These plants are prime candidates for bottom watering: Plants with hairy or fuzzy leaves, such as African violets, or plants that don't like getting their leaves wet, such as snake plants, Philodendron verrucosum, and P. micans.
Plants like epiphytes, succulents, Snake plants, Calathea, Aloe, more mature Maranta, Sedums, Kalanchoe, Begonias, African violets, and Pothos have shallow roots. If you prefer to bottom water these types, keep them in shallow containers so the wicking action can reach their roots or else supplement with top watering.
The main advantage of bottom watering is that it lessens the risk of overwatering. After all, the soil can only absorb so much. And with this method, you can't flood your pot with more water than the soil can absorb, which is easy to do with top watering (especially if your pot and/or soil don't drain well!).
Can you over water by bottom watering? Yes, if the plant is sitting in water too long, you can still overwater your plant through bottom watering. However, bottom watering is a more controlled method of watering your plants.
That's not the case when bottom watering. All you need to do is set the potted plant (be sure it has drainage holes) into the bathtub, sink, or another container that's filled with a couple inches of water. After 15 to 20 minutes, the plant will have absorbed the exact amount it needs—never too little or too much.
Watering is a critical part of plant care, and bottom watering can help prevent yucky things like fungus gnats.
The downside of bottom watering plants
In terms of plant health, there aren't a lot of drawbacks to watering plants from the bottom. However, one consideration would be that continual bottom watering could lead to a build up of minerals and excess salts in the growing medium, especially if you're using tap water.
If you're ready to give bottom-watering a try, it's really quite simple. Fill a bowl or saucer with room-temperature water, and mix in some fertilizer, if needed. From here, you can simply place the plant in the container and let it sit for 15 minutes or so.
If you don't have a drainage hole in your pot, you probably shouldn't use it for an outdoor plant, unless the plant will be sheltered from rain. You need to micromanage the amount of water going into your pot; if it get's drenched in a downpour, all could be lost. More soil means more moisture for longer.
For most of pothos, bottom watering ensures they are getting just enough water they need. It does take some time to bottom water, but in allows pothos to absorb just the right amount of water it needs, and it also prevents wasting water.
Because the water isn't going top-down, it doesn't remove any salts from the soil. Bottom watering is more time-consuming—you have to check your plant, fill the tray, wait for it to absorb, and drain the excess as well. We'll be honest: for larger plants, this method can take quite a bit of time.
He recommends: 'Using a mixture of bottom watering for every day with top watering to wash away the build-up of salts and minerals will keep your plants healthy, strong and well-watered. ' The build-up of salts should be dealt with every couple of months by watering from above.
How to Use Pots with No Drainage Holes. Some experts suggest using a layer of pebbles as a sort of drainage layer in those pots without drainage holes. This technique allows excess water to flow into the space with the pebbles, away from the soil and, therefore, the roots of your plant.
– Most houseplants prefer warm or tepid water over cold water, which can shock your plant. Warm water absorbs into soil best. – Some houseplants are sensitive to tap water. Let water sit overnight for chlorine to dissipate before using.
Possible Salt Buildup Problem. A common problem with bottom watering is the buildup of excess salt on the soil or sides of clay pots. This happens over time when tap water is used instead of distilled or filtered water.
There is a handful that can keep gnats at bay, including geraniums, lemon thyme, lavender, and Mexican marigold.
To avoid attracting any nasty gnats in the first place, it's best to bottom water your plants. Get a large flat tray, container, bathtub or sink with an inch of filtered or rain water. Place your plants into the water in only their nursery pots. Leave your plants for 15-20 minutes to soak up any water they might need.
How to Prevent Fungus Gnats. Neither fungus gnats nor their larvae can survive in dry soil, so let your soil dry out completely between watering as often as possible.
Bottom watering has advantages such as preventing mineral deposits on leaves and reducing the risk of fungal diseases. Additionally, it promotes healthy root growth by encouraging roots to reach deeper into the soil.
Watering aloe from the top is the most common method; just be sure not to wet the leaves. You can water from the top by pouring water into the pot. Or set your plant in a container of water, allowing the water to get soaked up from the bottom. Either method is fine, but the result is the same.
On the other hand, watering longer but less frequently, “deep watering,” produces deep roots that mean lawns can better survive periods of drought. The ideal watering schedule is once or twice per week, for about 25 to 30 minutes each time. Taking care of a lawn doesn't have to be an overwhelming, all-consuming task.