Why are my cannabis seedlings so tall?
Question: Why are my young marijuana seedlings getting tall and dying? They’re growing all stretchy with long stems, and aren’t making new sets of leaves.
These cannabis seedlings are growing tall and thin (and falling down) because they need more light.
Answer: When marijuana seedlings are growing tall and thin like that, it means they need more light.
“Leggy” seedlings need more light
When young marijuana seedlings are starving for light, they often show signs of lots of other problems, but if they’re getting really tall without making any leaves, it’s a sure sign it needs a brighter environment.
To increase the amount of light, you either need to get stronger grow lights (what grow lights work for growing cannabis?), or move your current grow light closer to your plants.
Some growers bury the extra stem to make seedlings short again, which works, but as long as you start giving your seedling light it will do a “push up” and rise back up, strengthening its stem in the process! Here’s what to do right away…
Get 1-2 CFL bulbs and keep 2-3 inches away from the tops of your seedlings (be careful not to let seedlings grow into the light!)
Get 2 x 40W ‘daylight’ CFLs (can support 1-4 seedlings)
You can get more light later when the plant is making buds, but getting 2 CFLs should stop the stretching so you have a few more weeks.
After adding light, you’ll see the new growth is much bushier and closer together, but the original stems will not get new leaves. Some growers will bury plants like these up to the point where there’s leaves, but there’s nothing wrong with just growing plants out as long as you have the height!
Learn about other common cannabis seedling problems!
Your marijuana seedlings are growing so tall because they need more light. When young marijuana seedlings are starving for light, they often show signs of lots of other problems…