Is It Legal to Grow Cannabis at Home in Hawaii? (2026 Rules)

Jurisdiction: Hawaii  |  Last verified: September 4, 2026  |  Program: Hawaii Medical Cannabis Registry Program

Quick answer: Hawaii does not have a general adult-use home-grow allowance. A registered qualifying patient or the patient’s reported primary caregiver may grow medical cannabis when the grow site and authorized grower are identified on the patient’s valid 329 registration card. The patient and caregiver may jointly possess no more than 10 cannabis plants, whether mature or immature.

Out-of-state registration is different: Under HRS §329-121, qualifying out-of-state patients and their caregivers are not authorized to cultivate through that registration. Their permitted supply excludes live plants; a temporary out-of-state 329 card does not create a home-grow allowance.

Hawaii medical home-grow rules in plain language

• Who may grow: the registered qualifying patient or a registered primary caregiver identified on the patient’s 329 card. The general rule is one primary caregiver per patient. For a minor patient, the Department of Health may register up to two, provided both are that minor’s parent, guardian or legal custodian. This exception does not increase the patient’s shared plant or usable-cannabis limit.
• Plant limit: 10 cannabis plants total, whether immature or mature, jointly between the patient and caregiver.
• Usable cannabis limit: four ounces jointly between the patient and caregiver.
• Grow site: only the one location identified on the 329 card.
• Allowed locations: the patient’s residence, the caregiver’s residence, or another site owned or controlled by the patient or caregiver.
• Plant tags: each plant must carry a legible tag showing the 329 registration number and expiration date.
• Handling: only the registered patient and the reported primary caregiver may handle the patient’s plants or usable cannabis.

The 10-plant limit is shared

Hawaii defines the patient’s “adequate supply” as no more than 10 plants and four ounces of usable cannabis at one time. Those amounts are jointly possessed between the qualifying patient and primary caregiver. Naming a caregiver does not double the patient’s plant count.

Only the registered grow site is covered

The home-grow protection follows the location printed on the patient’s valid 329 card. Moving the plants to an unregistered residence or having an unlisted person water, harvest or care for them can fall outside the registered patient-caregiver relationship.

Before you start

1. Confirm the 329 card is current. Check its expiration date and the patient information.
2. Verify the grow site. The exact cultivation location must appear on the card.
3. Verify the grower. If a caregiver will cultivate, that caregiver must be the person listed on the card.
4. Tag every plant. Use the required registration number and expiration date.
5. Count all stages together. Seedlings, immature plants and mature plants all count toward the shared 10-plant maximum.

Official Hawaii sources

• Hawaii Department of Health: Growing medical cannabis
• Hawaii Revised Statutes §329-121: Definitions and adequate supply
• Hawaii Revised Statutes §329-123(b)–(c): Caregiver registration and minor-patient exception

Ready to learn the cultivation side?

After the patient, grower and grow site are correctly registered, use the HWGrow complete beginner guide for a practical seed-to-harvest workflow.

Compare Hawaii with the HWGrow U.S. cannabis home-grow law guide.

Hawaii home-grow FAQ

How many medical cannabis plants may a Hawaii patient grow?

The patient and primary caregiver may jointly possess no more than 10 plants total, whether the plants are mature or immature.

Can a Hawaii medical cannabis caregiver grow for a patient?

Yes, when the caregiver and the registered grow-site location are identified on the patient’s valid 329 registration card.

Do Hawaii medical cannabis plants need tags?

Yes. Each plant must have a legible tag showing the patient’s 329 registration number and expiration date.