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When to Plant Basil in Heppner, OR

Basil
Morrow County, Oregon Zone 7b July

July in the garden — Morrow County, Oregon

If you only do a handful of things in the garden this July, make it these. They're sequenced around your zone's frost timing.

Avg. last frost April 25
Avg. first frost October 15
Soil temp (4") 76°F
Watering Critical
Pest pressure High
Daylight 15.1 hrs
  1. Start harvesting basil

    Taste as you pick. The first ripe produce is the best feedback loop you'll get all season.

Coming up in August — start thinking about
  • First harvests: basil

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Basil is a fragrant warm-season herb essential to Italian and Thai cuisines. It comes in many varieties including sweet, Thai, purple, and lemon types.

Heppner, Oregon is in USDA Zone 7b. The average last spring frost is April 25 and the first fall frost is October 15, giving you a growing season of approximately 173 days.

At an elevation of 2,335 feet, Morrow County receives approximately 20.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 88°F, providing good warmth for Basil during the growing season.

Heppner, OR (Zone 7b) Moderate season
173 days
Last Spring Frost April 25
173 growing days
First Fall Frost October 15

Heppner Soil Profile

Soil Type

Silt Loam

Soil pH

5.4-6.8

Drainage

Well Drained

Basil Planting Risk Windows

Early Start (70% safe) ✓ Fits season (41 days to spare)
Start indoors: Feb 24 Transplant: Apr 28 🍅 Harvest: Jun 23 – Aug 25
Recommended (50%) ✓ Fits season (40 days to spare)
Start indoors: Mar 7 Transplant: May 9 🍅 Harvest: Jul 4 – Sep 5
Safe Start (90%) ✓ Fits season (41 days to spare)
Start indoors: Mar 25 Transplant: May 27 🍅 Harvest: Jul 22 – Sep 23

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 Heppner

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

Soil pH

Your soil pH (5.4–6.8) overlaps with Basil's range (6.0–7.0), though not a perfect match.

Soil Texture

The silt loam soil in Morrow County is excellent for Basil — good drainage, moisture retention, and nutrient holding capacity.

Drainage

Drainage is adequate for Basil.

Organic Matter

Organic matter is excellent (4.6%) — Basil will thrive.

How to Plant Basil

0.5"
Planting Depth
8"
Between Plants
12"
Between Rows

Succession Planting Basil

4
successive plantings in your 173-day season

Sow every 5.7 weeks. Last sowing by Aug 01 to harvest before frost.

Basil Water Budget

Plant needs
0.6″/week
Rainfall provides
0.5″/week
You supply
0.3″/week
Watering frequency 1-2 times/week
Season total 504 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Basil

Basil needs approximately 0.6 inches of water per week (2.6" per month). Here's how your county's rainfall compares month by month.

Month Basil Needs Rainfall You Supplement Action
Jan 3" 0" ❄️ Dormant
Feb 2.8" 0" ❄️ Dormant
Mar 2.1" 0" ❄️ Dormant
Apr 2.6" 1.4" 1.2" 💧 Light watering
May 2.6" 1.2" 1.4" 🚿 Regular watering
Jun 2.6" 0.7" 1.9" 🚿 Regular watering
Jul 2.6" 0.4" 2.2" 🚿 Regular watering
Aug 2.6" 0.4" 2.2" 🚿 Regular watering
Sep 2.6" 0.8" 1.8" 🚿 Regular watering
Oct 2.6" 1.7" 0.9" 💧 Light watering
Nov 3.2" 0" ❄️ Dormant
Dec 3.2" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Morrow County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Basil 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.

Basil needs ~1,000 GDD — county provides 2,768 GDD Excellent fit

Basil Planting Timeline — Heppner, OR

Basil Planting Calendar

Activity When Date Range
Start Indoors March 7 Mar 7 – Mar 21
Transplant Outdoors May 9 May 9 – May 23
Direct Sow May 2 May 2 – May 23
Harvest July 4 Jul 4 – Sep 5

Plant 0.5" deep · 8" apart · Rows 12" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.6"/week · 1-2 times/week

📅 Days to Maturity

50–75 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 7b

📆 Growing Season

173 days in Morrow County

Growing Tips for Basil in Heppner

Direct sow Basil outdoors after April 25 in Morrow County when soil has warmed and frost danger has passed.

General growing tips

Start seeds indoors or direct sow after last frost. Pinch flower buds to extend leaf production. Harvest leaves from the top down, cutting just above a leaf pair.

Companion Planting

Good Companions

Avoid Planting Near

  • Rue
  • Sage

Check more plant combinations with our Companion Planting Checker →

🌾 Save Your Own Basil Seeds
Life Cycle Annual
Pollination Self-Pollinating
How to Collect Let flower spikes dry brown on the plant.
Storage Store airtight; viable 5 years at 35°F, under 45% humidity.

Isolate 150 ft between varieties. Different basil species can cross.

🌱

Your Morrow County Garden Planner — Free

A 22-page printable planner built for Morrow County (Zone 7b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

Instant PDF download. No spam, unsubscribe any time.

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