Growing tomatoes from seeds is hard work: they need the correct temperature, moisture levels, and lighting to grow successfully. When they do something unexpected, it’s easy to wonder if something is wrong. What does it mean when tomato seedling leaves point up at night? Is it normal?
Tomato leaves pointing up at night is a normal occurrence, especially in young seedlings. Young, immature plant leaves often point upwards towards the sky, but grow out of this habit as they age. Occasionally, leaves pointing up can indicate an issue with the amount of light the plant is receiving—either too much or too little.
Keep reading to learn more about why your tomato seedling leaves are pointing up at night and how to know if you need to change something.
Why Do Tomato Seedlings Point Up At Night?
Tomato seedlings, much like many other immature plants, will have upright leaves as they begin to grow. This is totally normal and usually means the plant is happy and healthy.
Some plants will even close their leaves at night and face them towards the sky. Though the reason isn’t entirely clear, it’s thought that these plants have a circadian rhythm (just like animals do) that dictates when they rest and when they grow. As daylight comes back around, the leaves open up and flatten out and take in the sun’s rays.
Problems That Can Cause Tomato Seedling Leaves To Point Upwards
While it’s often perfectly normal for your tomato seedling leaves to point upwards, especially at night, there are a feweasily-corrected problems that could be causing it to happen. It’s important to monitor your tomato seedlings’ light and water levels to make sure they are experiencing ideal growing conditions.
One of the most common problems causing upward-pointing leaves is receiving too much sunlight. If your plants are under artificial grow lights constantly, they may receive more sunlight than they can handle.
When this happens, they will close their leaves and point them upwards to reduce the amount of surface area receiving light. This allows them a “break” from the sunlight for a bit so that they can recover.
If you have grow lights on your plants at night and they are pointing upwards, try turning off the grow light for a few more hours each day to see if the leaves go back to normal.
Interestingly, not receiving enough sunlight can also cause your tomato seedling leaves to point upwards. When plants don’t receive enough light, they become tall and leggy, trying to grow closer to their light source so that they can receive more light. If your tomato seedlings are tall, thin, and have upward-pointing leaves, try moving your grow light closer to the plants to see if the problem goes away.
If your tomato seedlings seem happy and healthy, their leaves pointing up at night isn’t cause for concern. However, if they’re especially leggy or have burned leaves from receiving too much sunlight, try altering their lighting setup to see if the problem resolves itself. By carefully monitoring your plants’ growing conditions and making adjustments when necessary, your tomato seedlings will thrive.