When to Plant Radish in Honolulu, Hawaii (96821)

Location

Honolulu, Hawaii

ZIP Code

96821

USDA Zone

12b

Last Frost

Thursday, January 1, 2026

📅 Planting Calendar

Direct Sow Outdoors Thursday, November 20, 2025

Pro Tip: Sow Radish directly outdoors 6 weeks before your last frost date.

🌿 Plant Details

Scientific Name Rhaphanus sativus

Days to Maturity 25 days

Mature Height 6-12"

Spread 3"

Type Root

Fruit Size Small (1-2 inches)

☀️ Growing Requirements

☀️

Sun

Full Sun to Partial Shade

💧

Water

Regular (keep moist)

↔️

Spacing

2" apart

🌱

Planting Depth

0.5" deep

Seeds typically germinate in 3-7 days

Ready to Plant Radish in Honolulu?

Get your seeds now so they're ready by Thursday, November 20, 2025.

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🤝 Good Companions

CarrotLettucePeaCucumberSpinach

⚠️ Avoid Planting Near

Hyssop

Other Plants for Honolulu

Blackberry Blueberry Raspberry Strawberry Basil Chamomile Chives Cilantro Dill Lavender Lemon Balm Marjoram Mint Oregano Parsley Rosemary 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 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 Radish in Zone 12b

Radish (Rhaphanus sativus) is a popular garden vegetable. In Honolulu, Hawaii, which is in USDA Hardiness Zone 12b, you should direct sow seeds around Thursday, November 20, 2025.

Your average last frost date is Thursday, January 1, 2026. Radish grows well when direct sown, as it doesn't transplant well or germinates quickly outdoors.