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When to Plant Cress in Multnomah County, OR

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.

Multnomah County, Oregon is in USDA Zone 8b. The average last spring frost is April 14 and the first fall frost is October 27, giving you a growing season of approximately 196 days.

At an elevation of 357 feet, Multnomah County receives approximately 35.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 84ยฐF, so choose short-season varieties of Cress to ensure they mature before fall.

Multnomah County, OR (Zone 8b) Moderate season
196 days
Last Spring Frost April 14
196 growing days
First Fall Frost October 27

Multnomah County Soil Profile

Soil Type

Silt Loam

Soil pH

5.8-6.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (158 days to spare)
Start indoors: Mar 4 Transplant: Apr 8 🍅 Harvest: Apr 22 – May 13
Recommended (50%) ✓ Fits season (161 days to spare)
Start indoors: Mar 10 Transplant: Apr 14 🍅 Harvest: Apr 28 – May 19
Safe Start (90%) ✓ Fits season (159 days to spare)
Start indoors: Apr 4 Transplant: May 9 🍅 Harvest: May 23 – Jun 13

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 Multnomah County

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

Soil pH

Your soil pH (5.8โ€“6.3) overlaps with Cress's range (6.0โ€“7.0), though not a perfect match.

Soil Texture

The silt loam soil in Multnomah County is excellent for Cress โ€” good drainage, moisture retention, and nutrient holding capacity.

Drainage

Drainage is adequate for Cress.

Organic Matter

Organic matter is excellent (4.5%) โ€” Cress will thrive.

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

17
successive plantings in your 196-day season

Sow every 1.6 weeks. Last sowing by Oct 06 to harvest before frost.

For a dedicated fall crop, sow by Aug 18.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.8″/week
You supply
0.5″/week
Watering frequency 1-2 times/week
Season total 926 gal / 100 sq ft
Cress needs ~228 GDD — county provides 2,548 GDD Excellent fit

Cress Planting Timeline โ€” Multnomah County, OR

Cress Planting Calendar

Activity When Date Range
Start Indoors March 10 Mar 10 โ€“ Mar 24
Transplant Outdoors April 14 Apr 14 โ€“ Apr 28
Direct Sow March 31 Mar 31 โ€“ Apr 21
Fall Sowing August 18 Aug 18 โ€“ Sep 1
Harvest April 28 Apr 28 โ€“ May 19

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Partial Shade (3-6 hours)

๐Ÿ’ง Water

1"/week ยท 1-2 times/week

๐Ÿ“… Days to Maturity

14โ€“21 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: acceptable

๐Ÿ—บ๏ธ USDA Zone

Zone 8b

๐Ÿ“† Growing Season

196 days in Multnomah County

Growing Tips for Cress in Multnomah County

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

Your generous 196.0-day season in Multnomah 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

Level Up Your Garden

Frequently Asked Questions

When should I plant Cress in Multnomah County, OR?

Multnomah County is in Zone 8b with an average last frost of April 14. Plan your Cress planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Multnomah County, OR?

Multnomah County, Oregon is in USDA Hardiness Zone 8b. The average last spring frost is April 14 and first fall frost is October 27.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Multnomah County gardeners in Zone 8b organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

Free download. Plan your entire garden season in minutes.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Multnomah County, OR. Local conditions may vary. Last updated: April 2026.