles. Rosemary isn't recommended as a neighbor for carrots, pumpkins, or potatoes.

Starting Rosemary Seeds

Did we mention that rosemary seeds are slow to germinate? First, refer to our post about germination for advice on cold stratification, a technique you'll definitely want to employ for rosemary seeds.

We recommend starting your seeds indoors as early as six months before your last spring frost to give them their best start.

Prepare new or sterilized seedling pots or trays (we recommend the domed plastic mini-greenhouse kits) with a mix of equal parts peat moss and Perlite, or lightweight sterilized soil-free seedling mix.

  • Place pots or trays in a shallow tray for bottom-watering.
  • Set the heat mat at 70 to 80°F in a room consistently heated to 55 to 65°F.
  • Sprinkle 2 to 3 rosemary seeds on the top of the substrate. Don't cover!
  • Mist with a spray bottle on its finest setting. Don't let the substrate surface dry out.
  • Cover with a plastic dome or plastic sheeting.
  • Place under an indoor full-spectrum light (recommended).

Next, gather together your creepiest neighbors, and start chanting. Under optimal conditions, your seeds should germinate in 14 to 25 days.

Once your seedlings have emerged, remove the plastic and continue with intermittent light mistings, but your plants' main water source will be from below. Rosemary does appreciate humidity but watch for mold. Keep them under a light, providing 2" between the light source and the top of your plants.

Don't allow your seedlings to become root-bound! Take great care in transplanting them to larger pots so you don't disturb the roots.

Transplanting Rosemary Outdoors

Wait until your rosemary plants are at least 6 inches tall before transplanting them into your compost-amended garden soil. You'll want to be sure all chance of frost has passed.

Rosemary as a Houseplant

If you plan to keep your rosemary plants indoors, you'll need to provide your plants with the following:

  • Cool or cold temperatures (during the winter months);
  • Humidity; and
  • Seven or more hours of bright sunlight or artificial full-spectrum light; more in the growing months. Rosemary doesn't grow much in "winter-length" sunlight.

You can boost the humidity around your rosemary plants by setting them in a tray partially filled with gravel or decorative pebbles (or the baby teeth of demon children), with just enough water to avoid flooding the base of the pot. If you have several plants on one tray, add just enough water for them to take up the excess moisture. Or by simply use a second "soaking" tray to water your rosemary for about 20 minutes when the soil becomes dry.

It's best to err on the dry side; overwatering is the leading cause of death for potted rosemary plants.

Be sure to mist your rosemary once in a while to combat the dryness of climate-controlled home environments. You'll know when they're not getting enough humidity when their needle tips begin to turn brown.

Potted rosemary winters well in cold frames down to zone 5, especially when you surround their containers with damp peat moss or chopped straw, or if you keep the soil at the bottom of the cold frames moist.

Maintaining Your Rosemary Plants

Pests and Diseases: Root rot is the biggest issue with rosemary, and is easily avoided by allowing the soil around your plants to dry out between watering. Water deeply and intermittently, and allow for air circulation around the base of each plant.

Rosemary is also susceptible to powdery mildew, in part because both love warm and humid environments during the growing season. Try a foliar spray of one teaspoon of baking soda to one quart of water every few mistings.

As far as insects go, keep an eye out for spittlebugs, aphids, and whiteflies. Fortunately, rosemary attracts beneficial wasps (as well as honeybees) when it's in bloom.

Fertilizing: Rosemary appreciates regular applications of an all-purpose fertilizer for the most potent leaves, longest blooms, best growth, and overall health. If you don't want to cater to a princess plant, just fertilize newly-transplanted rosemary. Its needles should be a rich, deep green on their topsides, so if you see them becoming washed out, side dress with well-aged manure or break out the off-the-shelf stuff.

Trimming and Harvesting: Trim rosemary any time during the growing season to maintain its desired shape, but never cut back more than two-thirds of the entire plant. Damaging the woody base can kill your plant, leaving it open to disease and pests.

Pinch off new leaves from the tips of rosemary's branches for the most palatable texture and flavor. Cut rosemary stems and hang them upside-down to dry, and store them in a cool, dark, dry cupboard. Strip the stems by running them through your "pinched" fingers. Hardier rosemary stems make great kabob sticks for the barbecue!

Fresh or dried rosemary needles should always be stored whole to maintain their flavor and freshness, and chopped or ground up only as they're needed.

Cooking With Rosemary

Fresh, tender rosemary leaves are easier to cook with and don't stab the h*** out of your mouth when eaten, but both dried and fresh rosemary have the same flavor value. If you're lucky enough to live where it's an evergreen perennial, you can harvest from your plants year-round.

Rosemary's taste and aroma are both described as having the same attributes. Close your eyes and get a whiff of:

  • Pine
  • Camphor
  • Lemon
  • Campfire (pine) smoke
  • Tea

Rosemary is traditionally used to season rabbit, lamb, pork, beef and venison roasts, and does well with any kind of recipe or marinade using olive oil or animal fats.

A Few Basic Recipes for Rosemary

Rosemary Olive Bread: Imagine sitting on a Tuscan terrace, dipping a warm slice of rosemary olive bread into a dish of freshly-pressed virgin olive oil... Hey! Where are you going? Put down that day-old Wonder Bread and jug of Wesson Oil. Get off the stoop of your single-wide and start planting those rosemary seeds, because there's no substitute for the real thing.

Rosemary Pork Roast: As far as we're concerned, any cut of pork just sizzles with flavor when its enhanced with a touch of fresh rosemary.

Rosemary Garlic Grass-Fed Burgers: This is a quick-and-dirty method for sprucing up clean meat, but the author is wrong about "grass-fed". All cattle are fed on grass, and most are finished on feedlots where they're finished with grain. We recommend (because our Montana shepherdess friend's head will explode if we don't) looking for "grass-finished" meat. Always question labels, especially in our age of competitive-and "creative"—marketing.

Get The Freshest Rosemary Seeds from Seed Needs!

We could go on and on with our favorite rosemary recipes, but chances are, you're familiar with rosemary's culinary repertoire. Our primary goal is making sure you have the best start to your rosemary herb garden, so you can take things from there.

And your best start comes from the best seeds. We hope you'll contact us if you have questions about our products; we love getting to know our customers, sharing recipes, even swapping quotes from favorite classic horror movies!
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1 comment

  • Started rosemary and wondering how to plant them into a larger pot. They are somewhat “leggy”, the first set of leaves are at 1.5” from the top of the dirt. Do I plant them deeper?


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