Northern lights cannabis strains need specific light cycles during their flowering stage to reach their full potential. If you are wondering how to grow northern lights successfully, you have come to the right place. This guide covers everything from seed to harvest, with clear steps and practical advice for both beginners and experienced growers.
Northern Lights is one of the most famous indica strains in the world. It is known for its resilience, compact growth, and resinous buds. Growing it at home can be very rewarding, but you need to follow a few key rules. Let’s get started.
Understanding Northern Lights Genetics
Northern Lights is a pure indica strain, though some phenotypes show slight sativa traits. It originated in the Pacific Northwest and was later stabilized in the Netherlands. The plant stays short and bushy, making it ideal for indoor grows with limited space.
It has a fast flowering time of 45 to 55 days. The buds are dense and covered in trichomes. The aroma is earthy, piney, and slightly sweet. Because of its genetics, it is forgiving of small mistakes, which makes it great for first-time growers.
Key Characteristics Of Northern Lights
- Height: 90–130 cm indoors, 150–200 cm outdoors
- Flowering time: 7–8 weeks
- Yield: 400–500 g/m² indoors, up to 600 g per plant outdoors
- THC content: 15–20%
- Difficulty: Easy to moderate
How To Grow Northern Lights
Now we get into the main part of the guide. This section covers every stage of growth, from germination to harvest. Follow these steps closely for the best results.
Step 1: Germinate Your Seeds
Start with high-quality Northern Lights seeds from a reputable seed bank. Use the paper towel method or plant directly into a starter cube. Keep the temperature at 21–25°C and humidity around 70%. Seeds usually sprout in 2–5 days.
Do not overwater at this stage. Moisture is good, but soaking wet seeds can rot. Once you see a taproot, transfer the seed to a small pot with light soil.
Step 2: Choose The Right Growing Medium
Northern Lights grows well in soil, coco coir, or hydroponics. For beginners, organic soil is the safest option. It buffers pH and provides natural nutrients. Use a mix with good drainage, like 70% soil and 30% perlite.
If you want faster growth, try coco coir. It holds oxygen well and allows for more control over nutrients. Just remember to buffer the coco with calcium and magnesium before use.
Step 3: Provide Proper Lighting
During the vegetative stage, give your plants 18–20 hours of light per day. Use LED, HPS, or CFL lights. Keep the light 18–24 inches above the canopy to prevent light burn. Northern Lights responds well to high light intensity, but avoid heat stress.
When you switch to flowering, change the light cycle to 12 hours on and 12 hours off. This is the most critical step. Any light leaks during the dark period can cause hermaphroditism or slow bud development.
Step 4: Control Temperature And Humidity
Northern Lights prefers a warm environment. Keep daytime temps at 22–28°C and nighttime temps at 18–22°C. Humidity should be 60–70% during veg and 40–50% during flower. High humidity in late flower can lead to bud rot.
Use a small fan to circulate air. This strengthens stems and prevents mold. If your grow room is too dry, add a humidifier. If too humid, use a dehumidifier or increase exhaust.
Step 5: Water And Nutrients
Water your plants when the top inch of soil feels dry. For soil grows, water until you see runoff, then wait for the pot to feel light again. Overwatering is a common mistake. Northern Lights does not like soggy roots.
Use a balanced fertilizer during veg (like 3-1-2 NPK). Switch to a bloom formula with higher phosphorus and potassium during flower. Reduce nitrogen in late flower to improve bud quality. Always pH your water to 6.0–6.5 for soil or 5.5–6.0 for coco.
Step 6: Train Your Plants
Northern Lights has a naturally bushy structure, but training helps increase yields. Use low-stress training (LST) by bending branches down with soft ties. This exposes more bud sites to light. You can also try topping once or twice during veg to create multiple colas.
Avoid high-stress training like supercropping unless you have experience. Northern Lights recovers well from topping, but too much stress can slow growth.
Step 7: Manage The Flowering Stage
After switching to 12/12 light, your plants will stretch for 2–3 weeks. Keep the light close enough to prevent stretching, but not so close that it bleaches the buds. Northern Lights usually stops stretching after week 3.
Check for male plants or hermies. Remove them immediately to avoid pollination. Female plants will start forming white pistils around week 2–3. By week 5, buds should be dense and sticky.
Step 8: Flush Before Harvest
About 1–2 weeks before harvest, stop giving nutrients. Flush the plants with plain pH-balanced water. This removes excess salts and improves the flavor of the final product. For soil, use 3 times the pot volume in water. For coco, use 2 times.
Watch the leaves. They will turn yellow as the plant uses up stored nutrients. This is normal and desired.
Step 9: Harvest And Dry
Harvest when 70–90% of the pistils have turned brown and curled in. Use a jeweler’s loupe to check trichomes. Milky white trichomes give a head high, while amber trichomes give a more sedative effect. For Northern Lights, aim for 10–20% amber.
Cut the branches and hang them upside down in a dark room at 18–21°C with 50–60% humidity. Drying takes 7–14 days. Do not rush this step. Proper drying preserves terpenes and prevents mold.
Step 10: Cure Your Buds
After drying, trim the buds and place them in glass jars. Fill jars 75% full. Open the lids for 10–15 minutes twice a day for the first week. Then reduce to once a day for the next two weeks. Cure for at least 2–4 weeks for best flavor and potency.
Longer curing (2–3 months) makes the smoke smoother and the aroma more complex. Store jars in a cool, dark place.
Common Problems And Solutions
Even though Northern Lights is hardy, you may face some issues. Here are the most common ones and how to fix them.
Nutrient Burn
If leaf tips turn brown and crispy, you are feeding too much. Flush with plain water and reduce nutrient strength by half.
Light Burn
Leaves near the light turn yellow or white. Raise the light or increase the distance. LED lights should be at least 18 inches away.
Bud Rot
Gray mold inside buds, usually in high humidity. Improve airflow and lower humidity to 40–50%. Remove affected buds immediately.
Spider Mites
Small white spots on leaves and fine webbing. Use neem oil or insecticidal soap. Keep humidity above 50% to discourage mites.
Outdoor Growing Tips
Northern Lights performs well outdoors in warm, sunny climates. Plant after the last frost in a spot with full sun. Use large pots or plant directly in the ground. The plant stays short, so it is easy to hide from neighbors.
Harvest time is usually late September to early October in the Northern Hemisphere. Watch for rain and mold in late flower. A greenhouse can extend the growing season and protect against pests.
Yield Optimization
To get the most from your Northern Lights plants, focus on these factors:
- Use a high-quality light with full spectrum
- Maintain consistent temperature and humidity
- Train plants to create an even canopy
- Provide adequate airflow with oscillating fans
- Monitor pH and EC levels weekly
With proper care, indoor yields can reach 500 g/m². Outdoor plants can produce up to 600 g each. The key is patience and attention to detail.
Frequently Asked Questions
How long does it take to grow Northern Lights from seed?
From seed to harvest, it takes about 10–12 weeks. Vegetative stage lasts 3–4 weeks, and flowering takes 7–8 weeks.
Is Northern Lights good for beginners?
Yes. It is one of the easiest strains to grow. It resists mold and pests well and tolerates small mistakes in watering or nutrients.
Can I grow Northern Lights in a small tent?
Absolutely. It stays short and bushy, making it perfect for 2×2 or 3×3 foot tents. Use LST to keep the canopy even.
What is the best light cycle for Northern Lights?
18/6 during veg and 12/12 during flower. Some growers use 20/4 for veg, but 18/6 is standard and gives plants a rest period.
How do I know when Northern Lights is ready to harvest?
Check the trichomes with a magnifier. When most are milky white and some are amber, it is time. Also, pistils should be mostly brown.
Final Thoughts
Growing Northern Lights is a rewarding experience for any cannabis cultivator. Its resilience, fast flowering, and high-quality buds make it a top choice. Follow the steps in this guide, and you will get a great harvest.
Remember to monitor your plants daily. Small adjustments in light, water, or nutrients can make a big difference. Keep a grow journal to track what works best for your setup.
With practice, you will master the art of growing this classic strain. Enjoy the process and the results. Happy growing.