When to Plant Parsley in Colorado (2026 Guide)

Growing parsley in Colorado can be a rewarding endeavor, especially for gardeners who want to season their dishes with fresh herbs. Understanding the local climate and frost dates is essential for successful cultivation. In many parts of Colorado, such as Denver and Aurora, the median last spring frost occurs around May 5, while the first fall frost typically arrives by October 1. This data highlights the limited growing season, making it crucial to plan accordingly.

Parsley thrives best when planted at the appropriate times during Colorado's growing season. By starting seeds indoors or transplanting them outside after the last frost, gardeners can enjoy lush, flavorful growth. It's important to note that parsley is a biennial herb but is often treated as an annual in Colorado gardens. The fresh leaves produced the first year are most desirable for culinary use, while second-year plants bolt and produce flowers with less flavorful foliage.

With various hardiness zones across Colorado, including Zones 5b and 6a, there are tailored planting windows that maximize your parsley yield. For example, in areas like Grand Junction with a hardiness zone of 6a, gardeners can start parsley seeds indoors as early as late March, transitioning outdoors after the last frost. Each zone has unique conditions that affect the success of parsley, making zone-specific guidelines essential.

Planting Schedule by USDA Zone in Colorado

Zone	Indoor start	Transplant out	Direct sow	Harvest
Zone 5b	Start March 15 – March 31, ~6–8 weeks before May 5	Transplant outdoors May 15 – May 25, after May 5	Direct sow seeds outdoors May 15 – June 15, after May 5	Harvest from June 20 – October 1, before October 1
Zone 5a	Start April 1 – April 15, ~6–8 weeks before May 17	Transplant outdoors May 25 – June 5, after May 17	Direct sow seeds outdoors May 25 – June 15, after May 17	Harvest from July 1 – September 27, before September 27
Zone 6a	Start March 15 – March 31, ~6–8 weeks before April 25	Transplant outdoors May 1 – May 10, after April 25	Direct sow seeds outdoors May 1 – May 15, after April 25	Harvest from June 10 – October 16, before October 16

Parsley Planting Windows in Colorado

Indoor start: For Colorado gardeners, the ideal indoor seed starting window for parsley is from March 15 to April 15, depending on your zone.
Transplant outdoors: Transplanting parsley outdoors should be done from May 1 to June 5 to ensure it is past the last expected frost.
Harvest: Harvest parsley from June 10 to October 16, ensuring all leaves are picked before the first fall frost.

Common Mistakes Growing Parsley in Colorado

Many Colorado gardeners plant parsley too late, thinking spring lasts longer than it does. Waiting until after May 5 can prevent successful germination. Be sure to pay attention to your zone's frost date to avoid losing your crop.
Ignoring the soil conditions can lead to issues with parsley development. Colorado's often alkaline soil can hinder growth unless amended with organic matter. Testing your soil pH and adjusting accordingly will enhance your parsley's growth potential considerably.
Another mistake is not soaking parsley seeds before planting. This crucial step breaks dormancy and can significantly improve germination rates, reducing wait time from weeks to just over a week. Proper preparation can boost your herb garden's overall output.
Some gardeners underestimate the effects of sudden late spring snows in Colorado. These unexpected frosts can devastate young plants. Having frost cloths ready to protect young seedlings can save your parsley from premature chilling damage.
Many people overlook the importance of proper spacing when growing parsley, leading to poor air circulation and increased disease risk. In Colorado's dry climate, good air flow is essential to prevent mildew and promote healthy growth.

Frequently Asked Questions

What if I'm in a cold pocket of Colorado?

If you're in a cooler area, start your parsley seeds indoors and transplant them at the appropriate time. Monitor local frost dates closely, and consider using row covers to provide extra warmth during unexpected chill.

Can I still plant parsley in May?

Yes, you can plant parsley in May. Just ensure you've passed the last frost date in your specific zone and that the soil has warmed up adequately. It’s essential to keep an eye on local weather patterns for unexpected frosts.

How long does it take for parsley to germinate?

Parsley typically takes 10 to 21 days to germinate, depending on conditions. Soaking the seeds before planting can significantly reduce this time, making for a quicker start in your garden.

Can I grow parsley in containers?

Absolutely! Parsley grows quite well in containers, allowing flexible gardening options in Colorado. Use a pot with good drainage and ensure it receives ample sunlight for healthy growth. Move indoors before the frost to extend your harvest.

What is the best way to harvest parsley?

When harvesting parsley, always take leaves from the outer stems, cutting from the base. This promotes continued growth and ensures your plant remains healthy. Avoid harvesting more than one-third of the plant to prevent stress.

Keep Learning

Typical fall sowing window for Parsley in Colorado: June 22 – July 13.