When to Plant Watercress in Inyo County, CA
Your May planting checklist for Inyo County, California
Your garden in Inyo County, California is working on a schedule, even when you're not. Here's where you should be this May.
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.
Inyo County, California is in USDA Zone 8b. The average last spring frost is January 15 and the first fall frost is December 10, giving you a growing season of approximately 329 days.
At an elevation of 4,562 feet, Inyo County receives approximately 16.4 inches of rainfall annually with predominantly loam soil. Summer highs average 88°F, providing good warmth for Watercress during the growing season. With low rainfall, drip irrigation is essential for growing Watercress successfully. Mulch heavily to conserve soil moisture.
Inyo County Soil Profile
Soil Type
Loam
Soil pH
6-7.8
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 Inyo County
How your county's soil matches Watercress's growing requirements.
Soil pH
Your soil pH (6.0–7.8) overlaps with Watercress's range (6.5–7.5), though not a perfect match.
Soil Texture
The loam soil in Inyo County is excellent for Watercress — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (2.2%). 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 Oct 11 to harvest before frost.
For a dedicated fall crop, sow by Oct 01.
Plant Water Budget
Water stress score is 10/10 — 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 | 6.5" | 3.3" | 3.2" | 💧 Light watering |
| Feb | 6.5" | 3.4" | 3.1" | 💧 Light watering |
| Mar | 6.5" | 2.5" | 4" | 🚿 Regular watering |
| Apr | 6.5" | 1.3" | 5.2" | 🚿 Regular watering |
| May | 6.5" | 0.5" | 6" | 🚿 Regular watering |
| Jun | 6.5" | 0.1" | 6.4" | 🚿 Regular watering |
| Jul | 6.5" | 0" | 6.5" | 🚿 Regular watering |
| Aug | 6.5" | 0" | 6.5" | 🚿 Regular watering |
| Sep | 6.5" | 0.2" | 6.3" | 🚿 Regular watering |
| Oct | 6.5" | 0.6" | 5.9" | 🚿 Regular watering |
| Nov | 6.5" | 1.7" | 4.8" | 🚿 Regular watering |
| Dec | 6.5" | 2.8" | 3.7" | 🚿 Regular watering |
Water needs are for active growing months only (Jan–Dec in Inyo 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 — Inyo County, CA
Watercress Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | December 11 | Dec 11 – Dec 25 |
| Transplant Outdoors | January 15 | Jan 15 – Jan 29 |
| Direct Sow | January 1 | Jan 1 – Jan 22 |
| Harvest | February 26 | Feb 26 – Apr 2 |
| Fall Sowing | October 1 | Oct 1 – Oct 15 |
Plant 0.5" deep · 6" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | Transplant Outdoors Direct Sow |
| February | Harvest |
| March | Harvest |
| April | Harvest |
| May | — |
| June | — |
| July | — |
| August | — |
| September | — |
| October | Fall Sowing |
| November | — |
| December | Start Indoors |
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 8b
📆 Growing Season
329 days in Inyo County
Growing Tips for Watercress in Inyo County
Direct sow Watercress outdoors after January 15 in Inyo County when soil has warmed and frost danger has passed.
Your generous 330.0-day season in Inyo 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.
Inyo County receives only 16" 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 Inyo County, CA?
Inyo County is in Zone 8b with an average last frost of January 15. Plan your Watercress planting based on this frost date — see the calendar above for exact timing.
What planting zone is Inyo County, CA?
Inyo County, California is in USDA Hardiness Zone 8b. The average last spring frost is January 15 and first fall frost is December 10.
Your Inyo County Garden Planner — Free
A 24-page printable planner built for Inyo County (Zone 8b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.