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When to plant Kabocha in Seffner, FL

Kabocha planted in Seffner between January 25 and February 15 matures in 100 days — well before the December 20 first frost.

When to Plant Kabocha in Seffner, FL

Hillsborough County, Florida Zone 10a June

June in Hillsborough County, Florida — your action list

Each item below is timed to Hillsborough County, Florida's frost dates and soil temperatures. Skip nothing, stress about nothing.

Avg. last frost January 25
Avg. first frost December 20
Soil temp (4") 88°F
Watering Low
Pest pressure High
Daylight 13.8 hrs
  1. Survive, don't thrive

    June-August is endurance gardening. Keep okra, peppers, sweet potatoes, and southern peas alive. Harvest everything daily before the heat damages produce on the vine.

  2. Start fall tomato seeds indoors

    Yes, indoors — under lights or in AC. They'll be ready to transplant in August when temperatures briefly moderate.

  3. Add compost to empty beds

    Empty beds get a thick layer of compost + mulch to suppress weeds and feed the soil for fall planting.

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Kabocha is a Japanese winter squash with an exceptionally sweet, dense, chestnut-like flesh and dark green skin. It is a favorite in Asian cuisine for its rich, dry texture.

Seffner, Florida is in USDA Zone 10a. The average last spring frost is January 25 and the first fall frost is December 20, giving you a growing season of approximately 329 days.

At an elevation of 63 feet, Hillsborough County receives approximately 54.4 inches of rainfall annually with predominantly sand soil. Summer highs average 98°F, so Kabocha may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Kabocha will need more frequent watering and organic matter to retain nutrients. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Kabocha root diseases.

Seffner, FL (Zone 10a) Year-round
329 days
Last Spring Frost January 25
329 growing days
First Fall Frost December 20

Seffner Soil Profile

Soil Type

Sand

Soil pH

4.9-5.9

Drainage

Well Drained

Kabocha Planting Risk Windows

Early Start (70% safe) ✓ Fits season (200 days to spare)
Start indoors: Dec 20 Transplant: Jan 24 🍅 Harvest: Apr 25 – May 23
Recommended (50%) ✓ Fits season (203 days to spare)
Start indoors: Dec 28 Transplant: Feb 1 🍅 Harvest: May 3 – May 31
Safe Start (90%) ✓ Fits season (179 days to spare)
Start indoors: Jan 26 Transplant: Mar 2 🍅 Harvest: Jun 1 – Jun 29

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 Seffner

How your county's soil matches Kabocha's growing requirements.

Soil pH

Your soil pH (4.9–5.9) is more acidic than Kabocha prefers (6.0–7.5). Add garden lime to raise pH.

Soil Texture

Sandy soil in Hillsborough County warms quickly in spring but drains fast. Kabocha will need more frequent watering and regular compost additions to retain nutrients.

Drainage

Drainage is adequate for Kabocha.

Organic Matter

Organic matter is low (1.5%). Add 2-3 inches of compost before planting Kabocha.

How to Plant Kabocha

1"
Planting Depth
30"
Between Plants
42"
Between Rows

Kabocha Water Budget

Plant needs
1.0″/week
Rainfall provides
0.7″/week
You supply
0.7″/week
Watering frequency 2-3 times/week
Season total 2,142 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Kabocha

Kabocha needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Kabocha Needs Rainfall You Supplement Action
Jan 4.3" 2.3" 2" 💧 Light watering
Feb 4.3" 2.7" 1.6" 💧 Light watering
Mar 4.3" 2.9" 1.4" 💧 Light watering
Apr 4.3" 2.1" 2.2" 🚿 Regular watering
May 4.3" 3.8" 0.5" 💧 Light watering
Jun 4.3" 8.1" 0" ✅ Rainfall sufficient
Jul 4.3" 8" 0" ✅ Rainfall sufficient
Aug 4.3" 8" 0" ✅ Rainfall sufficient
Sep 4.3" 7.7" 0" ✅ Rainfall sufficient
Oct 4.3" 4.5" 0" ✅ Rainfall sufficient
Nov 4.3" 2" 2.3" 🚿 Regular watering
Dec 4.3" 2.4" 1.9" 💧 Light watering

Water needs are for active growing months only (Jan–Dec in Hillsborough County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Kabocha 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.

Kabocha needs ~2,174 GDD — county provides 7,755 GDD Excellent fit

Kabocha Planting Timeline — Seffner, FL

Kabocha Planting Calendar

Activity When Date Range
Start Indoors December 28 Dec 28 – Jan 11
Transplant Outdoors February 1 Feb 1 – Feb 15
Direct Sow January 25 Jan 25 – Feb 15
Harvest May 3 May 3 – May 31

Plant 1" deep · 30" apart · Rows 42" apart

Month-by-Month Timeline

MonthActivities
January Start Indoors Direct Sow
February Transplant Outdoors Direct Sow
March
April
May Harvest
June
July
August
September
October
November
December Start Indoors

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · 2-3 times/week

📅 Days to Maturity

85–100 days

🧪 Soil pH

Needs 6–7.5 · Your soil: too_acidic

🗺️ USDA Zone

Zone 10a

📆 Growing Season

329 days in Hillsborough County

Growing Tips for Kabocha in Seffner

Direct sow Kabocha outdoors after January 25 in Hillsborough County when soil has warmed and frost danger has passed.

Sandy soil in Hillsborough County dries quickly — mulch Kabocha with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.

With summer highs reaching 98°F in Hillsborough County, provide afternoon shade for Kabocha and water deeply in the morning.

Common pests for Kabocha in this region include squash vine borer and cucumber beetles. Use row covers early in the season and inspect plants weekly.

General growing tips

Direct sow after frost or start indoors. Harvest when the skin is hard and dull. The stem should be dry and corky. Stores well for 3-4 months in a cool, dry place.

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes

Check more plant combinations with our Companion Planting Checker →

When should I plant Kabocha in Seffner, FL?

In Seffner, FL, plant Kabocha after the last frost (around January 25) and before the first frost (around December 20). Best results when soil holds above 50°F.

What growing zone is Seffner, FL for Kabocha?

Seffner sits in USDA Zone 10a. Kabocha grows reliably in zones 3a through 11b, so it's a good fit here.

Can Kabocha grow in Seffner's climate?

Yes — Kabocha grows well in Seffner's temperate climate. Seffner averages a 330-day frost-free season, with last frost around January 25 and first frost around December 20.

🌱

Your Hillsborough County Garden Planner — Free

A 22-page printable planner built for Hillsborough County (Zone 10a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Hillsborough County, FL. Local conditions may vary. Last updated: June 2026.