Montana voters approved adult use cannabis in 2020, and lawmakers shaped the details in 2021 with House Bill 701. Home growing is legal, but the count is small and split between mature plants and seedlings. Montana’s short season and cold nights at elevation make planning important. This guide explains the law and how to grow within it in 2027. It is general information for adults 21 and older, not legal advice.

The plant count

Each adult 21 or older may grow up to two mature plants and two seedlings. A residence may not contain more than four mature plants and four seedlings in total, no matter how many adults live there.

Who	Mature plants	Seedlings
Per adult	2	2
Per residence	4	4

The difference between a mature plant and a seedling matters. Treat a plant that is flowering as mature. Keep a simple log so you know which stage each plant is in.

Where plants can be grown

Plants must be grown in a locked space that is not visible from a public place without binoculars or aircraft. A locked greenhouse, locked tent or locked room works. Keep plants away from anyone under 21.

Possession

Adults may possess up to one ounce of flower and up to eight grams of concentrate in public. Cannabis harvested from your plants may be kept at the place where it was grown, stored securely.

Gifting and selling

Adults may give cannabis to another adult 21 or older within the limits without payment. Selling home grown cannabis, seedlings or seeds without a license is illegal.

Medical patients

Montana’s medical marijuana program has its own rules, including the option for registered patients to grow under different limits. If you are a registered patient, check the Department of Revenue’s medical program page for your current count.

Renters

Landlords can prohibit cultivation. Ask in writing.

Growing in Montana

Montana’s growing season is short and nights can be cold even in July at elevation.

• Start indoors. Begin seedlings in April under lights. Remember they count toward your seedling limit.
• Move out after frost. Late May or early June is typical in many valleys.
• Pick fast finishers. Strains that finish by mid September avoid most frost. autoflower seeds are another option.
• Use a greenhouse. It traps heat on cold nights and keeps early snow off plants.
• Protect against wind. Plains wind can snap branches. Stake plants and use trellis netting.

Our guide on when to harvest outdoor cannabis helps when frost threatens.

Indoor growing

Many Montanans grow indoors in a locked tent. Winter air is cold and dry, so plan for heat and some added humidity. See our complete grow tent setup guide for basics and low stress training to make the most of two mature plants.

What to watch in 2027

Montana’s Legislature meets in odd years, so the 2027 session will consider cannabis bills. Past sessions focused on tax revenue, licensing and local option rules. Check the Department of Revenue Cannabis Control Division before you plant.

Seedling versus mature plant

Montana separates mature plants from seedlings, so stage tracking matters more than in states with a single total. A practical approach is to treat any plant that shows flowers as mature. Keep seedlings small and young until a mature slot opens. If a seedling starts flowering early, it may count as mature, which can push you over the limit.

Odor and neighbors

Montana towns can apply nuisance rules to strong odors. Use carbon filters indoors and keep outdoor plants inside a locked structure away from property lines.

Tribal lands

Montana has several reservations with their own laws. State home grow rules may not apply on tribal land. Check which laws apply where you live.

How Montana compares with its neighbors

Idaho, Wyoming, North Dakota and South Dakota do not allow adult home grow. Do not carry plants or cannabis across state lines.

Montana’s short season, east and west

Montana growers face one of the shortest outdoor seasons among home grow states. West of the Divide, Missoula and the Flathead Valley have somewhat milder conditions but still see frost into late May and again by mid September. Bozeman, Butte and Helena sit higher and can freeze in nearly any month. The eastern plains around Billings warm faster in summer but bring hail, strong wind and sudden cold fronts.

Because of that, many Montanans grow indoors or use autoflowers outdoors. Photoperiod plants started outside often run out of time before buds finish. A greenhouse or hoop house helps, but it must still keep plants out of public view and inaccessible to anyone under 21. Our guide on when to plant cannabis seeds outdoors explains how to work backward from your first fall frost.

Hail, wind and wildlife

Hail can shred a flowering plant in minutes. Keep a cover ready or grow in containers you can move under shelter. Deer and elk will browse unprotected plants in rural areas, so a sturdy fence serves both security and garden protection. Wildfire smoke in late summer can coat leaves with ash, so gently rinse plants after heavy smoke and before buds are fully formed.

Indoor tips for long winters

Montana homes get very dry in winter. A small humidifier helps seedlings, while a dehumidifier matters more in flower. Insulated tents reduce heat loss in cold basements.

Key takeaways

• Two mature plants and two seedlings per adult.
• No more than four mature and four seedlings per residence.
• Locked space not visible from public.
• One ounce of flower in public.
• Plan around a short, cold season.

Our Montana seed page highlights fast finishing strains.

Grow legally and responsibly

Home cultivation is only legal in some states, and each state sets its own plant limits, locking rules and rules about whether plants can be visible from a public place. You must be 21 or older to buy seeds from Kind Seed Co, and you should grow only where your state and city allow it. Check your state rules in our guide to the legal requirements for growing weed plants in your state before you plant. Federal treatment of cannabis seeds is also changing, so read our December 11 2026 seed rule explainer before you order. Keep plants and harvested flower locked away from children, pets and visitors, and never drive after using cannabis. This article is general information about gardening. It is not legal advice and it is not medical advice.

Frequently asked questions

How many plants can I grow in Montana?

Each adult may grow two mature plants and two seedlings, with no more than four of each per residence.

How much cannabis can I carry in Montana?

Up to one ounce of flower and eight grams of concentrate.

Do Montana grows need to be locked?

Yes. Plants must be in a locked space not visible from a public place.

When does the Montana Legislature meet?

In odd numbered years, so the next session is 2027.

Ready to start

Browse the full range in the Kind Seed Co shop or go straight to marijuana seeds montana. Kind Seed Co sells only to adults 21 and older. Always follow the home grow laws where you live.