What
size drainage holes should container pots have?
Something some
people don't remember to do is to punch out the drainage holes
in their containers for gardening. Because many people use
pots for other purposes than just gardening, many containers
now come with the marks for where the drainage holes should
be, but it is up to you to pop them out before you add the
soil.
If you need to
make your own drainage holes, use a drill bill 1/2" in
size - or use a smaller drill bit, redrilling the same hole
until it is 1/2" in size. Using 1/2" drainage holes
will give you adequate drainage of water for your plants.
You will need to have multiple holes depending on the size
of the container. You need about five holes per square foot.
After you drill
the holes, you can add a layer of newspaper to the bottom
of the pot before adding soil if you are concerned about soil
loss through the drainage holes.