Gardening > Canna Lilies
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This page was developed to share my gardening and landscaping experience
with others.  The site contains only general information on different plants.  I
do not guarantee all information to be accurate.  I do not accept any
responsibility for anyone's growing success.  Please consult with your plant or
seed supplier for detailed planting instructions.
General Information:

Canna Lilies have attractive, tropical looking, leaves.  They flower from about
mid-summer until fall.   There are several varieties on the market.  The color
of the flower are usually shades of red, yellow, and orange.  The leaves are
usually green, purple, or variegated.  Canna Lilies prefer full sun, but do
alright in partial shade.  Cannas are winter hardy in zones 7 to 10.  They may
be planted as far north as zone 3, but the roots must be lifted and stored
indoors for the winter.  They are planted after the last frost in the spring.  
They must be lifted before, or right after, the first frost of the fall.  

In addition to the regular cannas, there are dwarf varieties.  The dwarf
varieties will only get 30 to 36 inches tall.  Most of the regular varieties will
grow around 3 to 5 feet tall.  Some varieties are supposed to get 8 to 10 feet
tall under the right growing conditions.  

Growth and Propagation of Canna Lilies:

Cannas grow from a thick, multi eyed, rhizome type of root system.  Canna
Lilies are usually obtained from root division.  They also produce seed.  Seeds
take longer to start and you may not always get a plant identical to the
parent.  Cannas grow and spread fairly fast.  They are often considered to be
weeds in tropical regions.  One benefit with having to lift the plants in the
north is that it helps to keep the plants under control.  I started out with cigar
size roots.  The first year they grew to a basketball size mass of roots with
eyes shooting in all directions.   Some people will start Cannas indoors a
couple weeks before the last frost to get a jump on the season.  People with
established beds will often only lift a fraction of their plants.  If they lifted
them all, they would have more than they could use or give away.  A friend or
neighbor who grows Canna Lilies will probably be more than happy to give
you some.  

About mid summer Canna Lilies will shoot a flowering stalk and start to
bloom.  The plants will spread and shoot additional flowering stalks which
will continue to bloom until fall.  The plants will then form seed if the flowers
are not dead headed.  The seeds form inside a pod and will be about the size of
a pea.  They are black in color.  Dead heading the flowers will encourage the
plants to produce more flowers.  Dead heading will also keep the patch true to
the variety you planted and under control.

The roots of Canna Lilies have to be lifted for winter storage in regions that
have frost.  A frost will turn the leaves black.  The roots will freeze and rot if
left in the ground.  The roots should be lifted right before, or right after, the
first frost.  The entire root clump may be lifted intact or in larger sections.  
The stems should be cut off a couple inches from the rhizome.  Some of the
loose dirt may be removed to make the clump more manageable.  Some of the
fine roots that grow off of the rhizome can also be trimmed.  The roots should
be placed in a cardboard box or paper bag.   Some people will pack them in
peat moss or something similar.  The box should not be sealed.  It helps to cut
some holes in the box to allow air circulation.  Air circulation will keep the
roots from developing mold and rotting.  The roots must also be allowed to
retain enough moisture that they do not shrivel up.  They should be stored
around 40 to 50 degrees fahrenheit.  An attic, unfinished basement, or crawl
space are possibilities.  You must prevent the roots from freezing, but it
should not be too warm or the roots will dry out.  The roots must also be kept
dark to help keep them dormant.  Don't be afraid to check on them a couple of
times throughout the winter.  

If you wish to start Cannas from seed, it is best to start them indoors to get a
jump on the growing season.  Some people will take a fine sandpaper and
gently remove a little bit of the
black coating on the seed.  This will allow
water to penetrate the seed much quicker.  Be careful not to sand too deeply.  
The seeds should sprout in about 2 weeks.  They may be transplanted
outdoors after the last chance of frost.  

The roots will need to be divided every 1 to 3 years.  It will depend on the size
of the root you start with and growing conditions.  Each root division must
have at least one bud.  It is best to leave 3 to 5 buds per root division.  This
will give you a more compact plant which provides a better flower display.  
The roots should be divided in the spring.  A lot of people will clean and
divide the roots when lifting in the fall.  I find that leaving the clump intact
over winter gives the plants a quicker start in the spring.  Older sections of
root will not have new buds and may be cut out and discarded.  Roots that
were lifted for the winter should be divided a couple of days before planting.  
This will allow the wound to heal over before planting.  

Caring for Canna Lilies:

Cannas require basic weeding, and inspecting for bugs or disease.  I have to
treat ours for Japanese beetles.  They like lots of water in well drained, rich,
organic, soil.  Cannas that do not get enough water will be smaller in size.  A
good flower fertilizer will also make a difference.