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When to Plant Sorrel in Riley County, KS

Riley County, Kansas Zone 6b May

May in Riley County, Kansas — your action list

May is a pivotal month for Riley County, Kansas gardens. Focus on these tasks first and you'll set up the rest of the season for success.

Avg. last frost April 17
Avg. first frost October 18
Soil temp (4") 61°F
Watering Low
Pest pressure Low
Daylight 14.2 hrs
  1. Begin indoor sowing: sorrel

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

  2. Bring in the sorrel

    Morning harvests are best — cooler temperatures mean crisper produce and longer fridge life.

June will be here before you know it — start on
  • First harvests: sorrel

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Sorrel is a perennial herb with tangy, lemon-flavored arrow-shaped leaves. It is one of the first greens to emerge in spring and is used in soups and salads.

Riley County, Kansas is in USDA Zone 6b. The average last spring frost is April 17 and the first fall frost is October 18, giving you a growing season of approximately 184 days.

At an elevation of 551 feet, Riley County receives approximately 32.9 inches of rainfall annually with predominantly loam soil. Summer highs average 85°F, providing good warmth for Sorrel during the growing season.

Riley County, KS (Zone 6b) Moderate season
184 days
Last Spring Frost April 17
184 growing days
First Fall Frost October 18

Riley County Soil Profile

Soil Type

Loam

Soil pH

6.8-7.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (84 days to spare)
Start indoors: Mar 9 Transplant: Apr 6 🍅 Harvest: May 18 – Jul 20
Recommended (50%) ✓ Fits season (86 days to spare)
Start indoors: Mar 13 Transplant: Apr 10 🍅 Harvest: May 22 – Jul 24
Safe Start (90%) ✓ Fits season (85 days to spare)
Start indoors: Mar 28 Transplant: Apr 25 🍅 Harvest: Jun 6 – Aug 8

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 Riley County

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

Soil pH

Your soil pH (6.8–7.7) is more alkaline than Sorrel prefers (5.5–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

The loam soil in Riley County is excellent for Sorrel — good drainage, moisture retention, and nutrient holding capacity.

Drainage

Drainage is adequate for Sorrel.

Organic Matter

Organic matter is moderate (3.4%). Annual compost additions will help Sorrel.

How to Plant Sorrel

0.5"
Planting Depth
8"
Between Plants
12"
Between Rows

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

Succession Planting Sorrel

5
successive plantings in your 184-day season

Sow every 4.6 weeks. Last sowing by Aug 19 to harvest before frost.

For a dedicated fall crop, sow by Aug 09.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.8″/week
You supply
0.7″/week
Watering frequency 1-2 times/week
Season total 1,079 gal / 100 sq ft
Drought risk

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

Monthly Watering Guide for Sorrel

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

Month Sorrel Needs Rainfall You Supplement Action
Jan 1" 0" ❄️ Dormant
Feb 1.2" 0" ❄️ Dormant
Mar 2.3" 0" ❄️ Dormant
Apr 4.3" 3.1" 1.2" 💧 Light watering
May 4.3" 4.3" 0" ✅ Rainfall sufficient
Jun 4.3" 5.5" 0" ✅ Rainfall sufficient
Jul 4.3" 4" 0.3" 💧 Light watering
Aug 4.3" 4" 0.3" 💧 Light watering
Sep 4.3" 3.1" 1.2" 💧 Light watering
Oct 4.3" 2.3" 2" 💧 Light watering
Nov 1.2" 0" ❄️ Dormant
Dec 0.9" 0" ❄️ Dormant

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

Sorrel 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.

Sorrel needs ~688 GDD — county provides 2,530 GDD Excellent fit

Sorrel Planting Timeline — Riley County, KS

Sorrel Planting Calendar

Activity When Date Range
Start Indoors March 13 Mar 13 – Mar 27
Transplant Outdoors April 10 Apr 10 – Apr 24
Direct Sow April 3 Apr 3 – Apr 24
Harvest May 22 May 22 – Jul 24
Fall Sowing August 9 Aug 9 – Aug 23

Plant 0.5" deep · 8" apart · Rows 12" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1"/week · 1-2 times/week

📅 Days to Maturity

40–60 days

🧪 Soil pH

Needs 5.5–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 6b

📆 Growing Season

184 days in Riley County

Growing Tips for Sorrel in Riley County

Direct sow Sorrel outdoors after April 17 in Riley County when soil has warmed and frost danger has passed.

Your generous 184.0-day season in Riley County allows multiple plantings of Sorrel. Sow every 20.0 days for continuous harvest.

General growing tips

Direct sow in early spring or fall. Remove flower stalks promptly to encourage leaf production. Divide clumps every 3-4 years. Young leaves have the best flavor.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Sorrel in Riley County, KS?

Riley County is in Zone 6b with an average last frost of April 17. Plan your Sorrel planting based on this frost date — see the calendar above for exact timing.

What planting zone is Riley County, KS?

Riley County, Kansas is in USDA Hardiness Zone 6b. The average last spring frost is April 17 and first fall frost is October 18.

🌱

Your Riley County Garden Planner — Free

A 24-page printable planner built for Riley County (Zone 6b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

Instant PDF download. No spam, unsubscribe any time.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Riley County, KS. 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.