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When to Plant Hubbard Squash in Baltimore City, MD

Baltimore City, Maryland Zone 8a May

Baltimore City, Maryland gardeners: here's your May plan

We've pulled the most time-sensitive tasks for Baltimore City, Maryland this May and put them front and centre. Tackle them in order.

Avg. last frost April 3
Avg. first frost November 6
Soil temp (4") 69°F
Watering Low
Pest pressure Moderate
Daylight 14.2 hrs
  1. Time to start hubbard squash inside

    Bottom-water once the first true leaves appear — it keeps stems dry and knocks back damping-off.

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Hubbard squash is a large, bumpy-skinned winter squash with dense, sweet, dry flesh ideal for baking and pies. The hard shell allows storage for 6 months or more.

Baltimore City, Maryland is in USDA Zone 8a. The average last spring frost is April 3 and the first fall frost is November 6, giving you a growing season of approximately 217 days.

At an elevation of 213 feet, Baltimore City receives approximately 48.7 inches of rainfall annually with predominantly silt loam soil. Summer highs average 94°F, providing good warmth for Hubbard Squash during the growing season.

Baltimore City, MD (Zone 8a) Long season
217 days
Last Spring Frost April 3
217 growing days
First Fall Frost November 6

Baltimore City Soil Profile

Soil Type

Silt Loam

Soil pH

5.5-6.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (64 days to spare)
Start indoors: Feb 28 Transplant: Apr 11 🍅 Harvest: Jul 25 – Aug 29
Recommended (50%) ✓ Fits season (63 days to spare)
Start indoors: Mar 6 Transplant: Apr 17 🍅 Harvest: Jul 31 – Sep 4
Safe Start (90%) ✓ Fits season (65 days to spare)
Start indoors: Mar 19 Transplant: Apr 30 🍅 Harvest: Aug 13 – Sep 17

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 Baltimore City

How your county's soil matches Hubbard Squash's growing requirements.

Soil pH

Your soil pH (5.5–6.8) overlaps with Hubbard Squash's range (6.0–7.0), though not a perfect match.

Soil Texture

The silt loam soil in Baltimore City is excellent for Hubbard Squash — good drainage, moisture retention, and nutrient holding capacity.

Drainage

Drainage is adequate for Hubbard Squash.

Organic Matter

Organic matter is moderate (3.0%). Annual compost additions will help Hubbard Squash.

How to Plant Hubbard Squash

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

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.9″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft

Monthly Watering Guide for Hubbard Squash

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

Month Hubbard Squash Needs Rainfall You Supplement Action
Jan 3.5" 0" ❄️ Dormant
Feb 2.8" 0" ❄️ Dormant
Mar 4.3" 0" ❄️ Dormant
Apr 4.3" 4.6" 0" ✅ Rainfall sufficient
May 4.3" 4.7" 0" ✅ Rainfall sufficient
Jun 4.3" 4.1" 0.2" 💧 Light watering
Jul 4.3" 4.6" 0" ✅ Rainfall sufficient
Aug 4.3" 4" 0.3" 💧 Light watering
Sep 4.3" 4.4" 0" ✅ Rainfall sufficient
Oct 4.3" 4" 0.3" 💧 Light watering
Nov 4.3" 4" 0.3" 💧 Light watering
Dec 3.8" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Nov in Baltimore City). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Hubbard Squash 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.

Hubbard Squash needs ~2,255 GDD — county provides 4,448 GDD Excellent fit

Hubbard Squash Planting Timeline — Baltimore City, MD

Hubbard Squash Planting Calendar

Activity When Date Range
Start Indoors March 6 Mar 6 – Mar 20
Transplant Outdoors April 17 Apr 17 – May 1
Direct Sow April 10 Apr 10 – May 1
Harvest July 31 Jul 31 – Sep 4

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Natural rainfall sufficient

📅 Days to Maturity

100–120 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 8a

📆 Growing Season

217 days in Baltimore City

Growing Tips for Hubbard Squash in Baltimore City

Direct sow Hubbard Squash outdoors after April 03 in Baltimore City when soil has warmed and frost danger has passed.

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

General growing tips

Start seeds indoors in short-season areas. Requires ample space and rich soil. Harvest when the skin is very hard and the color is deep. Cure in the sun before storing.

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Hubbard Squash in Baltimore City, MD?

Baltimore City is in Zone 8a with an average last frost of April 3. Plan your Hubbard Squash planting based on this frost date — see the calendar above for exact timing.

What planting zone is Baltimore City, MD?

Baltimore City, Maryland is in USDA Hardiness Zone 8a. The average last spring frost is April 3 and first fall frost is November 6.

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Your Baltimore City Garden Planner — Free

A 24-page printable planner built for Baltimore City (Zone 8a). 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 Baltimore City, MD. Local conditions may vary. Last updated: May 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.