When to Plant Cress in Jefferson County, MT
Your May planting checklist for Jefferson County, Montana
Here's what deserves your attention in Jefferson County, Montana this month. Everything below is tailored to Zone 5a and timed around your local frost dates.
Looking ahead to June
- Transplants going out: cress
- Direct-sowing: cress
- First harvests: cress
- Fall sowing: cress
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, Montana is in USDA Zone 5a. The average last spring frost is June 15 and the first fall frost is September 7, giving you a growing season of approximately 84 days.
At an elevation of 7,214 feet, Jefferson County receives approximately 21.5 inches of rainfall annually with predominantly loam soil. Summer highs average 82°F, so choose short-season varieties of Cress to ensure they mature before fall.
Jefferson 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 Jefferson County
How your county's soil matches Cress's growing requirements.
Soil pH
Your soil pH (6.4–7.9) is more alkaline than Cress prefers (6.0–7.0). Add sulfur or peat moss to lower pH.
Soil Texture
The loam soil in Jefferson County is excellent for Cress — good drainage, moisture retention, and nutrient holding capacity.
Drainage
Drainage is adequate for Cress.
Organic Matter
Organic matter is moderate (2.5%). Annual compost additions will help Cress.
How to Plant Cress
Fall planting: Sow 10 weeks before your first frost date for a fall harvest.
Succession Planting Cress
Sow every 1.6 weeks. Last sowing by Aug 17 to harvest before frost.
For a dedicated fall crop, sow by Jun 29.
Plant Water Budget
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 | — | 1.5" | 0" | ❄️ Dormant |
| Feb | — | 1.4" | 0" | ❄️ Dormant |
| Mar | — | 2" | 0" | ❄️ Dormant |
| Apr | — | 2" | 0" | ❄️ Dormant |
| May | — | 2.5" | 0" | ❄️ Dormant |
| Jun | 4.3" | 1.5" | 2.8" | 🚿 Regular watering |
| Jul | 4.3" | 2" | 2.3" | 🚿 Regular watering |
| Aug | 4.3" | 2" | 2.3" | 🚿 Regular watering |
| Sep | 4.3" | 2" | 2.3" | 🚿 Regular watering |
| Oct | — | 1.8" | 0" | ❄️ Dormant |
| Nov | — | 1.4" | 0" | ❄️ Dormant |
| Dec | — | 1.4" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Jun–Sep in Jefferson 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 Planting Timeline — Jefferson County, MT
Cress Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | May 11 | May 11 – May 25 |
| Transplant Outdoors | June 15 | Jun 15 – Jun 29 |
| Direct Sow | June 1 | Jun 1 – Jun 22 |
| Harvest | June 29 | Jun 29 – Jul 20 |
| Fall Sowing | June 29 | Jun 29 – Jul 13 |
Plant 0.5" deep · 2" apart · Rows 6" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | — |
| May | Start Indoors |
| June | Transplant Outdoors Direct Sow Fall Sowing Harvest |
| July | Fall Sowing Harvest |
| August | — |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Partial Shade (3-6 hours)
💧 Water
1"/week · Only during dry spells
📅 Days to Maturity
14–21 days
🧪 Soil pH
Needs 6–7 · Your soil: too_alkaline
🗺️ USDA Zone
Zone 5a
📆 Growing Season
84 days in Jefferson County
Growing Tips for Cress in Jefferson County
Direct sow Cress outdoors after June 15 in Jefferson County when soil has warmed and frost danger has passed.
Your generous 84.0-day season in Jefferson 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.
Jefferson County receives only 22" of rain annually. Cress needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.
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 →
Cress in Other Locations
Frequently Asked Questions
When should I plant Cress in Jefferson County, MT?
Jefferson County is in Zone 5a with an average last frost of June 15. Plan your Cress planting based on this frost date — see the calendar above for exact timing.
What planting zone is Jefferson County, MT?
Jefferson County, Montana is in USDA Hardiness Zone 5a. The average last spring frost is June 15 and first fall frost is September 7.
Your Jefferson County Garden Planner — Free
A 24-page printable planner built for Jefferson 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.