HOME PLANTS GUIDES QUESTIONS ABOUT US SHOP SEARCH

Is It Better To Water Plants From The Bottom Or The Top?

"Is it better to bottom water or top water plants?"

Generally speaking, it makes no real difference whether you top water or bottom water your plants.

All houseplants really want from you is sufficient water around their roots. As well as a small reserve of water to be "held" in the surrounding growing medium, that they can access in the coming days or weeks.

Bottom watering a Pitcher Plant sitting in a container of water

Is this the best way to water a potted plant?

Whether you provide water from the top or the bottom doesn't usually matter in the grand scheme of things. But there are advantages, disadvantages and myths around this practice. We're going to go through all these shortly.

What's the difference between top vs. bottom watering?

"Top watering" means you provide water to the top of the plant's soil surface. Then with the help of gravity, the water will seep down through the growing medium right to the bottom of the pot.

"Bottom watering" is when you pour water into a vessel, like a container or a drip tray, and then sit the plant and its pot into it for a short time.

The water is pulled upwards into the dry growing medium by capillary action. If there is enough water in the vessel, all of the growing media will eventually be saturated.

If done correctly the result of each type of watering is exactly the same. Your plant is well watered and there is sufficient moisture around the roots to keep it going until you need to do it all over again.

Top watering the surface of the soil
Bottom watering a tray of water

Use the slider above to tap / swipe back and forth to see the difference between Bottom Watering vs Top Watering.

Subscribe


Top and Bottom Watering Myths

Sometimes there is a genuine benefit or requirement to top or bottom water your plants, and we look at these later. However, in most cases, it's down to personal preference.

Often someone telling you that you must do it a certain way is perpetrating one of the common myths. Here are three of the most popular reasons given along with more detail and context.

1

"Bottom watering means plants only absorb the water they need".

This one is entirely false and really makes no sense at all when you think about it.

And here's why.

The reality of this claim
In this example, "plants only absorb the water they need" really means "the potting mixture will absorb as much water as it can hold".

The plant hasn't absorbed the water. The potting mix has.

Plants will never immediately "drink" or use all the water you add to the potting mix.

Much like a battery is designed to absorb and store energy for later use, the primary purpose of watering is to "recharge" the dry growing medium with moisture.

The roots will then access this moisture as and when they need it, ideally for a few days, a week or even longer.

When you water a plant, of course you're wetting the soil and roots simultaneously, and a tiny amount of this will start to be absorbed by the plant immediately.

How the water gets into the growing medium, either from the top of the pot or its bottom, doesn't make any difference. The roots will only ever absorb the amount of water they need in that given moment. Bottom watering will never change that.

2

"Bottom watering prevents overwatering".

Most plant parents are encouraged to use pots with drainage holes in the bottom. This is one of the very best ways to prevent overwatering and root rot, as excess water will simply drain out of the holes and can then be poured away.

If you're bottom watering the idea is that after the growing medium has been fully wetted, you lift the pot, let any excess water drip out, and then put it back into its outer container.

Yes, this likely would help prevent overwatering. But equally, if you chose to top water, you would just wait half an hour and then lift the pot from the outer container. If there is water at the bottom, you will then pour this away.

So this one has definitely has elements of truth to it. But it's not a compelling reason to bottom water houseplants exclusively.

Further reading -
Are you overwatering your plants? - The Signs to look out for

3

"Bottom watering encourages strong roots".

This originates from gardeners' advice that you should water new outdoor plants heavily and deeply, rather than "little and often".

The view is that by doing this, you will encourage roots to grow deeper into the soil to reach the moisture deep down and this helps prevent excessive shallow roots and provides resilience in times of drought.

Outdoors, I understand this reasoning as the roots have lots of choices for where they can grow and you can help control this. Indoors it's different because plants are confined into relatively small pots. So regardless if you choose to top or bottom water the roots will still grow strongly and eventually fill the entire pot due to gravitropism.

When is it better to Top Water?

Sometimes there is a genuine need or benefit to top water your houseplants.

  • You have pests such as Springtails living in the soil.
    For convenience, bottom watering will typically involve multiple plants being watered at the same time. For example, you might gather many plants and dunk them all together.

    However, if one of your plants has pests, their eggs or larvae could escape and contaminate the water before hitching a ride onto the next plant to be dunked. This method could also spread fungal diseases between plants.

    As an example, I had Springtails in my new Moth Orchid. I was bottom watering these plants due to the free draining nature of Orchid bark, but as they shared the same water, before long, my entire collection was affected.
  • To help prevent salt and mineral buildup.
    Most tap water around the world and some fertilizers will contain certain minerals and chemicals. Top watering can help flush excess salts and mineral deposits to the bottom of the pot and eventually out of the drainage holes.

    Constantly bottom watering will keep these salts and minerals in the potting mix, so top watering can help keep the root system of your plants healthier.

When is it better to Bottom Water?

Bottom watering can have some advantages over top watering. Here are 4 examples when it can work well.

Philodendron malay gold that's been bottom watered to prevent fungus gnats

The top of the soil is dry, but an inch or so down and you'll find moist soil.

  • Fungus Gnats.
    Damp soil is a requirement for Fungus Gnats to thrive. They live and lay eggs in the top inch of soil, so the most organic and effective way to get rid of them is to take that moisture away for several weeks.

    Most houseplants won't survive that long without any water, so bottom watering will allow some water to be pulled up into the growing medium, where the lower roots will then have access to water.

    TIP - Just don't leave the pot in the water for too long otherwise, eventually, all the growing medium, including the Fungus Gnats living area, will be full of moisture again, and you won't break the cycle.
  • The potting mix is dehydrated.
    Once your potting medium dries out completely, it becomes hydrophobic. The potting mix will shrink and create channels for water to flow through; additionally, it will resist and repel water. This means water will quickly run through these open channels and out the bottom.

    If you bottom water it will force the potting mix to gradually absorb water and should return to a more functional state. (Sometimes bottom watering isn't enough because the dry soil is too far gone so you'll have to try the Immersion Method instead).
  • You have a houseplant with sensitive leaves.
    Certain plants like African Violets sometimes don't respond well to wet foliage as it can disfigure or mark the leaves with brown spots. Others like, Echeveria can easily get water trapped in them which can encourage disease or rotting.
  • Your houseplant needs to be permanently wet.
    Some houseplants such as Umbrella Grass, Venus Flytraps or Sarracenia, must never dry out. If you can set them on a drip tray or an outer container that will permanently hold water, you will prevent this from happening and see when the water level is going down.

How do you "bottom water plants"?

All you need is for your plant to be growing in a container or pot with drainage holes. Then grab a vessel, it could be a saucer or a large dish. Even a wok would work!

Fill this vessel with room temperature water and then lower the plant into the water. Leave it for at least five minutes to give it time for the soil to suck up water, but ideally not longer than an hour or so.

How long each plant needs in this "water bath" will vary, but it's ready to be taken out as soon as the upper surface becomes damp.

Remove the plant and give it something like 30 seconds for any excess water to drain / drip out. And that's it, job done.

Trays, large pots or bowls all make good watering basins

Simple drip trays or larger containers can all be filled with a few inches of water to help you water your houseplants.

My opinion and recommendation

If you've read this entire article, you should hopefully already know that top watering vs bottom watering will typically come down to personal preference. Just do what's easier for you or takes less time!

There are occasional instances where one of these watering methods will be better than the other and doing this will likely help you keep your plants healthy or resolve a problem.

I almost always water using the top method. The primary benefit is time saving and less effort. I have a lot of houseplants, including a good number of thirsty tropical plants and some heavy larger plants.

Top watering vs bottom watering will normally come down to personal preference.

Setting up a bottom watering station every few days and bringing all of them to the station would take forever. So by me going to each plant with a watering can it's much quicker and more efficient.

That said there are two very important benefits of bottom watering which I'll vouch for though. The first is bottom watering to help deal with Fungus Gnats, of which I've had moderate success over the years.

I also like doing it with plants in very porous potting mixes like Moth Orchids, especially when I'm trying to apply feed (add it to the container of water before dunking your plants in it). This gives the bark mix time to soak it up evenly and restores moisture levels, meaning I need to water them less often.



About the Author

Tom Knight

Tom Knight

Over the last 20 years, Tom has successfully owned hundreds of houseplants and is always happy to share knowledge and lend his horticulture skills to those in need. He is the main content writer for the .

Also on Ourhouseplants.com


Comments


Six Reasons You Can Trust Us

Our Houseplant Guide Hub - containing lots of how to guides

For even more Houseplant help you may like our

Houseplant Guides

Top