When to Plant Watercress in Grand County, UT
Your May planting checklist for Grand County, Utah
Welcome to May in Zone 6b. These are the moves that will have the biggest impact on your growing season.
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Indoor seed-starting week for watercress
A seed-starting mix and a sunny window (or a grow light) are all you need. Keep soil warm — around 70°F — for fast germination.
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Start harvesting watercress
If you can't use it all right away, check the food-preservation section of your planner.
Get ahead of June
- First harvests: watercress
Watercress is a semi-aquatic plant with a peppery, tangy flavor rich in vitamins and minerals. It grows naturally along streams and can be cultivated in containers with standing water.
Grand County, Utah is in USDA Zone 6b. The average last spring frost is April 19 and the first fall frost is October 13, giving you a growing season of approximately 177 days.
At an elevation of 5,415 feet, Grand County receives approximately 23.1 inches of rainfall annually with predominantly loam soil. Summer highs average 91°F, providing good warmth for Watercress during the growing season.
Grand County Soil Profile
Soil Type
Loam
Soil pH
6.4-7.9
Drainage
Well Drained
Plant Planting Risk Windows
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 Grand County
How your county's soil matches Watercress's growing requirements.
Soil pH
Your soil pH (6.4–7.9) overlaps with Watercress's range (6.5–7.5), though not a perfect match.
Soil Texture
The loam soil in Grand County is excellent for Watercress — good drainage, moisture retention, and nutrient holding capacity.
Drainage
Watercress is a heavy drinker but your soil drains very quickly. Mulch heavily and consider drip irrigation.
Organic Matter
Organic matter is moderate (2.1%). Annual compost additions will help Watercress.
How to Plant Watercress
Fall planting: Sow 10 weeks before your first frost date for a fall harvest.
Succession Planting Watercress
Sow every 4.6 weeks. Last sowing by Aug 14 to harvest before frost.
For a dedicated fall crop, sow by Aug 04.
Plant Water Budget
Water stress score is 8/10 — consider drought-tolerant varieties and mulching
Monthly Watering Guide for Watercress
Watercress needs approximately 1.5 inches of water per week (6.5" per month). Here's how your county's rainfall compares month by month.
| Month | Watercress Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.6" | 0" | ❄️ Dormant |
| Feb | — | 1.3" | 0" | ❄️ Dormant |
| Mar | — | 2.2" | 0" | ❄️ Dormant |
| Apr | 6.5" | 2.2" | 4.3" | 🚿 Regular watering |
| May | 6.5" | 2.9" | 3.6" | 🚿 Regular watering |
| Jun | 6.5" | 1.5" | 5" | 🚿 Regular watering |
| Jul | 6.5" | 2.4" | 4.1" | 🚿 Regular watering |
| Aug | 6.5" | 2.1" | 4.4" | 🚿 Regular watering |
| Sep | 6.5" | 1.8" | 4.7" | 🚿 Regular watering |
| Oct | 6.5" | 2.1" | 4.4" | 🚿 Regular watering |
| Nov | — | 1.6" | 0" | ❄️ Dormant |
| Dec | — | 1.3" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Grand County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Watercress 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.
Watercress Planting Timeline — Grand County, UT
Watercress Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 15 | Mar 15 – Mar 29 |
| Transplant Outdoors | April 19 | Apr 19 – May 3 |
| Direct Sow | April 5 | Apr 5 – Apr 26 |
| Harvest | May 31 | May 31 – Jul 5 |
| Fall Sowing | August 4 | Aug 4 – Aug 18 |
Plant 0.5" deep · 6" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | Transplant Outdoors Direct Sow |
| May | Transplant Outdoors Harvest |
| June | Harvest |
| July | Harvest |
| August | Fall Sowing |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Partial Shade (3-6 hours)
💧 Water
1.5"/week · 2-3 times/week
📅 Days to Maturity
40–60 days
🧪 Soil pH
Needs 6.5–7.5 · Your soil: acceptable
🗺️ USDA Zone
Zone 6b
📆 Growing Season
177 days in Grand County
Growing Tips for Watercress in Grand County
Direct sow Watercress outdoors after April 19 in Grand County when soil has warmed and frost danger has passed.
Your generous 177.0-day season in Grand County allows multiple plantings of Watercress. Sow every 20.0 days for continuous harvest.
Common pests for Watercress in this region include cabbage worm and flea beetles. Use row covers early in the season and inspect plants weekly.
Grand County receives only 23" of rain annually. Watercress needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.
General growing tips
Grow in containers with trays of water kept fresh. Provide partial shade and cool conditions. Harvest stems by cutting above water level. Replace water frequently to prevent stagnation.
Companion Planting
Good Companions
Check more plant combinations with our Companion Planting Checker →
Watercress in Other Locations
Frequently Asked Questions
When should I plant Watercress in Grand County, UT?
Grand County is in Zone 6b with an average last frost of April 19. Plan your Watercress planting based on this frost date — see the calendar above for exact timing.
What planting zone is Grand County, UT?
Grand County, Utah is in USDA Hardiness Zone 6b. The average last spring frost is April 19 and first fall frost is October 13.
Your Grand County Garden Planner — Free
A 24-page printable planner built for Grand 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.