Northern Lights is one of the easiest cannabis strains to grow, and that is the main reason it still shows up in gardens 40 years after it left the Pacific Northwest. Plants stay short, flower in about 7 to 9 weeks indoors, and forgive the mistakes that kill fussier genetics. A first-time grower with a 3x3 tent and one LED can finish a crop without much drama.
What is the Northern Lights strain?
Northern Lights is an indica-dominant strain built from Afghani genetics, with a small amount of Thai sativa in some versions. Breeders in Washington state developed it in the 1970s and 1980s, and Dutch seed companies later stabilized numbered lines such as Northern Lights #5. It took Cannabis Cup titles in the 1980s and became a parent to dozens of modern hybrids.
Northern Lights Strain Price: A US Buying Guide
Expect a squat plant with wide, dark green leaves, tight buds, and a sweet, earthy, pine smell. THC content lands between 16 and 21 percent in most lab tests.
Northern Lights grow specs at a glance
- Type: indica-dominant, about 90/10
- THC: 16 to 21 percent
- Flowering time indoors: 7 to 9 weeks
- Outdoor harvest: late September to mid October in the northern hemisphere
- Height indoors: 2 to 4 feet (60 to 120 cm)
- Yield: 300 to 500 grams per square meter indoors in good conditions
- Difficulty: easy, good for beginners
- Best setup: indoor tent, or a sunny spot with wind cover outdoors
How do you grow Northern Lights step by step?
1. Germination and seedlings (week 1)
Plant seeds about half an inch deep in a light starter mix or a damp paper towel, and keep them at 70 to 80°F. Taproots show in 2 to 5 days. Give seedlings 18 hours of light at low intensity, around 200 to 300 PPFD, so they do not stretch.
northern lights strain effects
2. Vegetative stage (weeks 2 to 5)
Northern Lights grows compact, so a short veg period is enough. Most growers flip to flower after 3 to 5 weeks, before plants crowd the tent. Keep the light schedule at 18/6 and raise PPFD to 400 to 600.
Low-stress training works well here. Bend the main stem sideways, tie it down, and the lower branches catch up. Topping once or twice builds an even canopy without adding height. This strain also clones with little effort, so you can keep a mother plant and skip seeds next run.
3. Flowering stage (weeks 6 to 14)
Switch to 12 hours of light and 12 hours of dark. Stretch is mild, often 50 percent or less, so plants seldom outgrow the space. Buds bulk up in weeks 5 through 8 of flower, when water and nutrient demand peaks.
4. Harvest and cure
Check trichomes with a loupe. Chop when most are cloudy with a few amber, which is peak potency. Dry branches for 7 to 10 days at 60 to 65°F and 55 to 60 percent humidity, then jar them and burp the jars each day for 2 to 4 weeks.
How long does Northern Lights take from seed to harvest?
Plan on 10 to 14 weeks from seed. Clones cut that to 8 to 10 weeks because they skip the seedling stage.
- Seedling: 7 to 10 days
- Vegetative: 3 to 5 weeks
- Flowering: 7 to 9 weeks
- Dry and cure: 3 to 6 weeks
Autoflower versions run closer to 8 to 10 weeks from seed. They flower on their own age, not the light schedule, so do not flip them.
What feeding and watering schedule does Northern Lights need?
This strain is not a heavy feeder. Start nutrients at a quarter of the label dose and work up to half, watching leaf tips for burn. Dark green, clawing leaves mean too much nitrogen.
Water when the top inch or two of the medium feels dry, or when the pot feels light. In soil, that lands near every 2 to 3 days in flower. Overwatering is the most common beginner error with this strain.
Temperature, humidity, and the purple fade
Keep daytime temps at 68 to 80°F and nights at 60 to 70°F. Humidity should sit near 60 to 70 percent in veg and drop to 40 to 50 percent in flower. Below 40 percent in late flower lowers the risk of bud rot.
Cooler nights late in flower, around 60°F, can bring out purple and blue tones in the leaves and calyxes. This color change is cosmetic and does not change potency.
Do you need a carbon filter for Northern Lights?
Yes, if you grow indoors and care about smell. Flowering plants give off a sweet, earthy odor that travels through drywall and shared vents. A carbon filter matched to your exhaust fan removes most of it.
Common problems and fixes
- Nutrient burn: flush with plain water and cut the dose in half.
- Stretched seedlings: move the light closer or raise intensity.
- Spider mites: raise humidity, add airflow, and treat leaves on both sides.
- Bud rot: drop humidity, remove affected buds, and improve air movement.
- Slow growth: check root zone temps. Cold feet stall this strain.
Can you grow Northern Lights outdoors?
Yes. Its short flowering window fits cool climates with short summers, and dense indica buds resist mold better than sativa flowers. Pick a spot with 6 or more hours of direct sun and some wind cover.
Rain in October is the main threat. A simple greenhouse cover or a tarp keeps buds dry through the last weeks. Outdoor plants can reach 5 to 6 feet in long seasons, well above their indoor height.
Is Northern Lights a good pick for a first grow?
It is one of the safest choices for a beginner. Short plants fit small tents, the flowering time is fast, and the strain handles temperature swings that stress other cultivars. If you want a forgiving indica that finishes before the weather turns, Northern Lights is hard to beat.