Overwatering vs Underwatering Marijuana: How can I tell if my droopy cannabis plant is over or under-watered?

by Nebula Haze

A common question for new cannabis growers is how to tell if your drooping cannabis seedling is over or under-watered. It's common for new growers to overwater their weed, but that doesn't mean that underwatering doesn't happen too. Never fear, once you get a feel for it, it's easy to tell how often you should be feeding your plant and what is the true cause of your drooping.

If your marijuana shows signs of drooping in normal temperatures, it almost always means you're over or under-watering your plants, either by watering too often, or by giving too much water at a time when the plant is too young to drink it all.

How often should I be watering my cannabis plants?

Water your marijuana when the top of the growing medium starts feeling dry up to your first knuckle. You should stick your finger 1-2″ into the soil. Wait if it's damp, but water your plant once it feels dry.

Soil dries in 1 day or less? Give More Water at a Time (if that doesn't work, you may need to transplant to a bigger pot)

Soil takes more than 3 days to dry? Give Less Water at a Time

Learn everything you need to know about watering your plants!

An over watered cannabis plant will have leaves that are full of water, so the leaves will be firm to the touch and generally curling down (even from the stem of the leaf) almost as if it has too much water weight to hold the leaf out straight.

An under watered cannabis plant will have leaves that are brittle, limp, and lifeless. They will need to be watered every day just to keep them wet. The leaves will seem to be drooping but won't appear as rounded and full as an over watered cannabis plant.

Leaves feel papery and thin on an underwatered plant, growing medium is dry

If it gets worse….

Now that you've (hopefully) got an idea about whether it's over watering or underwatering, what's the cure?

Complete Over-Watering Tutorial

Complete Under-Watering Tutorial

Or continue reading….

Over-Watering vs Under-Watering Remedies

Overwatering

Symptoms: seedling is droopy, growing medium is moist, damping off

Most common causes:

When a cannabis plant is "overwatered" it has less to do with the water and more to do with oxygen. Plants can even grow directly in water (hydroponics) but in order to thrive, roots need oxygen. In hydroponics, that's accomplished by dissolving oxygen into the water. But when plants are grown in a container, too much water = not enough oxygen.

When a plant's roots are sitting in water, they quickly use up all the oxygen until the growing medium starts to dry out. Without enough oxygen at the roots, the plant will start showing symptoms of oxygen deprivation. Luckily, there are many steps you can take to prevent overwatering your cannabis plants.

While overwatering can display many different symptoms, most overwatered cannabis plants look droopy, like this…

Despite what seems like an obvious cause, several different scenraios can end in overwatering. Here are some of the most common trouble-makers:

Big Pot, Small Seedling

When you have a small plant in a very big pot, it's easy to overwater because the roots aren't drinking much yet, and the big container takes a long time to dry out.

Notice how the plants in smaller containers have grown more than the plant that was put in a big container as a seedling. It's common for plants in too-big containers to grow a little slowly at first.

How to fix:

(Recommended) Start seedlings in smaller container until they're growing vigorously, then transfer to a larger container

If seedling is already in a big container, there's still hope! When watering, give just a little water at a time in a small circle around the seedling. Then allow the top inch of your medium to mostly dry before watering again. Once the plant is growing vigorously, start watering as normal (with extra runoff water coming out the bottom every time)

These small cannabis plants (below) were put in big pots, and were given enough water to support a much larger plant. The plants couldn't drink all the water that was given to them and as a result, their roots weren't able to get the oxygen they needed and started "drowning." Once the roots are out of commission, the leaves start drooping.

One way to prevent this from happening is to