Best Time To Plant Cilantro In Idaho

Idaho gardeners find success with cilantro by sowing seeds in late April, when soil temperatures reach at least 50 degrees Fahrenheit. Knowing the best time to plant cilantro in idaho is the key to getting a big harvest before the summer heat ruins your plants. Cilantro is a cool-season herb that bolts quickly when temperatures rise, so timing is everything in Idaho’s unique climate.

This guide will walk you through exactly when to plant cilantro in each part of Idaho. You will learn about soil temps, frost dates, and how to keep your cilantro growing all season long. Let’s get started so you can enjoy fresh cilantro for your salsas and salads.

The absolute best time to plant cilantro in idaho is from late April through early May. This window works for most of the state, from Boise to Idaho Falls. You want to aim for soil temperatures around 50 to 55 degrees Fahrenheit.

Planting too early in cold, wet soil can cause seeds to rot. Planting too late means your cilantro will bolt as soon as the hot June weather arrives. A spring planting gives you about 6 to 8 weeks of harvest before the plant goes to seed.

Understanding Idaho’s Growing Zones

Idaho spans USDA hardiness zones 3 through 7. The northern panhandle and higher elevations are colder, while the Treasure Valley is warmer. Your exact planting date will shift by a week or two depending on your location.

Zone 3-4 (Northern Idaho, mountains): Plant in mid-to-late May
Zone 5-6 (Boise, Twin Falls, Lewiston): Plant in late April to early May
Zone 7 (warmer microclimates): Plant in early to mid-April

Check your local frost dates. Cilantro can handle a light frost, but it won’t survive a hard freeze. Wait until the last frost date has passed in your area.

Soil Temperature Is Your Best Guide

Don’t rely only on the calendar. Use a soil thermometer to check the temp at 2 inches deep. Cilantro seeds germinate best when the soil is between 50 and 70 degrees F.

If the soil is below 50 degrees, the seeds will sit there and may rot. If it’s above 85 degrees, germination rates drop fast. In Idaho, spring soil warms up slowly, so be patient.

You can warm the soil by covering it with black plastic for a week before planting. This trick works great for early spring plantings in cooler parts of Idaho.

Fall Planting For A Second Harvest

Many Idaho gardeners don’t realize they can plant cilantro again in late summer. A fall planting gives you fresh cilantro in September and October, when the weather cools down again.

The best time for a fall planting is from mid-August to early September. You want the seeds to germinate when soil is still warm, but the plants will grow in cooler autumn temperatures. Cilantro actually prefers the shorter days and mild temps of fall.

Count back 6 to 8 weeks from your first expected frost date
Plant seeds directly in the garden or in containers
Water regularly during the hot end of summer
Harvest until the first hard frost kills the plants

Fall cilantro often tastes sweeter and less bitter than spring crops. The cool weather slows down bolting, so you get more harvest time.

Succession Planting For Continuous Harvest

Instead of planting all your seeds at once, try succession planting. Sow a new row of cilantro every 2 to 3 weeks. This gives you a steady supply instead of one big harvest that bolts all at once.

Start your first planting in late April. Then plant another row in mid-May, and another in early June. For fall, start planting again in early August and continue into September.

This method works well because cilantro grows fast. You can have fresh leaves from spring through fall without any gaps. Just remember that the mid-summer plantings may bolt quickly, so focus on the spring and fall windows.

How To Plant Cilantro In Idaho Soil

Cilantro is easy to grow from seed. It doesn’t transplant well because of its taproot, so direct sowing is best. Here is a step-by-step guide for Idaho gardeners.

Choose a sunny spot with well-draining soil. Cilantro needs at least 6 hours of sun per day.
Prepare the soil by removing rocks and weeds. Mix in some compost for nutrients.
Sow seeds 1/4 inch deep and about 2 inches apart. You can thin them later.
Cover lightly with soil and water gently. Keep the soil moist but not soggy.
Seeds will germinate in 7 to 10 days if soil temps are right.
Thin seedlings to 4 to 6 inches apart once they have two sets of true leaves.

In Idaho’s clay-heavy soils, add some sand or perlite to improve drainage. Cilantro hates wet feet. Raised beds work great for this herb.

Watering And Care Tips

Cilantro needs consistent moisture, especially during germination. Once the plants are established, water deeply once or twice a week. Let the soil dry out slightly between waterings.

Mulch around the plants to keep the soil cool and moist. This is very helpful in Idaho’s hot summers. A layer of straw or grass clippings works well.

Fertilize lightly with a balanced organic fertilizer once a month. Too much nitrogen makes the leaves less flavorful. Cilantro is not a heavy feeder.

Dealing With Bolting In Idaho Summers

Bolting is when cilantro sends up a flower stalk and the leaves become bitter. This happens naturally when days get long and temperatures rise. In Idaho, bolting usually starts in late June or early July.

You can delay bolting by providing afternoon shade. Plant cilantro on the east side of taller plants like tomatoes or sunflowers. This gives it morning sun and afternoon shade.

Another trick is to keep the soil consistently moist. Stressed plants bolt faster. Regular watering and mulch help keep the plants happy longer.

Once you see flower buds forming, you can pinch them off. This buys you another week or two of leaf harvest. But eventually the plant will bolt no matter what you do.

Harvesting Cilantro The Right Way

Start harvesting when the plants are about 6 inches tall. Cut the outer leaves and stems first, leaving the inner ones to grow. Never cut more than one-third of the plant at once.

Use sharp scissors or garden shears. Cut stems close to the base. The plants will regrow for multiple harvests if you don’t take too much.

If you let some plants bolt, you can collect the seeds. These are coriander, which is a different spice. Let the flower heads dry on the plant, then shake the seeds into a bag.

Common Problems Growing Cilantro In Idaho

Cilantro is generally easy, but a few issues can pop up. Here are the most common problems Idaho gardeners face.

Poor germination: Usually caused by cold soil or overwatering. Wait for proper soil temps and water less.
Leggy plants: Not enough sun. Move to a sunnier spot next time.
Yellow leaves: Overwatering or poor drainage. Let soil dry out between waterings.
Pests: Aphids and spider mites can attack. Spray with water or use insecticidal soap.
Bitter taste: Usually from heat stress or bolting. Harvest earlier or provide shade.

Most problems are easy to fix. Cilantro is a forgiving herb if you give it the right conditions. Pay attention to your plants and adjust as needed.

Container Growing For Idaho Patios

If you don’t have garden space, grow cilantro in containers. This is a great option for apartment dwellers or people with small yards. Containers also let you move the plants to shade when it gets hot.

Use a pot that is at least 8 inches deep and has drainage holes. Fill with good quality potting soil. Sow seeds as you would in the ground.

Container cilantro needs more frequent watering than garden plants. Check the soil daily, especially in summer. A pot on a hot patio can dry out in hours.

You can also bring containers indoors during cold snaps. This extends your harvest into late fall. Place them on a sunny windowsill or under grow lights.

Best Cilantro Varieties For Idaho

Not all cilantro varieties are the same. Some are slower to bolt, which is a big advantage in Idaho’s climate. Here are the best choices for Idaho gardens.

Slow Bolt: Lives up to its name. Gives you weeks more harvest before bolting.
Calypso: Very slow to bolt. Great for spring and summer plantings.
Santo: Standard variety with good flavor. Reliable and easy to find.
Leisure: Another slow-bolt option. Compact plants for containers.
Vietnamese Cilantro: Not true cilantro but similar flavor. Grows well in heat.

Slow-bolt varieties are worth the extra cost. They can add 2 to 4 weeks to your harvest window. In Idaho’s short growing season, that makes a big difference.

Using A Cold Frame Or Row Cover

For early spring or late fall planting, use a cold frame or row cover. These protect your cilantro from frost and extend the season. You can plant 2 to 3 weeks earlier with a cold frame.

Row covers are lightweight fabric that lets light and water through. They add a few degrees of warmth. Cold frames are more substantial and offer better protection.

In northern Idaho, a cold frame can make the difference between a good harvest and no harvest. It’s a simple investment that pays off with fresh cilantro for months.

Frequently Asked Questions

Can I plant cilantro in Idaho in July?

July is too hot for most of Idaho. Cilantro will bolt quickly in summer heat. Wait until mid-August for a fall planting instead.

How late can I plant cilantro in Idaho?

You can plant as late as early September for a fall crop. Make sure you have at least 6 weeks before the first frost. In warmer parts of Idaho, you might get away with mid-September.

Does cilantro need full sun in Idaho?

It prefers full sun in spring and fall, but afternoon shade is helpful in summer. Morning sun with afternoon shade is ideal for extending the harvest.

Should I soak cilantro seeds before planting?

Soaking seeds for 24 hours can speed up germination. It’s optional but helpful, especially if your soil is on the dry side. Don’t soak longer than 24 hours.

Can I grow cilantro indoors in Idaho during winter?

Yes, you can grow cilantro indoors on a sunny windowsill. Use a pot with good drainage and provide 12 to 14 hours of light. Growth will be slower in winter.

Final Tips For Idaho Cilantro Success

Timing is everything with cilantro in Idaho. Plant in late April for spring, and again in late August for fall. Use slow-bolt varieties and provide afternoon shade to extend your harvest.

Keep the soil moist but not wet. Harvest regularly to encourage new growth. And don’t be afraid to let a few plants go to seed so you have coriander for cooking.

Cilantro is one of the easiest herbs to grow if you get the timing right. With a little planning, you can enjoy fresh cilantro from spring through fall. Your tacos, salsas, and curries will thank you.

Start preparing your garden bed now. Check your soil temperature in late April. Sow those seeds and watch them grow. You’ll be amazed at how much cilantro you can produce in a small space.

Remember that every year is a little different in Idaho. Some springs are warm early, others are cold and wet. Use the soil thermometer as your guide, not just the calendar. This simple tool will save you from planting too early or too late.

Happy gardening in the Gem State. Your cilantro patch is waiting for you.