When to Plant Tomatoes in Honolulu County, HI
Tomatoes are the most popular home garden crop, available in thousands of varieties from tiny cherries to massive beefsteaks. They are warm-season plants needing full sun.
Honolulu County, Hawaii is in USDA Zone 11b. The average last spring frost is January 1 and the first fall frost is December 31, giving you a growing season of approximately 364 days.
At an elevation of 235 feet, Honolulu County receives approximately 44.3 inches of rainfall annually with predominantly silty clay soil. Summer highs average 88°F, providing good warmth for Tomatoes during the growing season. Clay soil retains moisture well for Tomatoes, but amend with compost to improve drainage and prevent root rot.
Honolulu County Soil Profile
Soil Type
Silty Clay
Soil pH
5.7-6.4
Drainage
Well Drained
Plant Planting Risk Windows
Percentages indicate frost risk at transplant. The 70% safe window means there is a 30% chance of frost after transplant — suitable for cold-hardy crops or gardeners with frost protection. The 90% safe window is best for tender plants.
Soil Compatibility in Honolulu County
How your county's soil matches Tomatoes's growing requirements.
Soil pH
Your soil pH (5.7–6.4) overlaps with Tomatoes's range (6.0–7.0), though not a perfect match.
Soil Texture
Your silty clay soil in Honolulu County is workable for Tomatoes. Add compost annually to improve structure.
Organic Matter
Organic matter is moderate (3.6%). Annual compost additions will help Tomatoes.
How to Plant Tomatoes
How Much Tomatoes to Grow
For a family of 4, plant approximately 12 tomatoes plants in about 72 sq ft. In Honolulu County's 364-day season, you'll have plenty of time for a full harvest. Plan your garden layout →
Plant Water Budget
Water stress score is 6/10 — consider drought-tolerant varieties and mulching
Monthly Watering Guide for Tomatoes
Tomatoes needs approximately 1.2 inches of water per week (5.2" per month). Here's how your county's rainfall compares month by month.
| Month | Tomatoes Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | 5.2" | 6.4" | 0" | ✅ Rainfall sufficient |
| Feb | 5.2" | 4.7" | 0.5" | 💧 Light watering |
| Mar | 5.2" | 6.2" | 0" | ✅ Rainfall sufficient |
| Apr | 5.2" | 3.9" | 1.3" | 💧 Light watering |
| May | 5.2" | 2.5" | 2.7" | 🚿 Regular watering |
| Jun | 5.2" | 1.3" | 3.9" | 🚿 Regular watering |
| Jul | 5.2" | 0.9" | 4.3" | 🚿 Regular watering |
| Aug | 5.2" | 1.3" | 3.9" | 🚿 Regular watering |
| Sep | 5.2" | 2.2" | 3" | 🚿 Regular watering |
| Oct | 5.2" | 4.4" | 0.8" | 💧 Light watering |
| Nov | 5.2" | 4.2" | 1" | 💧 Light watering |
| Dec | 5.2" | 6.2" | 0" | ✅ Rainfall sufficient |
Water needs are for active growing months only (Jan–Dec in Honolulu County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Tomatoes Heat Requirements (GDD)
What are Growing Degree Days (GDD)?
Growing Degree Days measure the total warmth your plants receive during the growing season. Think of it as a "heat bank" — every day above 50°F deposits warmth that helps your plants grow.
Each plant needs a certain amount of accumulated heat to mature. If your county provides more GDD than the plant needs, it's a great fit. If it's close, you may want to choose faster-maturing varieties or start seeds indoors to get a head start.
Tomatoes Planting Timeline — Honolulu County, HI
Tomatoes Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | November 20 | Nov 20 – Dec 4 |
| Transplant Outdoors | January 8 | Jan 8 – Jan 22 |
| Direct Sow | January 1 | Jan 1 – Jan 22 |
| Harvest | March 12 | Mar 12 – May 21 |
Plant 0.5" deep · 24" apart · Rows 36" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | Transplant Outdoors Direct Sow |
| February | — |
| March | Harvest |
| April | Harvest |
| May | Harvest |
| June | — |
| July | — |
| August | — |
| September | — |
| October | — |
| November | Start Indoors |
| December | Start Indoors |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
1.2"/week · 2-3 times/week
📅 Days to Maturity
60–85 days
🧪 Soil pH
Needs 6–7 · Your soil: acceptable
🗺️ USDA Zone
Zone 11b
📆 Growing Season
364 days in Honolulu County
Growing Tips for Tomatoes in Honolulu County
With Honolulu County's clay soil (36% clay), work in 3-4 inches of compost before planting Tomatoes. Avoid tilling when soil is wet to prevent compaction.
Common pests for Tomatoes in this region include tomato hornworm and aphids. Use row covers early in the season and inspect plants weekly.
General growing tips
Start seeds indoors 6-8 weeks before last frost. Bury transplants deep to encourage rooting along the stem. Provide consistent moisture to prevent blossom end rot and cracking.
Recommended Tomatoes Varieties for Honolulu County
Your long season supports large indeterminate heirloom types
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Isolate 25 ft between varieties for purity. Use open-pollinated varieties for true-to-type seeds.
Tomatoes in Other Locations
Frequently Asked Questions
When should I plant Tomatoes in Honolulu County, HI?
Honolulu County is in Zone 11b with an average last frost of January 1. Plan your Tomatoes planting based on this frost date — see the calendar above for exact timing.
What planting zone is Honolulu County, HI?
Honolulu County, Hawaii is in USDA Hardiness Zone 11b. The average last spring frost is January 1 and first fall frost is December 31.
Plan Your Garden with Confidence
Get our free Garden Planner — designed to help Honolulu County gardeners in Zone 11b organize planting dates, track what's growing, and never miss a planting window.
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