When to Plant Rosemary in Agate, North Dakota (58310)

Location

Agate, North Dakota

ZIP Code

58310

USDA Zone

Last Frost

Wednesday, May 20, 2026

📅 Your 2026 Planting Dates

Start Seeds Indoors

Wednesday, March 11, 2026

Transplant Outdoors

Wednesday, June 3, 2026

Based on last frost Wednesday, May 20, 2026 · Zone 3b

Pro tip: Start Rosemary seeds indoors 10 weeks before your last frost date, then transplant outdoors around Wednesday, June 3, 2026.

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🌿 Plant Details

Scientific Name Salvia rosmarinus

Days to Maturity 120 days

Mature Height 24-48"

Spread 24"

Type Shrub

Fruit Size N/A

☀️ Growing Requirements

☀️

Sun

Full Sun (6+ hours)

💧

Water

Low (drought tolerant)

↔️

Spacing

24" apart

🌱

Planting Depth

0.25" deep

Seeds typically germinate in 14-21 days

Ready to Plant Rosemary in Agate?

Get your seeds now so they're ready by Wednesday, March 11, 2026.

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🤝 Good Companions

BeanCabbageCarrotSage

🤝

Full Companion Planting Guide for Rosemary

See which plants help Rosemary thrive, which to keep away, and raised bed layout tips →

🛠️ Supplies You'll Need

🌱 Seed Starting Trays 🪴 Seed Starting Mix 💡 Grow Lights 🌡️ Heat Mat 🪵 Raised Garden Bed 🌍 Vegetable Garden Soil 🛠️ Hand Trowel Set 🚿 Watering Can

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Common Rosemary Varieties

Popular cultivars to look for at your local nursery or seed supplier.

Tuscan Blue

cultivar

Vigorous upright rosemary with large, intensely fragrant leaves — excellent for cooking.

Arp

cultivar

One of the most cold-hardy rosemaries, surviving to Zone 6 with protection.

Blue Spires

cultivar

Tall, upright variety with blue-toned flowers; fragrant and great for hedges.

Prostrate (Irene)

cultivar

Low-growing trailing rosemary that cascades over walls and containers beautifully.

🌾 Seed Saving Guide

🟡 Moderate

✅ Open-pollinated — seeds grow true to parent

When to Harvest Seed

Collect seeds from dried flower clusters in late summer after flowering.

Processing

Strip dried flower clusters, separate seeds from chaff. Surface sow — seeds need light to germinate.

Seed Viability

Up to 2 years when stored cool, dark, and dry.

Pro Tip

Rosemary seed germination rates are low (20–30%). Stem cuttings give far more reliable results.

🪴

Raised Bed Planting Guides

A 4×8 bed fits 8 plants of Rosemary. See plant counts, spacing grids, and companion pairings for every bed size →

Frequently Asked Questions

When should I plant Rosemary in Agate, North Dakota? +

In Agate (Zone 3b), start Rosemary seeds indoors around Wednesday, March 11, 2026 and transplant outdoors around Wednesday, June 3, 2026.

What is the last frost date for Agate, North Dakota? +

The average last spring frost date for Agate, North Dakota (ZIP 58310) is around Wednesday, May 20, 2026. This is based on NOAA climate normals for USDA Zone 3b.

How long does Rosemary take to grow? +

Rosemary typically matures in about 120 days from transplanting. In Agate, that means you can expect harvest around Wednesday, June 3, 2026 plus 120 days.

Should I start Rosemary indoors or direct sow in North Dakota? +

Rosemary should be started indoors 10 weeks before your last frost date. In Agate, that means starting around Wednesday, March 11, 2026.

📚 More Rosemary Planting Guides

🗺️

Rosemary in North Dakota

Zone-by-zone breakdown · Full state guide

→ 🌡️

Zone 3b Rosemary Guide

All cities in your zone · Avg dates

→

Other Plants for Agate

Blackberry Blueberry Raspberry Strawberry Basil Chamomile Chives Cilantro Dill Lavender Lemon Balm Marjoram Mint Oregano Parsley Sage Tarragon Thyme Acorn Squash Artichoke Arugula Asparagus Beefsteak Tomato Beet Bell Pepper Bok Choy Broccoli Brussels Sprout Butternut Squash Cabbage Cantaloupe Carrot Cauliflower Cayenne Pepper Celery Cherry Tomato Chili Pepper Collard Green Common Bean Cucumber Eggplant Endive Fennel Garlic Grape Tomato Green Bean Habanero Pepper Head Lettuce Heirloom Tomato Honeydew Melon Jalapeño Pepper Kale Kohlrabi Leaf Lettuce Leek Lima Bean Mustard Okra Onion Parsnip Pea Poblano Pepper Pole Pea Potato Pumpkin Radicchio Radish Rhubarb Roma Tomato Rutabaga Serrano Pepper Shallot Snap Pea Snow Pea Spaghetti Squash Spinach Squash Sweet Corn Sweet Potato Swiss Chard Tomato Turnip Watermelon Zucchini Sunflower Marigold Zinnia Nasturtium Cosmos Echinacea (Coneflower) Petunia Black-eyed Susan Apple Tree Pear Tree Peach Tree Plum Tree Sweet Cherry Tree Lemon Tree Borage Lemongrass Ginger Stevia Tomatillo Edamame Fava Bean Mâche Mizuna Sorrel Shishito Pepper Banana Pepper Watermelon Radish Napa Cabbage Popcorn Broccoli Raab Catnip Valerian Lemon Verbena Bee Balm Anise Lovage Chervil Summer Savory Dahlia Snapdragon Pansy Sweet Pea Morning Glory Hollyhock Larkspur Bachelor Button Columbine Impatiens Salvia (Annual) Sweet Alyssum Celosia Lupine Verbena Elderberry Grape Vine Red Currant Gooseberry Serviceberry Fig Tree Avocado Tree Persimmon Tree Olive Tree

Growing Rosemary in Zone 3b

Rosemary (Salvia rosmarinus) is a popular garden vegetable. In Agate, North Dakota, which is in USDA Hardiness Zone 3b, you should start seeds indoors around Wednesday, March 11, 2026.

Your average last frost date is Wednesday, May 20, 2026. Plan to transplant your Rosemary seedlings outdoors around Wednesday, June 3, 2026, about 2 weeks after your last frost date.