How to Water a Seedling in a Big Pot

Published Mar 04, 2019

by Nebula Haze

Sometimes you want to start your cannabis seeds or clones directly in their final container, without transplanting from smaller containers to big ones. This is completely possible, but you need to make sure you’re watering plants properly. It’s also important to note that plants may grow a little slower at first when you start them in a too-big container, though good watering practices should help! Read on to learn exactly what to do.

How to water seedlings or clones in a too-big container

When starting seedlings in a big container (bigger than 2-gallon), it’s important to slowly give just a little bit of water at a time until your seedling “grows into” its pot. This prevents overwatering, which slows down seedling growth.

Seedling in a large 5-gallon pot

By watering the right amount in the seedling stage, you can speed up growth significantly, especially during that first week or two.

For new seedlings you should give water in a small circle around the plant instead of saturating the whole container.

Don’t give water again until the top inch of potting mix is dry to the touch (which should be less than a few days if you did your job right). This makes sure your seedlings get a perfect mix of air and water so it grows as fast as possible.

Make sure to give water slowly in a small circle around seedlings until you get runoff water out the bottom of the container. This makes sure that water is getting to your plant’s roots but isn’t over-saturating the container.

After plant has started to “grow into” it’s container, the top inch of potting mix will start drying out quickly (less than a few days). At this point, you can start normal cannabis watering practices which means you saturate the whole growing medium until you get about 20% runoff water

Cannabis seedlings that were planted in a too-big container

Summary: How to water cannabis seedlings or clones in a too-big container

Beginning Stage

This is for when you’ve just planted your cannabis seeds or clones in a too-big container. By giving your young plants less water at a time following the steps below, you prevent overwatering which can slow down seedling or clone growth in a too-big container.

  • Pour water slowly in a small circle around the base of the seedling (I first pour my water into a solo cup so that it’s easy to pour water around each plant).
  • The circle should be ~2 inches in every direction from the base of your seedling (or if your seedlings are bigger, about the width of the leaves).
  • Every time, make sure to continue watering slowly in a circle until you get runoff water out the bottom of the container. Make sure to remove runoff water so it doesn’t get re-absorbed through the bottom of the container.
  • Don’t water again until the top inch (up to your first knuckle) is starting to feel dry to the touch.

Regular Watering Stage

Once your marijuana plants have established healthy root systems that can support the size of your container, you can start watering as normal.

  • Once the top of the growing medium is drying out quickly, in less than than 2-3 days, you’re past the beginning stage.
  • Switch to normal watering practices. This means that you are watering the entire container until you get 20% runoff every time. Then don’t water again until the top inch (up to your first knuckle) is starting to feel dry to the touch.

Important: Always wait until the top inch (up to your first knuckle) is starting to feel dry to the touch before watering your plant again. This prevents both overwatering and fungus gnats 🙂

Transplanting for faster growth

Transplanting means that you start your plants in a relatively small container, and then transplant the plants as needed so that their roots never run out of room.

Transplanting will provide your plants with faster growth if done right. This is because transplanting allows you to set up an environment where your roots are getting access to plenty of water and air. However, transplanting can stress your plants (and slow down growth) if not done properly. When transplanting, it’s important to carefully move plants so that their roots are not disrupted in any way. This means moving plants before they get root-bound, and creating a hole in the potting mix of their new container so the plants can be placed right in without disturbing the roots.

If you plan on starting your plants in a small solo cup and transplanting your plants to bigger containers as needed, take a look at this transplanting guide.

These seedlings in solo cups will need to be transplanted to a bigger container once they grow about 3 sets of leaves

While transplanting makes it easier to give your young plants access to plenty of water and air, it can stress the plants if not done right, and it can also be too much work for some growers. So many growers start their plant in it’s final container.

When seedlings or clones are started in a large container, it can be difficult to get enough air to the roots until the plant is bigger and drinking a lot. Thisis because when the potting mix gets soaked, the seedling roots just won’t be able to drink it fast enough, and the roots will end up sitting in stagnant water with very little acces to oxygen. The growing medium has to dry out on it’s own, which can take a while, and your plant will be droopy and overwatered until the roots start getting access to air again.

Some growers start their seedlings or clones in a bigger pot, or even the final container they plan to use. While this can slow down growth of young seedlings, you can minimize this effect by watering young plants correctly when they’re started in a too-big container.

Full Cannabis Transplanting Guide

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