When To Plant Spinach In Oregon – For Oregons Cool Seasons

Getting your spinach planting right is the key to a long and productive harvest in Oregon. Knowing exactly when to plant spinach in Oregon makes all the difference for our cool seasons.

Our climate is perfect for this leafy green. With a little planning, you can enjoy fresh spinach for much of the year. This guide gives you the simple timing and tips you need for success.

When To Plant Spinach In Oregon

Spinach is a cool-season crop that thrives in Oregon’s spring and fall. It bolts, or goes to seed, in summer heat. The goal is to grow it during cool, moist periods.

Spring Planting Dates

For a spring harvest, you need to get seeds in the ground early. Spinach seeds can germinate in soil temperatures as low as 40°F.

• Valley & Coastal Regions: Plant from late February through mid-April. You can start as soon as the soil is workable.
• High Elevations & Eastern Oregon: Aim for March through May, after the last hard frost has passed.

A common trick is to sow seeds every two weeks in early spring. This sucesion planting gives you a continuous harvest before summer heat arrives.

Fall Planting Dates

Fall is often the best and easiest time to grow spinach in Oregon. The days are getting cooler, and pests are less of a problem.

• Valley & Coastal Regions: Plant from mid-August through late September. This timing allows plants to mature in the cool autumn weather.
• High Elevations & Eastern Oregon: Aim for late July through August to beat the early frosts.

For a winter harvest, use cold frames or row covers over your fall planting. Spinach is very cold-tolerant and will often survive winter under protection.

Overwintering for an Early Spring Harvest

This is a favorite technique for Oregon gardeners. You plant spinach in the fall to harvest very early the next spring.

1. Plant seeds in October or early November.
2. Seeds may sprout and grow a bit before winter dormancy.
3. They’ll resume growth at the first hint of spring warmth.
4. You’ll be harvesting tender leaves long before spring-planted spinach is ready.

Choosing the Right Spinach Variety

Some varieties perform better in Oregon’s specific conditions. Look for bolt-resistant types for late spring planting.

• Savoy Types (crinkly leaves): ‘Bloomsdale’ is a classic, hardy heirloom perfect for fall and overwintering.
• Smooth-Leaf Types: ‘Space’ is great for easier cleaning and is slow to bolt.
• Semi-Savoy Types: ‘Tyee’ is an excellent, reliable hybrid known for its bolt resistance.

Step-by-Step Planting Guide

Follow these steps for a great start.

1. Site and Soil Preparation

Spinach needs full sun to partial shade. In warmer areas, afternoon shade can help prevent bolting. The soil should be rich and well-draining.

• Work in 2-3 inches of compost or well-rotted manure.
• Ensure the soil pH is between 6.5 and 7.0 for optimal growth.
• Rake the bed smooth to create a fine seedbed.

2. Sowing Seeds Directly

Spinach does not transplant well, so direct sowing is best.

1. Plant seeds ½ inch deep.
2. Space them about 1 inch apart in rows 12-18 inches apart.
3. You can also broadcast seeds over a wide row or bed.
4. Cover lightly with soil and pat down gently.
5. Water thoroughly with a gentle spray.

3. Germination and Thinning

Keep the soil consistently moist for germination, which takes 5-14 days. Once seedlings have their first true leaves, thin them.

• For baby leaves, thin to 2-3 inches apart.
• For full-size plants, thin to 4-6 inches apart.

Don’t waste the thinnings—they’re delicious in a salad!

Caring for Your Spinach

Consistent care ensures tender, sweet leaves.

Watering

Spinach needs about 1 inch of water per week. Use drip irrigation or soaker hoses to keep leaves dry and prevent disease. Water deeply and regularly, especially during dry spells in spring or fall.

Fertilizing

If your soil is prepared well, little extra fertilizer is needed. A side-dressing of a balanced organic fertilizer halfway through the growing season can give plants a boost if growth seems slow.

Weeding and Mulching

Keep beds weed-free, as spinach doesn’t compete well. A thin layer of straw or grass clippings helps retain moisture, suppress weeds, and keep soil cool. Mulch is especially helpful for fall plantings.

Common Pests and Problems

Oregon gardens face a few specific issues.

• Slugs and Snails: These are the number one pest. Use iron phosphate baits, beer traps, or hand-picking in the evening.
• Aphids: Blast them off with a strong spray of water or use insecticidal soap.
• Downy Mildew: This fungal disease appears as yellow spots. Choose resistant varieties, ensure good air circulation, and avoid overhead watering.
• Bolting: When days get long and hot, spinach sends up a seed stalk. Leaves turn bitter. The only solution is to harvest the plant and replant in the fall.

Harvesting Your Spinach

You can start harvesting whenever leaves are a size you like.

• Cut-and-Come-Again: Harvest outer leaves when they are 3-4 inches long, allowing the center to keep producing.
• Whole Plant: Cut the entire plant about an inch above the soil crown. It may regrow for a second, smaller harvest.

Always harvest in the morning when leaves are crisp and full of moisture. If a bolt stalk appears, harvest the entire plant immediately.

Frequently Asked Questions (FAQ)

Can you grow spinach in Oregon year-round?

With protection like cold frames or hoop houses, you can harvest spinach for much of the year, especially in milder western valleys. Summer is the main challenge due to heat.

What is the best month to plant spinach in Oregon?

For spring, March is ideal. For fall, September is often perfect. But the windows are wide, allowing for multiple plantings.

How late can you plant spinach in Oregon for fall?

You can plant until late September in the Willamette Valley. Use row covers to protect from early frosts and extend the season into December.

Does spinach grow well in Portland, Oregon?

Yes, Portland’s climate is excellent for spinach. The mild winters allow for fall, overwintered, and early spring crops with great success.

Should I start spinach seeds indoors?

It’s generally not recommended because spinach has a delicate taproot that dislikes disturbance. Direct sowing is simpler and more effective for this crop.

By following this Oregon-specific schedule, you’ll have a reliable source of fresh, healthy spinach. The key is to work with our cool seasons and avoid the summer heat. Get those seeds in the ground at the right time, and you’ll be rewarded with plentiful harvests.