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When to Plant Cress in Pennington County, SD

Pennington County, South Dakota Zone 5a May

May in Pennington County, South Dakota — your action list

We've pulled the most time-sensitive tasks for Pennington County, South Dakota this May and put them front and centre. Tackle them in order.

Avg. last frost May 14
Avg. first frost October 1
Soil temp (4") 54°F
Watering Moderate
Pest pressure Low
Daylight 14.6 hrs
  1. Move cress from tray to bed

    Frost risk is low now in Pennington County, South Dakota. If you've been covering beds overnight, you can stop.

  2. Start harvesting cress

    Taste as you pick. The first ripe produce is the best feedback loop you'll get all season.

Get ahead of June
  • Starting indoors: cress
  • First harvests: cress

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Garden cress is one of the fastest-growing edibles, producing peppery sprouts in as little as two weeks. It is excellent for microgreens and garnishes.

Pennington County, South Dakota is in USDA Zone 5a. The average last spring frost is May 14 and the first fall frost is October 1, giving you a growing season of approximately 140 days.

At an elevation of 976 feet, Pennington County receives approximately 33.7 inches of rainfall annually with predominantly loam soil. Summer highs average 83°F, so choose short-season varieties of Cress to ensure they mature before fall.

Pennington County, SD (Zone 5a) Short season
140 days
Last Spring Frost May 14
140 growing days
First Fall Frost October 1
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Pennington County Soil Profile

Soil Type

Loam

Soil pH

6.3-7.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (99 days to spare)
Start indoors: Apr 5 Transplant: May 10 🍅 Harvest: May 24 – Jun 14
Recommended (50%) ✓ Fits season (105 days to spare)
Start indoors: Apr 9 Transplant: May 14 🍅 Harvest: May 28 – Jun 18
Safe Start (90%) ✓ Fits season (103 days to spare)
Start indoors: Apr 21 Transplant: May 26 🍅 Harvest: Jun 9 – Jun 30

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 Pennington County

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

Soil pH

Your soil pH (6.3–7.7) overlaps with Cress's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (3.7%). Annual compost additions will help Cress.

How to Plant Cress

0.5"
Planting Depth
2"
Between Plants
6"
Between Rows

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

Succession Planting Cress

12
successive plantings in your 140-day season

Sow every 1.6 weeks. Last sowing by Sep 10 to harvest before frost.

For a dedicated fall crop, sow by Jul 23.

Plant Water Budget

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

Water stress score is 8/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Cress

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

Month Cress Needs Rainfall You Supplement Action
Jan 2.2" 0" ❄️ Dormant
Feb 2" 0" ❄️ Dormant
Mar 3" 0" ❄️ Dormant
Apr 3.7" 0" ❄️ Dormant
May 4.3" 3.6" 0.7" 💧 Light watering
Jun 4.3" 2" 2.3" 🚿 Regular watering
Jul 4.3" 3.1" 1.2" 💧 Light watering
Aug 4.3" 3.5" 0.8" 💧 Light watering
Sep 4.3" 3" 1.3" 💧 Light watering
Oct 4.3" 3.2" 1.1" 💧 Light watering
Nov 2.2" 0" ❄️ Dormant
Dec 2.2" 0" ❄️ Dormant

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

Cress 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.

Cress needs ~214 GDD — county provides 1,715 GDD Excellent fit

Cress Planting Timeline — Pennington County, SD

Cress Planting Calendar

Activity When Date Range
Start Indoors April 9 Apr 9 – Apr 23
Transplant Outdoors May 14 May 14 – May 28
Direct Sow April 30 Apr 30 – May 21
Harvest May 28 May 28 – Jun 18
Fall Sowing July 23 Jul 23 – Aug 6

Plant 0.5" deep · 2" apart · Rows 6" apart

Month-by-Month Timeline

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

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1"/week · Natural rainfall sufficient

📅 Days to Maturity

14–21 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 5a

📆 Growing Season

140 days in Pennington County

Growing Tips for Cress in Pennington County

Direct sow Cress outdoors after May 14 in Pennington County when soil has warmed and frost danger has passed.

Your generous 140.0-day season in Pennington County allows multiple plantings of Cress. Sow every 7.0 days for continuous harvest.

Common pests for Cress in this region include cabbage worm and flea beetles. Use row covers early in the season and inspect plants weekly.

General growing tips

Sow seeds thickly on moist soil or paper towels. Keep moist and harvest when 2-3 inches tall. Succession sow every few days for continuous supply. Grows well indoors year-round.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Cress in Pennington County, SD?

Pennington County is in Zone 5a with an average last frost of May 14. Plan your Cress planting based on this frost date — see the calendar above for exact timing.

What planting zone is Pennington County, SD?

Pennington County, South Dakota is in USDA Hardiness Zone 5a. The average last spring frost is May 14 and first fall frost is October 1.

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Your Pennington County Garden Planner — Free

A 24-page printable planner built for Pennington County (Zone 5a). 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 Pennington County, SD. 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.