Skip to content
🌻 Flower easy

Growing Sunflower in Spokane

🇺🇸 Zone 3 Planting Guide · Cold semi-arid climate

USDA Zone 3 155 frost-free days 70-100 days to harvest

Quick Answer: Growing Sunflower in Spokane

Yes, you can grow Sunflower in Spokane, US! Plant during May, Jun, Jul, Aug for best results. Spokane is in USDA Zone 3 with a Cold semi-arid climate, offering 155 frost-free days per year. The difficulty level is easy, and Sunflower takes 70-100 days to harvest. Sunflower needs full sun and moderate watering.

Climate Match Analysis

Moderate Match Spokane + Sunflower

Spokane's climate requires careful timing. Winter lows (-8°C) drop below Sunflower's minimum (8°C), so avoid cold months. Follow the recommended planting months for success.

Sunflower tolerates 8°C to 35°C
Optimal: 18°C - 28°C
Spokane range -8°C to 30°C

Spokane Climate Data

USDA Zone
3
Frost-Free
155days
Winter Low
-8°C
Summer High
30°C
Rainfall
432mm/yr
Climate
BSk
Cold semi-arid

Sunflower Planting Calendar for Spokane

Green months show the best time to plant Sunflower in Spokane

Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Plant Sunflower Not recommended

Sunflower Growing Requirements

☀️

Sunlight

Full Sun

6+ hours direct sunlight

💧

Water

Moderate

Keep soil consistently moist

📅

Days to Harvest

70-100

From planting to first harvest

📊

Difficulty

easy

Great for beginners

💡 Growing Tips for Sunflower

Sow directly -- taproots don't transplant well. Great for kids to grow. Wait until soil warms to at least 18°C before transplanting outdoors — cold soil stunts growth and can invite root rot. Water steadily but avoid soggy soil. A 5-cm layer of organic mulch helps balance moisture and suppress weeds.

Frost tolerance: Sunflower is NOT frost tolerant — wait until after the last frost in Spokane.

🤝

Companion Plants for Sunflower

Find out which plants grow best alongside Sunflower — and which to keep apart

🏠

Grow Sunflower Indoors

No garden? Learn how to grow Sunflower indoors with our complete guide

How to Grow Sunflower in Spokane

Spokane, US is in USDA Hardiness Zone 3 with a Cold semi-arid climate (Köppen BSk). With winter lows of -8°C and summer highs of 30°C, the growing season spans approximately 155 frost-free days. Sunflower is one of the easiest plants to grow in this climate.

Sunflower thrives in temperatures between 18°C and 28°C, requiring full sun and moderate watering. In Spokane, the best months to plant Sunflower are May, June, July, August. Sunflower is not frost tolerant, so it's important to wait until after the last spring frost before transplanting outdoors. Expect to harvest in approximately 70-100 days after planting.

Spokane receives only 432mm of annual rainfall, so consistent irrigation will be essential for growing Sunflower successfully.

Other Plants That Grow in Spokane

More plants you can grow alongside Sunflower in Spokane

Keep Exploring

Frequently Asked Questions

Can I grow sunflower in Spokane?

Yes! Sunflower can be successfully grown in Spokane, US. Spokane is in USDA Hardiness Zone 3 with a Cold semi-arid climate. The difficulty level for growing Sunflower here is rated "easy". The best months to plant are May, June, July, August.

When should I plant sunflower in Spokane?

In Spokane, the recommended planting months for Sunflower are May, June, July, August. Spokane has 155 frost-free days per year, with winter lows of -8°C and summer highs of 30°C. Since Sunflower is not frost tolerant, make sure to plant after the last frost date.

How long does sunflower take to grow in Spokane?

Sunflower typically takes 70-100 days from planting to harvest. In Spokane's Cold semi-arid climate with 155 frost-free days, you have enough time with good planning to grow Sunflower to maturity. Sow directly -- taproots don't transplant well. Great for kids to grow. Wait until soil warms to at least 18°C before transplanting outdoors — cold soil stunts growth and can invite root rot. Water steadily but avoid soggy soil. A 5-cm layer of organic mulch helps balance moisture and suppress weeds.

Can I grow sunflower indoors in Spokane?

Sunflower can potentially be grown indoors in Spokane with proper conditions. It requires full sun (6+ hours of direct light — a south-facing window or grow lights recommended). Indoor growing extends your season beyond the May, Jun, Jul, Aug outdoor planting window. Use containers with good drainage and moderate watering.

What month do I plant sunflower in Spokane?

Plant Sunflower in Spokane during May, June, July, August. These are the optimal months based on Spokane's USDA Zone 3 climate, 155 frost-free days, and temperature range of -8°C to 30°C.

Is sunflower hard to grow in Spokane?

Sunflower is rated "easy" to grow in Spokane. This is a great choice for beginners — it is forgiving and adapts well to this climate. The climate match for Sunflower in Spokane is Moderate.

What grows well with sunflower in Spokane?

In Spokane, you can grow many companion plants alongside Sunflower. Good options from the same planting window include Tomato, Basil, Lettuce, Carrot and 2 more. These plants share similar planting months and thrive in Spokane's Zone 3 climate.

Does sunflower need full sun in Spokane?

Sunflower requires full sun. In Spokane, provide at least 6 hours of direct sunlight daily. Most garden locations with southern exposure will work well.

Last updated: March 2026 · Climate data from NOAA, FAO, USDA

See an error? Report it