In general most house plants are watered from the top, however, watering plants from above may not be the best for a few reasons. The leaves on house plants like the African violet may become spotted or damaged. Of course it’s difficult to thoroughly water plants from above without some water splashing on the leaves.
For most people, watering from the top down works fine. When using this watering method it’s important to not overfill the pot with soil. Keep the soil level about one-half inch from the top of the pot. The best way to soak the entire root ball, soil and root system is to fill the pot with water and slowly allow the water to soak through the soil with the excess flowing out the bottom of the pot through the drainage holes.
Another watering method is to reverse the process and water from the bottom up. Simply take a saucer and place the plant on the saucer. Then add water and allow the soil to soak up the water until the soil media is damp to the touch or until you’re sure the soil is completely soaked.
Make sure you DO NOT let the plant sit in water after the soil has been complete soaked. When plants sit in water for long periods of time the roots can become damaged. Roots need oxygen, when submerged in water they can suffocate. Watering by method the soil should be completely wet after a half-hour or so. If the soil continues to soak up water add more water to the saucer.
When placing a plant in its growing container inside of a decorative container or planter make sure the decorative pot does not hold excess water and the growing pot sits in a puddle of water. It’s best to use a piece of foam to raise the growing pot off the bottom of the decorative container to create air space.
Another type of bottom watering system works well also, it’s a wick type system. You’ve seen those ads on TV for more absorbent paper towels that wick up or soak up water. A wick watering system works very much the same. Special planter watering systems are on the market but you can make it simply by using a cord inserted through the drain holes with the cord in contact with the water. As the soil dries out, water gradually soaks up through the wick and waters the soil.
When watering houseplants use room temperature water or a little warmer. You know how it feels when you get hit with cold water, plants feel the same way. Cold water can cause problems just like very hot water can, stay with room temperature for best results.