How to Grow Rosemary

General Information

Botanical Name:

Salvia rosmarinus (formerly Rosmarinus officinalis)

Common Names:

Rosemary

Plant Family:

Lamiaceae

Type:

Perennial; Culinary; Medicinal; Aromatic; Warm Season to Mild Cool Season Grower depending on climate

Our Favorite Varieties:

Tuscan Blue, Spice Island, Blue Rain, Majorca Pink

Know Before You Grow

Growing Zones:

8–10 as a reliable perennial outdoors; colder areas often grow it in containers or protect it in winter.

Frost Hardy:

Light frost tolerance once established, but hard freezes can damage or kill it, especially in colder zones.

Heat Tolerant:

Yes, if drainage is excellent; Rosemary is drought tolerant once established and dislikes wet, humid, poorly drained conditions.

Stratification:

No

Rows, Beds, Containers:

Yes to all three. Containers are often the best choice where winters are too cold or soil stays too wet.

Starting from Seed

When:

Start indoors about 10–12 weeks before the last frost. Transplanting is recommended over direct sowing.

Soil:

Soil-less Seed-starting mix

Depth:

Surface sow and press in lightly, or cover only very lightly. Rosemary seed needs light for best germination.

Water:

Keep evenly moist, not soggy

Germination:

14–21 days

Up Pot:

Up pot or thin when plants have 4 true leaves.

Light:

14–16 hours under grow lights indoors; full sun outdoors. At least 5 hours in a bright south-facing window if grown inside.

Soil Temperature:

65°F–70°F

Heat Mat:

Helpful, especially in a cool room, but not required if conditions are warm enough for germination.

Harden Off:

Yes, 7–10 days before transplanting outdoors.

Row, Bed, Container Prep

Soil:

Very well-drained, sandy or loamy soil. Rosemary declines in wet, heavy soil.

pH:

About 6.0–7.0

Soil Depth or Pot Size:

At least 8–12 inches of workable soil; one plant does well in a roomy container, about 12 inches wide or larger. This pot size is a practical container recommendation based on rosemary’s shrub-like growth habit.

Trellis:

no

Fertilizer/Feed:

Feed lightly. Over-fertilizing can reduce flavor and encourage softer growth.

Compost:

Mix in a modest amount before planting, but do not make the soil too rich or water-holding.

Transplanting/Up Potting

When:

After frost danger has passed.

How:

Transplant gently, keeping the rootball intact and putting into a well-drained soil in full sun.

Depth:

Same depth it was growing before

Spacing:

18 to 36 inches apart

Mulch:

Light mulch only, and keep it away from the crown and stems

Water:

Water in well, then let the soil begin to dry slightly between waterings

Direct Sowing

When:

After danger of frost has passed and the soil is warming, but direct sowing is usually not the best method because rosemary is slow and uneven from seed.

Depth:

Surface sow and press in lightly, or cover only very lightly.

Spacing:

Sow thinly, then thin to 18–36 inches apart.

Water:

Keep seed zone evenly moist until germination, then reduce frequency and avoid soggy soil.

Light:

Full sun

# in Sq. Ft. Planting:

1 Rosemary plant per square foot.

Growing Care

Fertilizer/Feed:

Feed lightly if needed. Rosemary generally does better with leaner feeding than with rich, fast growth.

Days to Maturity:

About 90–180 days from seed for a usable young plant; much faster from cuttings or transplants.

Water:

Water regularly while establishing. Once established, let the soil dry somewhat between waterings. Deep-rooted perennial herbs like rosemary should be watered more deeply than shallow annual herbs.

Pruning/Harvesting:

Prune lightly to shape and harvest sprigs. Do not cut deep into old bare wood. Heavy pruning keeps plants active, but avoid heavy fall pruning before winter.

Mulching:

Use only a light mulch and keep it away from the crown

Pollination:

Not needed for leaf production. Flowers attract bees and other pollinators.

Companions & Antagonists

Plant Family:

Antagonists:

Sage

None, just avoid planting with other plants that need rich, constantly moist soil or shade. Rosemary dislikes those conditions.

Thyme

–

Lavender

–

Mediterranean herbs

–

Attracts & Repels

Attracts:

Repels:

Bees and other pollinators when flowering.

It’s strong smell confuses many pests, and deters others.

Pests & Disease

Pests:

Disease:

Aphids

Powdery Mildew

Mealybugs

Root Rot

Whiteflies

Botrytis

Spider Mites

–

Seed Saving

When:

After flowers dry and seed heads mature on the plant

Method:

Let seed heads dry fully, cut them, dry more if needed, then shake or rub out the seed and store it dry.

Harvest Time

When:

Once plants are established enough to spare growth; harvest lightly the first season and more freely after the plant fills out.

How:

Snip sprigs or tender tips; avoid cutting back hard into old woody stems.

What:

Leaves and tender stem tips

Storing:

Fresh short-term in the refrigerator, or dry thoroughly and store airtight away from light. Herbs can also be frozen.

Preservation Methods:

Drying, freezing, infused vinegars, herb blends, and safely made infused oils

Medicinal Uses:

Traditionally Used for:

Dyspepsia and mild spasmodic gastrointestinal complaints; minor muscular and articular pain; minor peripheral circulatory complaints. Historical sources also describe tonic, stimulant, carminative, headache, and memory-related folk use.

Forms:

Tea/infusion, tincture, extract, syrup, infused oil, essential oil, external washes and rubs

Dosage or Application:

Traditionally used internally as a tea made from rosemary leaf, with an EMA monograph listing a daily dose of 2–6 g of the herbal substance as tea for oral use. External traditional use includes rosemary oil preparations for minor muscular and articular discomfort.

NOTICE:

This information is based on historical/traditional fact. It is for educational purposes only. Lowe Bridges Farm will not be held liable for your use of this information. Your use of this information and the results thereof is your responsibility, and yours alone.

Culinary Uses:

Flavor Profile:

Savory, piney, resinous, peppery

Best Used In:

Meats, roasted vegetables, potatoes, breads, soups, stews, beans, marinades

Forms:

Fresh sprigs, fresh chopped leaves, dried leaf, crushed, powdered

As an Aromatic:

Used for:

Its strong, penetrating, resinous aroma is traditionally used for stimulation, mental clarity, cleansing blends, and circulation-focused aromatic use. Historical sources also mention memory-related folk use.

How:

Fresh or dried in bundles and sachets, or as a properly diluted aromatic preparation; essential oil is very concentrated and should be used sparingly.

Troubleshooting

Yellowing and decline:

Usually overwatering or poor drainage

Powdery Coating on Foliage:

Poor airflow and high humidity can lead to Powdery Mildew

Plant rots at base:

Wet soil or crown staying too damp

Leggy or weak growth:

Not enough sun or too much rich feeding.

Winter Damage:

Hard freezes or wet winter soil can kill plants, especially outside their best hardiness range.

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