When to Plant Broccoli in Benton County, OR
Broccoli is a nutrient-dense cool-season crop that produces large central heads followed by smaller side shoots. It is one of the most popular garden vegetables.
Benton County, Oregon is in USDA Zone 8b. The average last spring frost is April 14 and the first fall frost is October 30, giving you a growing season of approximately 199 days.
At an elevation of 97 feet, Benton County receives approximately 53.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85°F, providing good warmth for Broccoli during the growing season. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Broccoli root diseases.
Benton County Soil Profile
Soil Type
Silt Loam
Soil pH
5.6-6.2
Drainage
Well Drained
How Much Broccoli to Grow
For a family of 4, plant approximately 12 broccoli plants in about 24 sq ft. In Benton County's 199-day season, you'll have plenty of time for a full harvest. Plan your garden layout →
Monthly Watering Guide for Broccoli
Broccoli needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.
| Month | Broccoli Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 8.1" | 0" | ❄️ Dormant |
| Feb | — | 6.1" | 0" | ❄️ Dormant |
| Mar | — | 5.8" | 0" | ❄️ Dormant |
| Apr | 4.3" | 3.6" | 0.7" | 💧 Light watering |
| May | 4.3" | 3.3" | 1" | 💧 Light watering |
| Jun | 4.3" | 1.9" | 2.4" | 🚿 Regular watering |
| Jul | 4.3" | 0.9" | 3.4" | 🚿 Regular watering |
| Aug | 4.3" | 0.8" | 3.5" | 🚿 Regular watering |
| Sep | 4.3" | 2.3" | 2" | 💧 Light watering |
| Oct | 4.3" | 3.8" | 0.5" | 💧 Light watering |
| Nov | — | 8.3" | 0" | ❄️ Dormant |
| Dec | — | 8.2" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Benton County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Broccoli Planting Timeline — Benton County, OR
Broccoli Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 10 | Mar 10 – Mar 24 |
| Transplant Outdoors | April 14 | Apr 14 – Apr 28 |
| Direct Sow | March 31 | Mar 31 – Apr 21 |
| Harvest | June 16 | Jun 16 – Jul 28 |
| Fall Sowing | August 21 | Aug 21 – Sep 4 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors Direct Sow |
| April | Transplant Outdoors Direct Sow |
| May | — |
| June | Harvest |
| July | Harvest |
| August | Fall Sowing |
| September | Fall Sowing |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
Moderate — regular watering
📅 Days to Maturity
60–90 days
🧪 Soil pH
Needs 6–7 · Your soil: N/A
🗺️ USDA Zone
Zone 8b
📆 Growing Season
199 days in Benton County
Growing Tips for Benton County
Start seeds indoors 6-8 weeks before last frost. Provide consistent moisture to prevent hollow stems. Harvest heads before yellow flowers appear.
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Isolate 1/2 mile from other brassicas. Biennial — must overwinter roots.
Broccoli in Other Locations
Frequently Asked Questions
When should I plant Broccoli in Benton County, OR?
Benton County is in Zone 8b with an average last frost of April 14. Plan your Broccoli planting based on this frost date — see the calendar above for exact timing.
What planting zone is Benton County, OR?
Benton County, Oregon is in USDA Hardiness Zone 8b. The average last spring frost is April 14 and first fall frost is October 30.
Your Benton County Garden Planner — Free
A 22-page printable planner built for Benton 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.