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.