Home Cannabis Cultivation in Montana

Legal since July 1, 2023. Up to 2 mature plants and 2 seedlings per person — here are the rules for growing at home in Big Sky Country.

Last verified: March 2026

Home Grow Is Legal in Montana

Adults 21 and older can legally grow cannabis at home in Montana. Home cultivation became legal on July 1, 2023, as part of the phased implementation of I-190 and HB 701. Montana's home grow rules balance personal cultivation rights with security and neighborhood considerations.

Plant Limits

Category Recreational (21+) Medical (with card)
Mature/flowering plants per person 2 4
Seedlings per person 2 4
Maximum per household (2+ adults) 4 mature + 4 seedlings Per patient limits apply individually

Growing Requirements

Montana's home cultivation rules include specific security and location requirements:

Locked Enclosed Space

All cannabis plants must be grown in a locked enclosed space. This means:

  • Indoor grow rooms, closets, or tents with a lock
  • Garages or basements that can be secured
  • No outdoor cultivation unless the grow area is fully fenced and locked

The locked enclosure requirement is more restrictive than some states (like Alaska, which simply requires "reasonable precautions"). Montana law is explicit that casual outdoor growing without fencing is not permitted.

No Volatile Solvents

BHO Extraction Is Banned

You cannot use volatile solvents (butane, propane, etc.) to extract concentrates from home-grown cannabis. Butane hash oil (BHO) home extraction is prohibited. Non-volatile extraction methods (ice water hash, rosin press, etc.) are generally permitted for personal use.

Visibility and Access

  • Plants must not be visible from public spaces or neighboring properties
  • Growing areas must prevent unauthorized access, especially by minors
  • Landlords may prohibit cultivation on their property — check your lease

What You Can Do with Home-Grown Cannabis

  • Personal use: Consume what you grow within your home
  • Gift: Adults 21+ can give cannabis to other adults 21+ (no sale or exchange)

What You Cannot Do

  • Sell home-grown cannabis — any sale without a license is illegal
  • Exceed plant limits — up to $250 fine for excess plants
  • Use volatile solvents for extraction
  • Grow in an unlocked or visible location
  • Allow minors access to plants or cannabis products

Tips for Montana Home Growers

  • Climate matters: Montana's short growing season and cold winters make indoor cultivation the most practical option for most growers. Outdoor grows in fenced enclosures are limited to roughly June through early October.
  • Start with seedlings: Your 2 seedling slots let you start new plants before your mature plants finish. Plan rotation for continuous harvests.
  • Living soil: Montana's Living Soil Alliance promotes organic cultivation methods. Many Montana growers embrace craft, soil-based growing over synthetic nutrients.
  • Altitude: Montana's elevation (3,000–5,000+ feet in many areas) affects plant growth. Consider humidity control and UV exposure when planning your indoor setup.

Medical Patient Cultivation

Medical cardholders enjoy double the recreational limits: 4 mature plants + 4 seedlings per patient. The same security requirements apply — locked enclosure, no volatile solvents, no visibility from public spaces. Medical patients may also designate a caregiver to cultivate on their behalf.

Official Sources