Simple watering guide

End overwatering! Simple watering directions for any pot

Overwatering kills more houseplants than any other problem. If the airlessness of soggy soil doesn't kill the plant outright it weakens it so other problems take hold, everything from mysterious weakness (jade tree as an example) to inability to fight off things like scale (a Ficus specialty).

To water a potted plant perfectly, indoors or out:

  • Water only when the top inch of soil is dry or the root ball loses weight.
  • Pour measured water slowly onto the soil until some seeps out the drain holes. Stop. Wait 20 minutes. If the seepage has been reabsorbed, the amount you added is how much you should apply every time the plant begins to dry.
  • Expect a plant to use water more quickly when the light is brighter. Expect the same plant to use water more slowly if it has fewer leaves or less light.

 Have questions "Why?" about these directions? Read on!

Earning your A+ in Pot Watering

Our friend Jane Suhail, with decades of experience as an indoor landscape technician, explains watering potted plants so well:

How often you water is determined by the number of leaves and amount of light. How much water you use is determined by the size of the pot.

So change a watering schedule seasonally

Since winter days are much shorter than in summer, water less often in winter. Make the change as soon as you shift a summered-out plant back to its dimmer, warmer winter home or when a dense leafy plant thins out in winter's low light.

A rubber plant that needs water every few day when it's on the back porch in July may need water only every two weeks in near-dormancy by a window in winter. Regardless of season or foliage density, give each plant enough water to wet its whole root ball at every watering, but water less frequently in lower light months and sites or when the plant has fewer leaves.

About fertilizer in the water? Wait! Fertilize only what is already actively growing.

Digging in to those watering guidelines

Good, airy potting mix is 50% solid, 50% pore space. If half that pore space is filled with water clinging to the crumbs of solid matter, and the other half is just full of air, it's perfect. Water fills 25% of the space around those happy roots. So a one gallon pot may hold a quart of water.

Below: Once it's filled with potting mix the four-cup orange pot will take 1 cup of water to be fully moist. The smaller pressed paper pot requires just a half-shot.


Water only when the root ball is dry or at least the top inch of soil is dry. How can you tell this? Lift the pot -- a dry plant is lightweight -- or press your finger into the potting mix.

Once you know it's dry, fill a big measuring cup and use it to water the plant, following the guidelines to pour it slowly onto the soil surface and stop when water begins to seep out the bottom drainage holes into the overflow basin.

Why is the next step to check back in 20 minutes? If water remains in the overflow basin, that plant needs that much less than you poured in. If the plant's roots or pot has absorbed the overflow within 20 minutes, the plant needs just about what you poured in.

Once you know how much water a given plant needs give the plant that amount each time you water.

If you repot -- up or down in size -- you must revisit the plant's water needs. Repot only when the plant uses its water so quickly that you can't keep up with its schedule, or it's tipsy because its top has become so big it overbalances the root ball and pot.