GROWING BUTTERFLY BUSHES FROM SEED
Q. I have saved seeds from my 'Black Knight' butterfly bush. What is
the best way and when is the best time to start them?
It is easy to grow butterfly bush (Buddleia davidii) from
seed. Be aware that seed saved from a named cultivar such as 'Black
Knight' will not produce identical offspring because they are the
result of sports or crosses of davidii with other species of
Buddleia. The only way to ensure identical offspring is to take
cuttings from the parent plant. However, growing butterfly bushes
from seed can result in interesting offspring. It's fun to see what
When to Start
Plan to start
your seeds 10 to 12 weeks before the last expected frost, which
occurs mid- to late May in Allegheny County. Use a soilless seed
starting planting medium that contains a mixture of vermiculite,
perlite, bark and/or sand, rather than potting soil or soil out of
Best Soil Mix
are light and drain well, yet hold moisture evenly. They are less
likely to harbor disease-causing organisms than soil.
Moisten the mix
before filling the containers. Recycled cell packs saved from
purchased plants are a good place to start butterfly bush seedlings.
Make sure they have been thoroughly cleaned and disinfected by
rinsing them in a solution of 1 part chlorine bleach to 10 parts
will have to be transplanted into larger containers as they grow.
Butterfly bush seeds are very small -- about the size of a dust
particle. You can mix them with sand to help distribute them more
Press the seeds
gently into the surface of the seed starting mix, but do not cover
them because they require light to germinate. Place them in a bright
area where the temperature stays around 68 degrees. Do not allow the
soilless mixture to dry out once germination has begun. Water with a
spray bottle set to a fine mist, or place the cell packs in a
shallow container of water and allow them to absorb water from the
bottom to avoid disturbing the seeds. They should germinate in about
After they Germinate
seedlings are growing, keep them evenly moist but be careful not to
overwater. If the mix feels moist, do not water. It is best to keep
them in bright light (or under fluorescent lights), and to grow them
in slightly cooler temperatures, around 60 degrees.
'Potters Purple' Butterfly Bush
seedlings have grown to fill the cell pack, and roots are growing
through the drainage holes in the bottom, transplant them into
larger pots. The size of the pot should fit the size of the seedling
-- perhaps 6 to 8 inches.
After they are
established in larger pots, begin pinching the seedlings back to
encourage branching. Otherwise, they will grow like straight sticks.
Pinch back to buds midway down the main stem; they will develop into
branches. Once we are past danger of frost, you can plant them out
in the garden.
garden seeds indoors