Soil mix for coleus
You can use plain perlite or a soilless seed starting mix for your
Never use soil out of your garden. No matter how good your soil is,
it may contain disease-causing organisms that will damage or kill
Cuttings started in pure perlite will have to be transplanted into a
regular potting mix once they root well.
Those started in a soilless mix can continue to grow in it as long
as you fertilize regularly.
Some seed starting mixes contain a slow-release fertilizer, which
reduces the need for additional fertilization.
Taking coleus cuttings
Use a sharp knife to take cuttings. It will make a clean cut that
will heal rapidly.
When taking cuttings from coleus and other tender perennials, take
4- to 6-inch cuttings that have several sets of nodes -- the point
on the stem where the leaves attach. Nodes contain undifferentiated
tissue that can develop into roots or leaves, depending on their
environment. Make your cut just below the lowest node you wish to
If possible, choose a stem that is not in bud or blooming. If not,
remove any flowers and/or flower buds to divert that energy into
At least two nodes should be inserted into the rooting medium to
ensure good root development. One or two pairs of leaves above the
rooting medium supply the leaf surface that will provide the
nutrient reserves required to produce the new root system.
Remove any leaves that will be beneath the rooting medium and any
that will droop into it.
Moisten the rooting medium and fill the containers. Water the
containers thoroughly to settle the rooting medium and remove any
air pockets. Add more if necessary so that the rooting medium is
about a half-inch below the rim of the container.
Use a pencil or a dibble to create a hole in the center of each pot.
If you simply jab the cutting into the rooting medium you may damage
the cutting and it will not develop properly, if at all.
Although many plants root more readily if you use a rooting hormone
such as Rootone, it is not necessary with coleus. They root quite
readily without it. Insert the cuttings into the rooting medium and
water each pot again to settle it around the cutting.
Place the cuttings in an area with good air circulation and bright
but indirect sunlight.
Once cuttings show signs of new growth, they have rooted.
Then you can start using a water-soluble fertilizer according to
label directions. You can also mix the fertilizer at one-quarter
strength, and fertilize every time you water.
Moving coleus outdoors
Next spring, when we are past danger of severe frost, plants will
have to be hardened off before placing them out in the garden. The
process takes about 10 days. Start putting the rooted cuttings
outside in a sheltered, shaded location for a several hours. Allow
them to stay out longer and to receive more sun every day until they
are out in full sun all day.
When the danger of frost passes completely (coleus is extremely
frost-sensitive), plant them out in the garden.
It is usually safe to set tender plants out from Memorial Day on.