When to Plant Watermelon in Honolulu, Hawaii (96801)
Location
Honolulu, Hawaii
ZIP Code
96801
USDA Zone
12b
Last Frost
Friday, January 1, 2027
📅 Planting Calendar
Start Seeds Indoors Friday, December 4, 2026
Transplant Outdoors Friday, January 15, 2027
Pro Tip: Start Watermelon seeds indoors 4 weeks before your last frost date for best results.
🌿 Plant Details
Scientific Name Citrullus lanatus
Days to Maturity 80 days
Mature Height 12-24"
Spread 72"
Type Vine
Fruit Size Large (10-30 lbs)
☀️ Growing Requirements
☀️
Sun
Full Sun (8+ hours)
💧
Water
Regular (1-2 inches/week)
↔️
Spacing
72" apart
🌱
Planting Depth
1" deep
Seeds typically germinate in 4-12 days
🤝 Good Companions
CornSunflowerMarigold
⚠️ Avoid Planting Near
Potato
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 Brussel 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 Zucchini
Growing Watermelon in Zone 12b
Watermelon (Citrullus lanatus) is a popular garden vegetable. In Honolulu, Hawaii, which is in USDA Hardiness Zone 12b, you should start seeds indoors around Friday, December 4, 2026.
Your average last frost date is Friday, January 1, 2027. Plan to transplant your Watermelon seedlings outdoors around Friday, January 15, 2027, about 2 weeks after your last frost date.