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When to Plant Fava Beans in King County, TX

Fava beans are a cool-season legume with large, meaty beans inside thick pods. They fix nitrogen in the soil and are one of the oldest cultivated crops.

King County, Texas is in USDA Zone 7b. The average last spring frost is March 31 and the first fall frost is November 7, giving you a growing season of approximately 221 days.

At an elevation of 3,170 feet, King County receives approximately 60.2 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 99ยฐF, so Fava Beans may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring โ€” great for early planting โ€” but Fava Beans will need more frequent watering and organic matter to retain nutrients. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Fava Beans root diseases.

King County, TX (Zone 7b) Long season
221 days
Last Spring Frost March 31
221 growing days
First Fall Frost November 7

King County Soil Profile

Soil Type

Sandy Loam

Soil pH

7.8-8.4

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (103 days to spare)
Start indoors: Feb 16 Transplant: Mar 23 🍅 Harvest: Jun 8 – Jul 20
Recommended (50%) ✓ Fits season (102 days to spare)
Start indoors: Feb 24 Transplant: Mar 31 🍅 Harvest: Jun 16 – Jul 28
Safe Start (90%) ✓ Fits season (102 days to spare)
Start indoors: Mar 11 Transplant: Apr 15 🍅 Harvest: Jul 1 – Aug 12

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 King County

How your county's soil matches Fava Beans's growing requirements.

Soil pH

Your soil pH (7.8โ€“8.4) is more alkaline than Fava Beans prefers (6.0โ€“7.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

Organic Matter

Organic matter is low (1.1%). Add 2-3 inches of compost before planting Fava Beans.

How to Plant Fava Beans

1"
Planting Depth
15"
Between Plants
24"
Between Rows

Fall planting: Sow 10 weeks before your first frost date for a fall harvest.

Succession Planting Fava Beans

3
successive plantings in your 221-day season

Sow every 8.6 weeks. Last sowing by Jul 30 to harvest before frost.

For a dedicated fall crop, sow by Aug 29.

Plant Water Budget

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

Water stress score is 6/10 โ€” consider drought-tolerant varieties and mulching

Monthly Watering Guide for Fava Beans

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

Month Fava Beans Needs Rainfall You Supplement Action
Jan โ€” 4.7" 0" โ„๏ธ Dormant
Feb โ€” 3.2" 0" โ„๏ธ Dormant
Mar 4.3" 3.9" 0.4" ๐Ÿ’ง Light watering
Apr 4.3" 2.3" 2" ๐Ÿ’ง Light watering
May 4.3" 1.5" 2.8" ๐Ÿšฟ Regular watering
Jun 4.3" 2.2" 2.1" ๐Ÿ’ง Light watering
Jul 4.3" 10.4" 0" โœ… Rainfall sufficient
Aug 4.3" 11.5" 0" โœ… Rainfall sufficient
Sep 4.3" 8.1" 0" โœ… Rainfall sufficient
Oct 4.3" 5.7" 0" โœ… Rainfall sufficient
Nov 4.3" 3" 1.3" ๐Ÿ’ง Light watering
Dec โ€” 3.7" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Marโ€“Nov in King County). Supplement amounts are based on average rainfall โ€” actual needs vary with temperature, soil, and mulching.

Fava Beans 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" โ€” every day above 50ยฐF 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.

Fava Beans needs ~2,122 GDD — county provides 5,359 GDD Excellent fit

Fava Beans Planting Timeline โ€” King County, TX

Fava Beans Planting Calendar

Activity When Date Range
Start Indoors February 24 Feb 24 โ€“ Mar 10
Transplant Outdoors March 31 Mar 31 โ€“ Apr 14
Direct Sow March 17 Mar 17 โ€“ Apr 7
Harvest June 16 Jun 16 โ€“ Jul 28
Fall Sowing August 29 Aug 29 โ€“ Sep 12

Plant 1" deep ยท 15" apart ยท Rows 24" apart

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

1"/week ยท Natural rainfall sufficient

๐Ÿ“… Days to Maturity

75โ€“100 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: too_alkaline

๐Ÿ—บ๏ธ USDA Zone

Zone 7b

๐Ÿ“† Growing Season

221 days in King County

Growing Tips for Fava Beans in King County

Direct sow Fava Beans outdoors after March 31 in King County when soil has warmed and frost danger has passed.

Sandy soil in King County dries quickly โ€” mulch Fava Beans with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.

With summer highs reaching 99ยฐF in King County, provide afternoon shade for Fava Beans and water deeply in the morning.

Common pests for Fava Beans in this region include bean beetles and aphids. Use row covers early in the season and inspect plants weekly.

General growing tips

Direct sow as early as soil can be worked in spring. Pinch growing tips when pods begin to form to redirect energy and reduce aphid problems. Stake tall varieties.

Companion Planting

Good Companions

Avoid Planting Near

  • Onion
  • Garlic

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Fava Beans in King County, TX?

King County is in Zone 7b with an average last frost of March 31. Plan your Fava Beans planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is King County, TX?

King County, Texas is in USDA Hardiness Zone 7b. The average last spring frost is March 31 and first fall frost is November 7.

๐ŸŒฑ

Plan Your Garden with Confidence

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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 King County, TX. Local conditions may vary. Last updated: April 2026.