When to Plant Cilantro in Maine (2026 Guide)

Cilantro is a vibrant herb that thrives in cooler temperatures, making it a popular choice for many Maine gardens. Knowing the right time to plant cilantro is crucial since it bolts quickly when exposed to heat. In Maine, the last spring frost dates vary between areas, with Portland experiencing its final frost around May 8, while Lewiston sees it as early as April 27. Understanding these dates helps ensure a successful growing season for this aromatic herb.

In 2026, gardeners in Portland should plan to directly sow cilantro seeds outdoors after the last chance of frost has passed. Given its quick growth cycle and susceptibility to bolting, spacing out sowings every 2-3 weeks will provide continual harvests throughout the prime growing season in Maine. Remember that cilantro prefers cooler weather and a well-draining soil to develop its full flavor potential.

With an average frost-free season of about 150 days in Zone 5b and 164 days in Zone 6a, Maine presents both opportunities and challenges for growing cilantro. It requires careful timing to establish healthy plants before the peak heat of summer encourages them to bolt. By following the advice outlined in this guide, Maine gardeners can enjoy fresh cilantro while avoiding common pitfalls associated with planting and growing this delightful herb.

Planting Schedule by USDA Zone in Maine

Zone	Indoor start	Transplant out	Direct sow	Harvest
Zone 5b	Not recommended — direct sow only.	Not recommended — direct sow only.	Start March 15 – April 10, ~2–3 weeks after May 8.	Harvest June 1 – July 15, ~4–6 weeks after sowing.
Zone 6a	Not recommended — direct sow only.	Not recommended — direct sow only.	Start March 25 – April 15, ~2–3 weeks after April 27.	Harvest June 10 – July 20, ~4–6 weeks after sowing.

Cilantro Planting Windows in Maine

Indoor start: Not applicable as cilantro should not be started indoors.
Transplant outdoors: Not applicable as cilantro should not be transplanted outdoors.
Harvest: Expect to harvest cilantro from June 1 – July 20 in Zone 5b and June 10 – July 20 in Zone 6a.

Common Mistakes Growing Cilantro in Maine

Many new gardeners in Maine mistakenly believe they can start cilantro indoors. However, the truth is that cilantro has a taproot and does not transplant well, making direct sowing the best method for successful growth.
A frequent issue for Maine gardeners is waiting too long to sow seeds after the last frost. Remember that cilantro grows quickly and will bolt if it experiences excessive heat or long days, so planting times should be strictly adhered to for the best results.
Maine's all-too-common late spring snow events can surprise gardeners. These unexpected frosts may damage or kill young cilantro plants, so always check local forecasts and be ready to protect your sown seeds during fluctuating temperatures.
Many gardeners overlook the importance of soil conditions for cilantro in Maine. Well-drained, slightly acidic soil allows for optimal growth; heavy, clay soils can lead to poor establishment and increased risk of disease.
Some gardeners neglect to practice succession planting for cilantro in Maine. Since cilantro only lasts a few weeks before bolting, planting every 2-3 weeks is essential to ensure a steady supply of this herb throughout the growing season.

Frequently Asked Questions

What should I do if I'm in a cold pocket of Maine?

If you are in a colder area of Maine, consider starting your cilantro seeds slightly earlier in the spring or selecting fast-maturing varieties. Always monitor local frost dates to optimize your planting schedule and employ row covers if necessary.

Can I still plant cilantro in May?

Absolutely! If you're in Zone 5b in May, focus on direct sowing your cilantro seeds after May 8, the last frost date. This allows for optimal growth and a fresh harvest throughout the summer months.

Why does my cilantro always bolt?

Cilantro can bolt due to heat or incorrect day lengths. In Maine, ensure your growing schedule aligns with cooler temperatures and consider planting in partial shade to extend the leaf harvest before the herb flowers.

How can I improve the flavor of my cilantro?

The flavor of cilantro can be enhanced by ensuring consistent moisture and avoiding stress from heat. Use well-drained soil and organic compost for nutrients to boost growth and flavor during the cooler seasons.

Is cilantro a perennial in Maine?

Cilantro is an annual herb, meaning it completes its life cycle in one season. However, if allowed to bolt and self-seed, it may return in subsequent seasons, especially if you let some plants flower and drop seeds in your garden.