Northern Lights Seeds

How to Control Temperature and Humidity for Northern Lights?

Alright, so you’re growing Northern Lights — classic choice. That strain’s like the old soul of cannabis. Calm, sturdy, forgiving. But don’t let that fool you into thinking you can just toss it in a closet and hope for the best. Temperature and humidity? Yeah, they matter. A lot. Screw those up and you’ll end up with moldy buds or stunted growth. Or both. It’s not rocket science, but it’s not a walk in the park either.

Let’s talk temp first. During veg, keep it warm—like 70 to 85°F (21 to 29°C). Not sauna-hot, but cozy. Plants are like people, kinda. They don’t like freezing their leaves off at night, and they sure as hell don’t want to bake under a 1000W light with no airflow. At night, let it drop a bit—maybe 10 degrees cooler. That dip helps with respiration and keeps things from getting too stagnant. But don’t go overboard. You’re not simulating the Arctic.

Flowering? Drop it down a notch. 65 to 80°F (18 to 27°C) is your sweet spot. Cooler temps help bring out those purples and frosty trichomes Northern Lights is known for. Plus, it slows down mold. Mold is the enemy. Mold is the devil. Mold will ruin your life.

Humidity’s a whole different beast. In veg, you want it higher—like 50 to 70%. Young plants are thirsty little suckers. They drink through their leaves more than their roots early on, so don’t dry them out. But don’t turn your grow room into a damn rainforest either. You’re not Tarzan. Get a hygrometer. Watch it like a hawk.

Once you flip to flower, slash that humidity fast. 40 to 50% is the zone. Lower if you can manage it without stressing the plant. Buds are dense—especially with Northern Lights—and dense buds + high humidity = botrytis. That’s bud rot. It smells like death and looks worse. You’ll cry. I’ve cried.

Late flower? Go even lower. 30 to 40%. Dry air helps tighten up the buds and push resin production. It’s like the plant knows it’s dying and throws everything into making seeds it’ll never get to make. Tragic. Beautiful. Sticky as hell.

Ventilation is your secret weapon. Fans aren’t optional. You need air moving constantly—above, below, through the canopy. Stale air breeds problems. And don’t just blow air around—get it out. Exhaust fans, carbon filters, intake vents. Create a flow. Think of it like lungs. Your grow room should breathe.

Dehumidifiers? Yeah, probably. Especially if you’re in a swampy area or running a sealed room. AC units help too—cool the air, pull out moisture. Two birds, one compressor. Just don’t let them blast directly on your plants. That’ll dry them out and piss them off.

And hey—don’t obsess over perfection. You’ll drive yourself nuts. Plants are tougher than we give them credit for. Northern Lights especially. She’s like that chill friend who doesn’t complain even when you forget her birthday. But still—don’t make her suffer. She’ll forgive you, but she won’t forget.

Anyway. Keep it warm, keep it dry (when it counts), and keep it moving. That’s the gist. Everything else? You’ll figure it out. Or you won’t. That’s part of the fun.