Watering your indoor plants should be something that gives you relaxation and reduces stress. Think of the simplicity of the process. Start by filling your watering can. Then you play some of your favorite music and glide from plant to plant, pouring the liquid of life into the dry soil of your plants, and you can feel them appreciate the love. You can encourage growth and replenish your houseplant's essential requirements with little effort. That being said, as a first-time plant owner, it is not necessarily instinctual to know how much water to give each plant. To make matters more confusing, how are you supposed to know how often to water your plant.
Let's start with the type of plant you have, as each category has different watering needs.
Cactus and Succulents
This category of xeriscape plants needs the least amount of water, but they still need it! Knowing the type of cactus you have will significantly help you keep them standing up in their pots. Like African Milk Tree and Pencil Cactus, Cacti with leaves need more frequent watering than a Barrel Cactus. Cacti with spines tend to require water less frequently.
The soil mixture of succulents and cacti consists of bark, perlite, some soil, and other coarse amendments, so when you water these types of plants, you will have to water them thoroughly. It's a misnomer that you should add just a little bit of water because they don't like a lot of water. It's counter-intuitive. Soak each plant thoroughly until the water has completely saturated the soil medium. If your succulent is in a small container, 4" in diameter or less, you will have to water it more frequently. If you want to water less, try massing like succulents in a larger container, so more moisture is captured in the soil.
If your succulents are in terra-cotta or concrete pots (great choice as they wick the water away from the roots and prevent root rot), you will have to water more often. If your succulents are planted in a pot with no drainage, you will have to pour out the excess water after each watering. They will be happy you made an effort.
There is no schedule for watering cacti or succulents because many variable environmental factors are at play. You might keep the temperature in your home very high or very cool, and this can affect how much water your plants need. The best method to determine when to water your drought-tolerant plants is to check the soil throughout the week. When you notice the soil has been dry for about a week, give it a good soaking. These desert plants need a period of drought to feel at home.
Houseplants that have trunks, bulbous bottoms, or think vines will be able to hold more water than plants with thin stems and therefore will not need to be watered as often as ferns, calathea, peace lilies, and other tropical foliage plants. The larger the plant's root ball, the less frequently you will be watering. This, of course, is all dependent on the temperature, time of year, and air humidity. The best way to know if your plant needs water is to understand your plant's watering needs. Do not rely on guessing. Some hardy houseplants like Ficus elastica, peperomia, dracaena, monstera, and philodendron have slightly thicker leaf membranes and are good choices if you cannot water your plants often. When you notice the soil is almost completely dry, it is time to water. If you are unsure if the soil is completely dry, wait a day or so to prevent root rot.
Palms and Dracaena
Palms appreciate frequent watering, contrary to what you might have imagined. Water them when the top inch of soil feels dry. You could be watering as often as twice a week in the growing season and as little as every few weeks in the winter. Palms and dracaenas are sensitive to salts in the water, and leach the soil every few months to eradicate any build-up. The foliage tips will start turning brown if the salts remain in the soil, so if you see this starting to happen, flush the soil with filtered water. Remember to check the soil before you water your plants! If the soil is moist, do not add any more water and wait until the soil is almost completely dry.
Tender Leaf Houseplants
Leafy plants like ferns, calatheas, syngoniums, and spathiphyllums with tender leaves, need more water as they transpire water more readily. They also cannot store a lot of water in their foliage like succulents, cacti, and plants with woody stems.
When you water indoor plants with tender leaves, never wait until the soil has completely dried out. Their roots need a constant source of moisture, and if they are deprived of water for too long, the leaves will start to turn brown. Feel the soil, and if the first top 1-3" feels dry to the touch, then thoroughly water the soil. Make sure you water the soil evenly and let all of the excess water drain out of the bottom of the pot before placing it back into the cover pot or saucer.
Watered smaller plants in smaller pots need more frequently.
Terra-cotta and concrete pots absorb water, so they are better for succulent types of plants and plants that you tend to overwater.
Pots with no drainage holes can be used, but they should have a layer of gravel on the bottom.
After watering, the pot should be tipped and drained to remove the excess water not absorbed by the soil and roots.
Fill your watering can after each to allow water to reach room temperature
Water your plants thoroughly when they are dry until the excess water runs through the drainage holes.
Use filtered water when possible, or consider using rainwater if you have chemicals in your water.
When watering succulents and cactus, water until all the soil is drenched.
Get to know your plants by picking them up (if possible) when dry, then when wet, so you will learn to know just by feeling if your plants need water.
If the soil becomes extremely dry, it will start to compact. Use a soil probe or a pencil to poke aeration holes into the soil's surface. This will help the water work its way into the soil to open up the capillaries and help with water absorption. Do not worry about damaging the roots, they will be fine as long as you don't poke every square inch of the soil!
Watering your plants should be relaxing, therapeutic, and more importantly, a "me time" moment. You will begin to know your plants more intimately over time, and soon, you will know by looking at your plants when they are thirsty!