When To Plant Herbs In Maine

When to plant herbs in Maine depends on your hardiness zone, your specific herbs, and your willingness to work around the state’s famously short growing season.
 
If you’ve been wondering when to plant herbs in Maine, the short answer is that you can start cold-hardy herbs as early as late April, while tender herbs need to wait until after the last frost, which is usually around Memorial Day.
 
Maine’s climate is a mix of USDA zones 3 through 6, so your exact planting window shifts depending on whether you’re near the coast, inland, or up in Aroostook County.
 
In this post, we’ll walk you through when to plant herbs in Maine for every type of herb, plus tips on starting seeds indoors, hardening off, and extending your harvest into the fall.
 
Let’s dig into the details so you can get your herb garden growing with confidence.
 

When to Plant Herbs in Maine: The Core Window

The most reliable answer to when to plant herbs in Maine is to use your last frost date as your anchor point.
 
For most of southern and coastal Maine, that date falls between May 15 and May 25.
 
Inland and northern regions, expect the last frost as late as June 1 or even mid-June in the coldest spots.
 
Once you know that date, you can count backward for indoor seeding and count forward for direct sowing.
 
Here’s the breakdown of when to plant herbs in Maine by category.
 

1. Cold-Hardy Herbs: Late April to Early May

When to plant herbs in Maine that can handle a little frost?
 
Start with perennials like thyme, sage, oregano, mint, and chives, as these can go in the ground as soon as the soil is workable.
 
This is usually late April in southern Maine and early May farther north.
 
These herbs tolerate light frosts, so you don’t have to wait for the danger to pass completely.
 
Direct sow seeds or transplant seedlings, and you’ll be rewarded with early growth.
 

2. Semi-Hardy Herbs: Early to Mid-May

Herbs like cilantro, dill, and parsley handle cool soil but can be damaged by a hard freeze.
 
When to plant herbs in Maine for these varieties?
 
Aim for early to mid-May, as soon as the soil temperature reaches about 50°F.
 
You can even plant these in succession every two to three weeks for a continuous harvest.
 
Just keep an eye on the forecast and cover them with row cloth if a late frost sneaks in.
 

3. Tender Herbs: After Memorial Day

Basil, rosemary, and tender annuals like lemongrass absolutely cannot handle frost.
 
When to plant herbs in Maine for these heat-lovers?
 
Wait until the nighttime temperatures stay consistently above 50°F, usually after May 30.
 
In northern Maine, you might push that to mid-June.
 
Planting them too early leads to stunted growth or death, so patience is key here.
 

Starting Herbs Indoors in Maine

If you want to get a head start on when to plant herbs in Maine, indoor seeding is your best friend.
 
Begin seeds indoors about six to eight weeks before your last frost date.
 
For southern Maine, that means starting basil and rosemary indoors in early April.
 
For northern Maine, start them in mid-April.
 
Use a seed tray with a heat mat and grow light for the best germination.
 

1. Hardening Off Is Essential

Moving seedlings directly from indoors to the garden is a sure way to shock them.
 
About a week before transplanting, set them outside for a few hours each day.
 
Gradually increase their time outside and their exposure to sun and wind.
 
This is a critical step in when to plant herbs in Maine because our spring weather is so variable.
 

2. Use Cold Frames or Low Tunnels

To stretch when to plant herbs in Maine earlier, build a cold frame or low tunnel over your garden bed.
 
These simple structures trap heat and protect young herbs from frost.
 
With a cold frame, you can plant hardy herbs two to three weeks earlier than usual.
 
Tender herbs can also go in a week or two ahead of the last frost date if they’re protected.
 

Best Herbs to Grow in Maine’s Climate

Knowing when to plant herbs in Maine is only half the battle, you also want to pick herbs that thrive here.
 
Maine’s cool nights and moderate summer days are perfect for many herbs.
 

1. Perennial Favorites

Chives, thyme, sage, and oregano are incredibly tough and return every year.
 
Plant these once, and you’ll harvest them for a decade.
 
Mint also thrives, but always plant it in a container or it will take over your whole garden.
 

2. Annual Herbs That Love the Cool

Cilantro, dill, and parsley prefer cooler temperatures and will bolt (go to seed) in hot summer heat.
 
Plant these early, and succession sow every few weeks.
 
You’ll get fresh leaves from spring through early summer, then again in the fall.
 

3. Tender Annuals Worth the Effort

Basil is the crown jewel of summer herbs, but it needs consistent warmth.
 
Rosemary can also be grown as an annual in Maine, though it takes a long time to mature.
 
Buy transplants for these instead of seeds to save time.
 

Extending the Herb Growing Season in Maine

The question of when to plant herbs in Maine doesn’t end in May, because you can keep the harvest going well into fall.
 
As summer winds down, you can do a second planting of cold-hardy herbs in late July or early August.
 
This “fall crop” will mature as the weather cools, giving you fresh herbs until Thanksgiving in many areas.
 
Protect them with a cold frame or cloche as nights get frosty.
 

1. Overwintering Hardy Herbs

Perennial herbs like thyme and sage can handle Maine winters, but they appreciate a layer of mulch.
 
Apply straw or leaves around the base after the ground freezes to protect roots from heaving.
 
This way, your herbs come back stronger the next spring.
 

2. Bringing Herbs Indoors

Tender herbs like basil and rosemary can be potted up and moved indoors before frost.
 
Place them in a sunny south-facing window or under a grow light.
 
While they won’t grow as vigorously indoors, you’ll still get fresh leaves through winter.
 

So, When to Plant Herbs in Maine?

When to plant herbs in Maine ultimately comes down to your specific microclimate, but the general rule is simple: hardy herbs in late April, semi-hardy herbs in early May, and tender herbs after the last frost in late May or early June.
 
When to plant herbs in Maine also involves starting seeds indoors six to eight weeks ahead, hardening off seedlings, and using protective structures to stretch the season.
 
By following these timelines, you’ll have a thriving herb garden that produces from spring through fall.
 
Whether you’re a seasoned gardener or a beginner, timing is everything, so mark your calendar and get ready to plant.
 
Your herbs will thank you, and so will your kitchen.