How to Successfully Grow Rosemary from Seeds Indoors: A Step-by-Step Guide

Rosemary is a classic herb prized for its pine-like fragrance and robust flavor that enhances many dishes. While rosemary can be purchased at the grocery store, growing your own rosemary from seeds allows you to enjoy fresh rosemary whenever you need it. Plus, homegrown rosemary likely has better flavor and quality than store-bought.

Rosemary can be grown from seeds indoors to produce plants ready for your garden With proper care and favorable conditions, rosemary will grow from seed to an established plant in about a year Follow this complete guide to successfully grow rosemary from seeds indoors.

When to Start Rosemary Seeds Indoors

Rosemary seeds require plenty of time to grow before moving plants outside For best results

• Start seeds 12-14 weeks before your last expected spring frost.

• Allow at least 8 weeks for good germination and seedling growth indoors.

• Then transplant outdoors after all danger of frost has passed.

This timeline allows young rosemary plants a full growing season to become well established by fall. Adjust timing as needed for your climate and growing zone.

Gather Your Seed Starting Supplies

You’ll need the following supplies to start rosemary seeds indoors:

• Small containers or cell packs – Use individual 3-4 inch pots or multi-cell trays.

• Seed starting mix – Use a lightweight, nutrient-rich mix.

• Plastic dome or wrap – To cover seeds and retain moisture.

• Grow lights – Full spectrum fluorescent or LED lights.

• Heating mat – To provide 65°F to 70°F soil warmth.

• Labels – To mark each variety of rosemary seed.

The right tools and environment are key for robust seedlings ready to transplant into the garden successfully.

How to Plant Rosemary Seeds

Follow these simple steps for planting rosemary seeds:

1. Fill containers with moistened seed starting mix. Smooth and level the surface.

2. Place 1-2 rosemary seeds on the soil surface of each container, spaced 1 inch apart.

3. Gently cover seeds with a thin sprinkling of mix, about 1/8 inch deep.

4. Water gently to moisten the soil without displacing seeds.

5. Add plastic domes or wrap to seal in moisture.

6. Place containers on a heating mat set to 65°F to 70°F.

7. Provide 14-16 hours per day of grow light exposure, with lights 4-6 inches above.

8. Maintain consistent warmth and moisture until seedlings sprout.

9. Remove domes once the first seedlings appear. Thin to one seedling per cell or pot.

Follow proper care and rosemary will germinate in 14-21 days indoors.

Caring for Rosemary Seedlings

Proper care once sprouted is vital for growing healthy, robust seedlings:

• Maintain warm soil temperatures, around 70°F during the day.

• Keep seedlings moist but avoid saturation. Allow soil to partially dry out between waterings.

• Provide bright light for 12-16 hours daily. Supplement with grow lights.

• Wait to fertilize until true leaves emerge. Use a diluted liquid fertilizer.

• Gently circulate air to strengthen seedlings but avoid drafts.

• Watch for fungal issues like damping off disease and treat promptly.

• Transplant into larger individual containers once roots fill the cell packs.

With attentive care, rosemary seedlings will grow rapidly and gain size and strength. They will be ready for the outdoor garden in about 8-10 weeks.

Acclimating and Transplanting Rosemary Outdoors

Before moving rosemary seedlings outside, it’s important to properly acclimate them to prevent transplant shock:

• Begin hardening off seedlings 7-10 days before transplanting.

• Set containers outdoors in partial shade during the day, bringing in at night.

• Slowly increase their sun and wind exposure over the hardening off period.

• Plant outdoors only after the last expected spring frost date has passed.

• Choose a site with full sun and very well-draining soil. Amend if needed.

• Space transplants 18-24 inches apart in the garden bed or container.

• Water thoroughly after transplanting and provide shade for a few days.

Proper hardening off and transplanting allows young rosemary plants to continue thriving outdoors. Provide attentive care while plants establish.

Ongoing Care for Seeded Rosemary

To keep your homegrown rosemary healthy and productive:

• Water only when the top inch of soil is dry. Avoid overwatering.

• Apply a slow-release granular fertilizer or monthly feeding with fish emulsion.

• Prune plants in early spring to shape and remove dead growth.

• Watch for common pests like spider mites, aphids, and scales. Use organic treatments if needed.

• Cover plants or bring containers indoors before frost in fall. Rosemary is not cold hardy.

-Harvest rosemary often to encourage bushy new growth. Use fresh or air dry leaves.

With proper ongoing care, rosemary started from seeds will continue maturing into an abundant herb crop this season and for years to come.

Tips for Success Growing Rosemary from Seed

Here are some helpful tips to remember:

• Soak seeds in water overnight or give them a cold stratification treatment before planting to increase germination.

• Always use fresh seed starting mix and sterile containers to prevent damping off disease.

• Lift domes daily to allow ventilation and prevent mold or rot diseases.

• Ensure seedlings receive enough light. Supplement with grow lights if needed.

• Let the soil dry out between waterings. Overwatering is the most common cause of failure.

• Transplant seedlings before they become root bound or leggy from lack of light.

• Introduce seedlings slowly to the outdoors over 7-10 days during hardening off.

• Pinch back tips of young plants to encourage bushy growth after transplanting.

With the right planning and care, growing rosemary from seeds can be very rewarding. In as little as 12-14 weeks, you can grow a lush crop of rosemary ready for harvest and enjoyment all season long.