When to Plant Rosemary in Cable, Wisconsin (54821)

Location

Cable, Wisconsin

ZIP Code

54821

USDA Zone

Last Frost

Friday, May 15, 2026

📅 Your 2026 Planting Dates

Start Seeds Indoors

Friday, March 6, 2026

Transplant Outdoors

Friday, May 29, 2026

Based on last frost Friday, May 15, 2026 · Zone 4a

Pro tip: Start Rosemary seeds indoors 10 weeks before your last frost date, then transplant outdoors around Friday, May 29, 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 Cable?

Get your seeds now so they're ready by Friday, March 6, 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 Cable, Wisconsin? +

In Cable (Zone 4a), start Rosemary seeds indoors around Friday, March 6, 2026 and transplant outdoors around Friday, May 29, 2026.

What is the last frost date for Cable, Wisconsin? +

The average last spring frost date for Cable, Wisconsin (ZIP 54821) is around Friday, May 15, 2026. This is based on NOAA climate normals for USDA Zone 4a.

How long does Rosemary take to grow? +

Rosemary typically matures in about 120 days from transplanting. In Cable, that means you can expect harvest around Friday, May 29, 2026 plus 120 days.

Should I start Rosemary indoors or direct sow in Wisconsin? +

Rosemary should be started indoors 10 weeks before your last frost date. In Cable, that means starting around Friday, March 6, 2026.

📚 More Rosemary Planting Guides

🗺️

Rosemary in Wisconsin

Zone-by-zone breakdown · Full state guide

→ 🌡️

Zone 4a Rosemary Guide

All cities in your zone · Avg dates

→

Other Plants for Cable

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 4a

Rosemary (Salvia rosmarinus) is a popular garden vegetable. In Cable, Wisconsin, which is in USDA Hardiness Zone 4a, you should start seeds indoors around Friday, March 6, 2026.

Your average last frost date is Friday, May 15, 2026. Plan to transplant your Rosemary seedlings outdoors around Friday, May 29, 2026, about 2 weeks after your last frost date.