When to Plant Cress in Jefferson County, ID
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.
Jefferson County, Idaho is in USDA Zone 5a. The average last spring frost is May 22 and the first fall frost is September 21, giving you a growing season of approximately 122 days.
At an elevation of 5,094 feet, Jefferson County receives approximately 18 inches of rainfall annually with predominantly loam soil. Summer highs average 87°F, providing good warmth for Cress during the growing season. With low rainfall, drip irrigation is essential for growing Cress successfully. Mulch heavily to conserve soil moisture.
Jefferson County Soil Profile
Soil Type
Loam
Soil pH
6.3-7.8
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.
Plant Water Budget
Water stress score is 6/10 — consider drought-tolerant varieties and mulching
Cress Planting Timeline — Jefferson County, ID
Cress Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | April 17 | Apr 17 – May 1 |
| Transplant Outdoors | May 22 | May 22 – Jun 5 |
| Direct Sow | May 8 | May 8 – May 29 |
| Fall Sowing | July 13 | Jul 13 – Jul 27 |
| Harvest | June 5 | Jun 5 – Jun 26 |
Plant 0.5" deep · 2" apart · Rows 6" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | Start Indoors |
| May | Start Indoors Transplant Outdoors Direct Sow |
| June | Transplant Outdoors Harvest |
| July | Fall Sowing |
| August | — |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
Sun
Partial Shade (3-6 hours)
Water
Moderate — regular watering
Days to Maturity
14–21 days
Soil pH
6 – 7
USDA Zone
Zone 5a
Growing Season
122 days
Growing Tips for Jefferson County
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
Level Up Your Garden
Cress in Other Locations
Frequently Asked Questions
When should I plant Cress in Jefferson County, ID?
Jefferson County is in Zone 5a with an average last frost of May 22. Plan your Cress planting based on this frost date — see the calendar above for exact timing.
What planting zone is Jefferson County, ID?
Jefferson County, Idaho is in USDA Hardiness Zone 5a. The average last spring frost is May 22 and first fall frost is September 21.
Plan Your Garden with Confidence
Get our free Garden Planner — designed to help Jefferson County gardeners in Zone 5a organize planting dates, track what's growing, and never miss a planting window.
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