How To Grow Northern Lights

If you live in a cold climate, you might think growing certain plants is off limits. Learning how to grow Northern Lights can change that, as this resilient strain is famous for its ability to thrive in cooler conditions. This guide gives you the practical steps to succeed, even with a short season and chilly nights.

Northern Lights is a legendary, mostly indica strain known for its resilience, compact size, and resistance to mold and pests. These traits make it a top choice for colder regions. Its genetics are built for tougher environments, meaning you have a strong partner from the start.

Why It’s Perfect for Cold Climates

This plant has several key advantages for northern gardeners. First, it finishes flowering relatively quickly, often in 7-9 weeks. This allows you to harvest before the deepest frosts of autumn set in.

It also has a robust structure and dense buds that can handle some moisture and cooler temperatures better than many other strains. Its natural mold resistance is a huge benefit in damp, cold fall weather.

Choosing Your Seeds or Clones

Start with quality genetics from a reputable seed bank. Look for the classic Northern Lights #5 or other stable phenotypes. For the fastest finish, choose an autoflowering version. Autoflowers start blooming based on age, not light cycles, which can be a big advantage if your summer light is very long.

Indoor vs. Outdoor in the Cold

Your climate dictates the best approach:

Outdoor: Possible if you have at least 8-10 weeks of reliably mild-to-warm weather (daytime above 60°F/15°C). Use pots to move plants if needed.
Greenhouse: Ideal. It traps heat, extends the season, and protects from frost and heavy rain.
Indoor: Full control. You can grow year-round regardless of outside weather, which is the most guaranteed method.

Germination and Early Seedling Care

Start your seeds indoors, even if you plan to move them outside later. This gives them a strong head start. Use a simple method like placing seeds between moist paper towels in a warm, dark place. They usually sprout in 24-72 hours.

Once the taproot appears, plant it gently in a small pot with light, airy seedling mix. Keep seedlings under a gentle light source (like CFLs or LEDs) for 18-24 hours a day. The room temperature should be comfortably warm, around 70-78°F (21-25°C). Avoid overwatering at this delicate stage.

Vegetative Stage: Building a Strong Plant

This is when your plant grows its leaves and branches. If growing outdoors, time this stage for your warmest months. For photoperiod plants, they need more than 12 hours of light per day to stay in this phase.

Light: Provide plenty of light—full sun outdoors or 18 hours of light per day indoors.
Temperature: Aim for 68-77°F (20-25°C) during the day. Nighttime temps can dip a bit lower.
Feeding: Use a nitrogen-rich fertilizer, but start at half-strength to avoid burning young roots.
Airflow: Ensure good air circulation to strengthen stems and prevent dampness.

The Flowering Stage in Cool Weather

This is the most critical phase in a cold climate. Outdoor plants will naturally begin flowering as summer daylight hours shorten. Indoor growers switch lights to a 12-hours-on, 12-hours-off schedule.

Cool temperatures during flowering can actually enhance the purple hues in the buds and may improve resin production. However, you must avoid frost and excessive dampness.

Monitor Temperatures Closely: If growing outdoors or in a greenhouse, have protective covers like frost cloth ready for cold nights.
Reduce Nitrogen: Switch to a fertilizer higher in phosphorus and potassium to support bud development.
Increase Airflow: Prune some lower leaves to improve air movement around the buds, crucial for preventing mold in cold, still air.
Water Wisely: Water in the morning so the plant uses moisture during the day, avoiding wet roots on cold nights.

Protecting Plants from Frost and Mold

Frost is your biggest enemy. A hard freeze will damage or kill your plant. Mold and bud rot are the second biggest threat in cold, humid conditions.

Use Mobile Pots: Grow in containers so you can move plants into a shed or garage on nights when a frost is forcasted.
Employ a Greenhouse: Even a small plastic hoop house can raise nighttime temperatures by several critical degrees.
Preventative Sprays: Consider organic options like silica sprays to strengthen plant cell walls or compost teas to promote beneficial microbes.
Inspect Daily: Check deep inside buds for any grey or brown fuzz, which is botrytis (bud rot). Remove affected areas immediately with clean tools.

Harvesting at the Right Time

Don’t rush harvest, but don’t wait too long either. Cold, wet fall weather can ruin mature buds quickly. Use a jeweler’s loupe to check trichomes (the tiny resin glands).

When most trichomes have turned from clear to a milky white, with maybe 10-20% turning amber, it’s prime harvest time. If bad weather is coming, it’s better to harvest slightly early than to lose your crop to mold.

Drying and Curing in a Cold Environment

Cold climates often mean high humidity during the typical harvest period. This makes proper drying essential.

Hang whole branches or cut buds in a dark, cool room with a fan for indirect air circulation.
Ideal drying conditions are around 60°F (15°C) and 60% humidity. A dehumidifier may be necessary.
Drying should take 7-14 days. Buds are ready when small stems snap instead of bend.
For curing, place dried buds in airtight jars, filling them ¾ full. Open the jars daily for 10-15 minutes for the first two weeks to release moisture. This slow cure in a cool, dark place greatly improves flavor and smoothness.

Common Challenges and Solutions

Even with a tough plant, you might face issues. Here’s quick fixes for cold-climate problems:

Slow Growth: Caused by cold soil or air. Use black pots to absorb heat, or employ a soil heating mat for seedlings.
Nutrient Lockout: Cold roots can’t absorb nutrients well. Ensure your root zone is warm and avoid overwatering with cold water.
Pests Seeking Shelter: Aphids or spider mites might invade as outside cools. Inspect plants regularly and use insecticidal soap if needed.
Light Deprivation: If fall is very cloudy, indoor supplemental lighting in a greenhouse can help finish flowers.

FAQ: Growing Northern Lights in Cold Climates

What is the lowest temperature Northern Lights can handle?

It can survive brief dips to about 40°F (4°C), but frost (32°F/0°C) will cause significant damage. The ideal range during flowering is 65-80°F (18-26°F) during the day.

Can I grow Northern Lights outdoors in a short summer?

Yes, especially if you use autoflowering seeds. They can go from seed to harvest in as little as 9-10 weeks, making them perfect for very short seasons.

How do I protect my outdoor plants from early fall frost?

Use frost protection blankets, cloches, or cold frames. Moving potted plants against a south-facing wall of your house can also provide radiant heat at night.

Is mold really a big problem with this strain?

Northern Lights is known for good mold resistance, but no plant is immune. In a cold, wet, and dense bud structure, botrytis can still occur. Good airflow and preventative measures are key.

Should I use nutrients differently in the cold?

Yes. Plants metabolize slower in cooler weather. Use nutrients at a slightly reduced strength to prevent salt buildup in the soil, which cold roots struggle with.

Growing in a cold climate requires some extra planning and vigilance, but the rewards are worth it. By choosing the right plant, timing your grow season carefully, and taking simple protective steps, you can achieve a successful harvest. Northern Lights proven toughness makes it one of the most reliable choices for gardeners facing a cool, challenging environment.