One of the most common problems that first-time growers face is that they notice their marijuana leaves curling up at the edges. If the serrated leaf edge starts to curl or fold upwards, then this is a sign that the growing conditions are not ideal.
Common causes of leaf curling include:
- Excessive humidity
- Excessive heat
- Root problems
- Over-watering
The good news is that these problems are all relatively easy to fix. For example, if the marijuana plant that is having the issues is the one closest to the grow light, then this is a sure sign that it’s a temperature related problem. If the plant also shows signs of burning or spots, then moving the light further away could fix the issue.
If the plant isn’t showing such signs, don’t rule out a temperature issue yet. Try ventilating the room or installing fans to keep the air circulating so that you don’t have to worry about the plants getting too hot. Use a hygrometer to keep track of the humidity also.
If you’re sure that it’s not a temperature issue, the next things to look at are the roots, and how often the plant is being watered. Yes, you need to water marijuana regularly, but not so that the soil is soaking. Over-watering is a common mistake.
Your pots should have drainage holes to allow excess water to flow out. If the roots are left in stagnant water for a long time, then this will create a situation where they are starved of oxygen and are unable to take up nutrients.
Root problems make the plant droopy and can stunt its growth or make the leaves twisted. It is possible for it to recover if it is transplanted into a pot with fertile soil and watered appropriately, but it can take some time.
The leaves that are ‘cupped’ may not ever recover, but over time new leaves will grow in their place, and they should be healthy if you take good care of them.
Cannabis is quite resilient, and it will recover from most things, given time and care. If you’re worried about the health of the seedlings you are growing, the best thing to do is to seek advice early. If root problems are caught fast, then you have the best chance of ensuring that the seedling thrives and achieves its full potential early on.