Rosemary

Quick Reference:

 

Type of Harvest: Continuous harvest

Transplant/Direct Sow: Direct sow or transplant

When to Plant: Start seeds indoors 2-3 months before the average last frost date for spring. Transplant outdoors when hardened off and all danger of frost has passed. Once established, rosemary will handle some frost. 

Days to Germinate: 15-30 days

Days to Maturity: 180 days

Planting Depth: 1/4” deep

Germination Temp: 70°F

Seed Spacing: Plant 3” apart. Thin to 18-24” apart.

Row Spacing: 12"-18 apart for annual plants - 24" apart for perennials.

Light: Full sun

Soil pH: 6.0-7.0 pH

Water:  Water when the top three inches of the soil are dry. Rosemary is a Mediterranean plant with long dry summers. It likes to suffer a little during the warmer months, but regular water will help it thrive. 

Soil Temperature: Minimum 70°F. These are heat loving plants.

Fertilizer: 12-12-17 N-P-K ratio

Rotation: Not needed for the rosemary; if planted in a container amend the soil once per year. If planted in the ground, top dress with fertilizer periodically.

 

Planting and Care:

Harvest Type

Rosemary is a continuously harvested herb. In colder climates bring it indoors in winter or protect in place with mulch and cover. 

Transplant / Direct Sow

Direct sow or start seeds indoors 2-3 months before the last frost date. Rosemary seeds can be difficult to germinate but allow them time. Seeds germatate best when the temperature is 70°F. Use a heat mat as needed. 

Sun: 

Full Sun

When to Plant:

Transplant or direct sow seeds when the soil temperature is 70°F.

Days to germinate

It takes most broccoli cultivars 15-30 days to sprout.

Days to maturity

It takes about 180 days for rosemary plants to reach maturity. You can sometimes nip the tips of the plants around 120 days but only if the plant is healthy and strong. 

Planting Depth

Plant seeds 1/4" deep.

Germination Temperature Range

Germination is best when the soil is 70°F.

Spacing Between Plants

Plant seeds 3" apart and thin to 18-24". If the plant is grown as an annual 12-18" between plants is plenty of room. If grown as a perennial, 18-24" between plants is ideal. 

TIP: Plant rosemary plants at the head of vegetable rows as it helps to naturally control pest insects. 

Companion Plants

Interplant rosemary and brassica to deter brassica pests. 

Growing conditions

Rosemary likes the weather to be warm and sunny. It can handle hot weather and it is considered a drought-tolerant plant. However, the oils and aroma of rosemary will be much livelier with regular water. Rosemary plants will tolerate poor soil, but a sandy soild that is well-draining with compost and nutrients is ideal. 

Rotation

Rotating rosemary is not necessary. If grown in containers be sure to amend the soil each year. 

Anticipated yields

Plan your garden yield at 1-2 rosemary plants per person. For a family of four 2-4 rosemary plants should be sufficient. As perennial plants, never harvest more than 1/3 of the plant at any given time.