A Guide to Colorado Home Grow Laws
Last updated: March 2026
Colorado home grow laws allow adults 21 and older to cultivate up to six plants per person, with no more than three flowering at any one time and a twelve-plant household maximum. Colorado was one of the first two states to legalize recreational cannabis, passing Amendment 64 in 2012. There is one rule that surprises many new growers: Colorado requires all cultivation to take place indoors in a locked, enclosed space. Outdoor growing is not permitted under state law. Here’s what the rules require.
Disclaimer: Cannabis laws change. This post reflects our best understanding of Colorado law as of early 2026. Local rules vary significantly — always verify current regulations with the Colorado Marijuana Enforcement Division and your local municipality before you grow.
Table of Contents
- The Short Version
- Who Can Grow
- How Many Plants
- Where You Can Grow
- Security Requirements
- No Outdoor Growing
- Local Ordinances
- Penalties for Going Over the Limit
- Ready to Start Growing?
- Frequently Asked Questions
The Short Version
| Rule | Detail |
|---|---|
| Legal for adults? | Yes, 21 and older |
| Plant limit | 6 per adult, 12 per household |
| Mature plant limit | 3 flowering plants at any one time |
| Indoor growing | Required — outdoor not permitted |
| Outdoor growing | Not permitted under state law |
| Must be locked? | Yes — locked, enclosed area required |
| Visible from public? | Not permitted |
| Plant tagging required? | No |
| Landlord restrictions? | Yes, landlords can prohibit cultivation |
Who Can Grow
Any Colorado resident 21 years of age or older can grow cannabis at home. Amendment 64 passed in November 2012, making Colorado one of the first two states in the country to legalize recreational cannabis. No permit or medical card is required for recreational home cultivation.
Colorado also has a medical cannabis program, active since 2000. Medical patients may qualify for higher plant counts under different rules. This post covers recreational home cultivation.
If you rent, check your lease and get written consent from your landlord. Some municipalities — including Colorado Springs — require written owner consent before cultivation can take place.
How Many Plants
Colorado allows up to six plants per adult, with a household cap of twelve regardless of how many adults live there. Of your six plants, no more than three can be flowering at any one time. Plants in vegetative growth, clone stage, or seedling stage do not count against the three-flowering limit.
Colorado law defines a plant as any cannabis plant in a growing medium that is more than four inches wide or four inches tall, or any flowering plant regardless of size. A clone or cutting under four inches does not count toward your plant total.
The three-flowering limit makes Colorado’s rules similar to Alaska’s in structure, but with the added constraint of indoor-only cultivation.
Where You Can Grow
Colorado requires all home cultivation to take place indoors in a locked, enclosed area. The plants cannot be outside. This is one of the most notable differences between Colorado and most other legalized states — outdoor growing is explicitly prohibited under state law regardless of whether plants would be visible from public view.
Cultivation must take place at your primary residence only.
Security Requirements
Plants must be in a locked, enclosed space that cannot be openly viewed. At homes where minors live, the grow area must be in a separate locked space that minors cannot access. At homes without minors, extra precautions are still required to ensure that any visiting youth cannot access the plants.
Some local jurisdictions add further requirements. Colorado Springs, for example, requires a ventilation and filtration system that prevents odors from being detectable outside the residence, and limits grow space to 150 square feet for single-family homes and 75 square feet for other dwelling types.
No Outdoor Growing
Colorado’s prohibition on outdoor cultivation is worth emphasizing because it runs counter to what many new growers assume. Even in a fully fenced, private backyard with no public visibility, growing cannabis outdoors is not legal under Colorado state law.
The practical reason many growers cite is that Colorado’s low humidity, intense sunshine, and variable weather create real challenges for outdoor cannabis — but the prohibition is legal, not climatic. Indoor growing in Colorado is straightforward and the state’s climate actually makes ventilation and humidity management easier than in many other states.
Local Ordinances
Colorado municipalities can impose additional restrictions on home cultivation beyond state law. Notable examples:
Denver caps household grows at twelve plants even if three or more adults live in the residence, mirroring the state household cap but removing any per-person scaling beyond two adults.
Colorado Springs adds square footage limits (150 sq ft for single-family homes, 75 sq ft for other dwelling types), requires odor mitigation systems, and requires written consent from the property owner.
Other cities and counties may have their own rules. Check your local ordinances before you set up a grow.
Penalties for Going Over the Limit
Growing more than twelve plants at a residence — the household cap — is a level 1 drug petty offense for a first violation, punishable by a fine up to $1,000. A subsequent violation with up to twenty-four plants is a level 1 drug misdemeanor carrying six to eighteen months in county jail and fines of $500 to $5,000. Growing more than twenty-four plants on a subsequent offense is a class 3 drug felony with two to four years in prison and fines up to $500,000.
Ready to Start Growing?
Colorado’s indoor-only requirement means your setup, lighting, and environment are entirely in your hands — which is actually an advantage for consistent results. Six plants per adult with a well-designed indoor space can produce a meaningful personal supply. Browse our strain catalog to find varieties suited to indoor cultivation, and visit the grow guide when you’re ready to get started.
Browse Our Strain Catalog | How to Grow Guide | USDA Zone Map
Frequently Asked Questions
How many cannabis plants can I grow in Colorado?
Six plants per adult, with a household cap of twelve. No more than three of your plants can be flowering at any one time. The household cap applies regardless of how many adults live in the residence.
Can I grow cannabis outside in Colorado?
No. Colorado state law requires all home cultivation to take place indoors in a locked, enclosed space. Outdoor growing is not permitted even in a private, fenced backyard.
What is the three-flowering-plant rule in Colorado?
Of your six allowed plants, no more than three can be in the flowering stage at any one time. Plants in vegetative growth, clone stage, or seedling stage do not count against the three-flowering limit. A clone or cutting under four inches in any direction does not count toward your plant total at all.
Do I need a permit to grow cannabis at home in Colorado?
No permit is required at the state level. However, some municipalities require written consent from your property owner. Check your local rules before you grow.
Can my landlord stop me from growing in Colorado?
Yes. Landlords can prohibit cannabis cultivation in rental agreements. Some municipalities also require written owner consent as a condition of legal cultivation.
Does Denver have different rules than the rest of Colorado?
Denver caps household grows at twelve plants even if more than two adults live in the residence, which removes any benefit of having three or more adult growers in a single home. Colorado Springs adds square footage limits and odor mitigation requirements. Always check your city or county rules.
What are the penalties for growing too many plants in Colorado?
Growing more than twelve plants is a level 1 drug petty offense for a first violation, with fines up to $1,000. Subsequent violations with up to twenty-four plants are a misdemeanor. More than twenty-four plants on a subsequent offense is a class 3 drug felony.
Is Colorado a good state for indoor cannabis growing?
Yes. Colorado’s low humidity makes controlling moisture in an indoor grow easier than in many other states, and the dry climate reduces the risk of mold and mildew. The state has a mature, well-established home grow culture going back to 2012.
Where can I buy cannabis seeds in Colorado?
Triangle Seeds ships feminized cannabis seeds to Colorado and all 50 states. Browse our seed catalog to find the right genetics for your grow.
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