For indoor growing, the strains our guides rate easiest are Northern Lights and Blue Dream, with White Widow and Granddaddy Purple close behind; OG Kush and Girl Scout Cookies reward experienced growers but are rated moderate to difficult. The right pick depends on your height limit, your patience and your experience, and the strain name on a seed pack does not guarantee identical plants. Plan the grow before you choose the seed.
Indoor growers control light, temperature and humidity, which opens up strains that struggle in the wet Pacific Northwest autumn. It also adds new constraints, mainly height and the ability to flower on a fixed light schedule. Cannabis is a short-day plant, so indoor growers switch the light cycle to 12 hours of light and 12 of dark to start flowering (Backer et al., Frontiers in Plant Science, 2019). Any cultivar that responds to that schedule will work indoors; what separates them is size, difficulty and flowering time.
Growing at Home: Washington and Oregon Law
Home growing is legal for adults 21 and older in Oregon, up to 4 plants per household, kept out of public view; see the statute (ORS 475C.305) and our Oregon marijuana laws guide. In Washington, home growing is legal only for registered medical patients. Under RCW 69.51A.210, a patient entered in the state medical cannabis authorization database may grow up to six plants by default, or up to fifteen if a health care professional recommends it. Adults who buy only at retail stores may not grow. See our Washington marijuana laws guide. Cannabis remains illegal under federal law, and local rules and landlord or HOA restrictions can add limits.
Top Strains to Grow Indoors at a Glance
| Strain | Type | Difficulty | Flowering | Yield | Height |
|---|---|---|---|---|---|
| Northern Lights | Indica-dominant | Easy | 7 to 9 weeks | Medium to high | Short to medium, bushy |
| Blue Dream | Sativa-dominant hybrid | Easy to moderate | 9 to 10 weeks | High | Tall; needs topping and training |
| White Widow | Balanced hybrid | Moderate | About 8 to 9 weeks | Medium to high | Medium |
| Granddaddy Purple | Indica-dominant hybrid | Moderate | 8 to 11 weeks | Medium to high | Short to medium |
| Purple Kush | Pure indica | Moderate | 8 to 9 weeks | Medium | Short to medium |
| OG Kush | Balanced hybrid | Moderate to difficult | 8 to 9 weeks | Low to medium | Medium; stretches a bit |
| Girl Scout Cookies | Indica-dominant hybrid | Moderate to difficult | 9 to 10 weeks | Low to medium | Medium to tall; stretches in early flower |
Source: the “Growing” section of each strain guide on this site. These are general descriptions, and plants vary by seed company and by cut.
What Makes a Strain Good for Indoor Growing
Size and stretch
Indoor space has a ceiling. Plants that stay short and bushy are easier to keep under lights, while tall cultivars need topping and a screen. Our guide to Blue Dream says it grows tall and stretches in flower, so indoor growers usually top it and use a screen or trellis. See scrogging and trellising for how.
Difficulty
Dense, resinous flowers can invite mold, and some cuts are fussy about feeding. Our OG Kush guide says dense buds raise mold risk and describes the plant as fussy with modest yields. Girl Scout Cookies gets the same difficulty rating. If this is your first grow, the easier rows above are the better start.
Flowering time
Shorter flowering means a faster harvest. Northern Lights, at 7 to 9 weeks, is the quickest in this list, and the guide credits it with helping set the standard for a fast-flowering, resinous indoor plant. A longer-flowering strain like Blue Dream, at 9 to 10 weeks, needs more room and patience but is rated high-yielding.
Climate control
Indoors you have to manage the room. A 2025 review puts optimal growth at 25 to 35 degrees Celsius, and in one experiment high humidity of 78 to 98% delayed flowering and lowered cannabinoid levels. The same review gives recommended relative humidity of 40 to 60% during flowering (Corredor-Perilla et al., Frontiers in Plant Science, 2025). Dense-budded strains make humidity control more important.
What a Strain Name Does and Does Not Tell You
Strain names are marketing as much as genetics. A 2019 meta-analysis noted that variety names do not always correspond to genotype (Backer et al., 2019). A 2022 study of nearly 90,000 lab-tested flower samples from six US states found that strain names were more consistent than the labels indica, sativa and hybrid, but still far from ideal (Smith et al., PLoS One, 2022). Our Purple Kush guide makes the same point for seeds: companies have released several versions, so buying the name does not guarantee the original genetics. For a closer look at the labels, see our guide to the difference between sativa and indica.
Practical advice follows: buy from a seller who lists the cross and breeder, read the grower notes, and expect plants from different companies to behave differently.
How to Choose
- First grow: Northern Lights, for its easy rating, short stature and quick finish.
- Want maximum yield and have headroom: Blue Dream, with training.
- Tent with low ceiling: Granddaddy Purple or Purple Kush, both rated short to medium.
- Experienced, chasing flavor and potency: OG Kush or Girl Scout Cookies, accepting lower yields.
Remember that your plant count is the limit that matters. Oregon allows 4 per household, so a higher-yielding cultivar can be worth more than a rare one. For the whole process, start with basic marijuana growing, then learn trimming. Buying instead? Browse licensed shops in Washington and Oregon.
Top Strains to Grow Indoors FAQ
What is the easiest strain to grow indoors?
Our guides rate Northern Lights as easy, with a short, bushy plant and a 7 to 9 week flowering time. Blue Dream is rated easy to moderate but grows tall.
Which strain yields the most indoors?
Blue Dream is rated high yield in our guide. Yields depend on your lights, space and training, so treat the rating as a guide, not a promise.
How long does indoor flowering take?
From 7 to 9 weeks for Northern Lights up to 9 to 10 weeks for Blue Dream and Girl Scout Cookies, counted from the switch to 12/12 light.
Do indoor strains need to be indica?
No. Any strain that flowers on a 12/12 light schedule works indoors. Height and flowering time matter more than the indica or sativa label.
Can I grow these strains in Washington?
Only if you are a registered medical patient. Adults in Oregon may grow up to 4 plants per household. See the laws section above.
Where can I buy seeds?
We do not sell or recommend seed vendors. Check your state’s rules and buy from a seller that names the breeder and cross.
For adults 21+ in legal states. General information, not medical advice.
