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AND POTTING AQUATIC PLANTS
you begin, gather your tools and supplies: Containers, dirt, fertilizer,
knife, digging tool, scissors, a hose (with a handy shut-off) and
of course - towels. If you do not have a potting table or an area
designated for the job, use a tarp for a working surface. Choose a
cool, shady area for dividing and potting aquatic plants. Use damp
newspaper or sheets to cover bare plants to prevent the roots and/or
leaves from drying out.
squat pots wider than they are tall - they accommodate the horizontal
root structure of most aquatic plants, and prevent plants (especially
those taller emergents) from tipping over. Sturdy black plastic
tubs are ideal. Consider plant size and shelf depth. If you are
using pots with drain holes in the bottom, use newpaper or coffee
filters to keep soil in the pot until it compacts. Plants used for
filtration in phyto- and bio-filters are the exception. For these
plants, use mesh pots filled with pea gravel, not soil. This encourages
roots to take up nutrients from the water as it passes through.
aquatic plants perform the best when grown in heavy soils. Use a
chemical free heavy (clay) soil that does not have added organics.
Make a mix of 2/3 dirt and 1/3 sand - the sand allows good root
penetration and makes it easier for repotting in the future. Do
NOT use bagged potting soil - it doesn't compact well, and peat,
perlite, manure and other materials float and foul the water. Leave
at least 1" at the top of the pot for pea gravel or sand. The
main function of the soil is to hold plants in place and provide
trace elements as well as some nutrients. By repotting, the new
soil will increase the amount of nutrients available to the plant.
It also allows for easier fertilization until the plant becomes
potted plants require fertilizer occasionally. For best bloom, fertilize
lotus and waterlilies monthly during the growing season, twice as
often during the hot months (July/Aug.). Begin fertilizing when
you see new plant growth. Use a slow-release aquatic fertilizer
which comes in tablet form. Place the fertilizer well away from
the crown 1/2 to 2/3 of the way into the pot to prevent burning
the root. When potting new plants, put the fertilizer near the bottom
of the pot before adding more soil and the new plant. Stop fertilizing
in the fall when water temps drop into the 60's (except for water
hawthornes and trop lilies you want to push for more bloom).
Gravel and/or Sand: These
toppings help keep the soil in the pot and prevent fish from mucking
up the works as they root in the pots. Be sure to avoid crushed
limestone or "road rock" in your pond.
& Marking Pen: It
is a good idea to use a new label whenever you pot a plant - include
the name of the plant and, for future reference, the date. Use a
waterproof marker and insert the tag deeply into the pot, where
it will stay and remain hidden.
TIMING IS EVERYTHING !
Early in the spring, before signs of growth, is the best time to divide
lotus. Start dividing waterlilies and most other plants in spring
as soon as there are signs of new growth. Some, like Pickerel and
Thalia, like to get some good growth before being divided - wait until
late May/early June to divide these, and consider division every year.
Wait to divide Iris until late summer/early fall, so they can store
their energy to bloom early the next spring. If you divide them in
early spring, they will most likely not bloom that same year.
plants are so resilient, most can be divided throughout the growing
season. Be sure to stop dividing in late August/early September to
allow the plants to 'root in' before the cool weather sets in.
As a general
rule of thumb with marginal plants and submerged aquatics, up-pot
until you are satisfied with the pot size, then consider dividing
PLACEMENT IN THE POND
Depths for Aquatic Plants: Place newly potted plants
at shallow depths. Once established, move them deeper as indicated
below. Plants can be set on blocks to live at their desired depths.
The chart below is for during the growing season.
The planting depths below are for during the growing season,
and are intended as a guideline. Specific depths are listed for each
plant in the Plant List (available at Water's
Edge). See the list also for winter plant care. As a general
rule of thumb, never submerge more than 1/4 of the height of an emergent
Plants & Smaller Lotus
- 2" - 6" (varies)
Planting Depths reflect the distance between the top of the soil and
the water surface.
waterlilies anytime during the growing season- April thru August.
grow rapidly and some can even fill their pot within a season!! Repot
your waterlilies when they have jumped their pot or when you can no
longer find space in the pot for fertilizer tabs. A
good size pot for waterlilies is 16" x 7".
your tools and supplies.
- Fill the new container 1/2 to 3/4 full with your aquatic mix.
- Place fertilizer tabs near the bottom of the pot.
- Use a Hori-Hori knife or trowel to dig the lily out of its old
- The growing crowns are the tips where new leaves and buds emerge.
Find two types of roots - thick anchor roots and hairy feeder roots.
- Clean off most of the soil and cut away the old growth, leaving
enough rhisome (2-4") and roots to anchor itself in its new
- Place the cut end of the rhisome at the side of the pot below
the soil, with the crown pointing upward towards the center of the
pot at a 45 degree angle.
- Put 3-5 crowns in a 16 x 7 pan, for lots of blooms all summer.
- Add aquatic mix to cover roots and most of the rhizome, and top
with sand or pea gravel.
sure the crown is well above soil and pea gravel.
- Gently lower the
lily into the pond.
regularly throughout the growing season for good bloom.
AND SUBMERGED PLANTS
have a wide variety of growth habits - some grow from rhizomes, others
from a central crown, and still others with running stems. In most
cases, create a compacted mound of soil about 2/3 the height of the
pot. Place the plant on top of the mound, spreading its roots across
it. Cover the roots and fill in the pot, gently compacting the soil.
- Divide rhizomes
like Iris and Pickerel, and place the cut end against the pot, with
the growing end toward the center of the pot.
- Plants with
central crowns or stem clusters, single stems, and single crowns
can be divided & placed alone or in groups in the middle of
- Wrap cuttings
of runners on plants like Clovers & Pennywort around the mound.
Take 4" stem cuttings
from plants like Parrot Feather & Veronica. Place the cuttings
half-buried in a full pot. Submerged plants like Anacharis & Cabomba
can also be divided in this way.
regularly throughout the growing season for good bloom. DO NOT fertilize
submerged aquatics. They
take in nutrients through their leaves.
in the early spring, before there is any sign of new growth. Lotus
are extremely vigorous growers. The larger sizes need to be repotted
every 2-3 years, and the bowl lotus once a year... Their root structure
is a running tuber which, when confined, travels in circles around
the inside of its pot.
Use BIG BROAD ROUND TUBS with NO HOLES for your
a pot 20-24" x 10-12" or larger for full size lotus.
- Use a pot 14-16" x 7-10" or larger for semi-dwarf.
- Use a pot
8-12" x 5-7" or larger for the bowl lotus.
sizes are important, due to the running growing habit of the lotus,
and please - NO
square pots - the growing end can get stuck in the corners!!!
your tools and supplies.
- Put 1"
of sand on the bottom of the new container and fill 1/2 to 3/4 full
with your aquatic mix.
- Take the lotus
out of the pond and carefully dump the dirt/root mass out of the
pot, upside down onto a tarp. Growing ends of the lotus protect
themselves from winter damage by diving to the bottom of the pot.
The best tubers will be found wrapped around the bottom.
- Gently wash
the soil off of the tubers and unwind them, discarding the dark
and/or mushy ones as you go.
life of the lotus is in the growing ends - take care not to damage
or bruise them!
As you expose them, you will see sausage-like tubers, linked together.
The "links" are called internodes. . . the nodes are the
constrictions between them. New growing ends, leaves and flowers
emerge from the nodes.
- Cut through
the internodes to make sections that include one or more growing
ends (a sausage-and-a-half each). Float these in a tray of water
until you are finished dividing.
- Dampen the
soil in the container, making it muddy but not soupy. Select one
or two of your best divisions and make a shallow horizontal trench
for each. Gently lay them in with growing ends pointing up. Cover
the thickest part of the tuber with 1-2" of soil. Top all with
1" of sand.
Gently saturate the container and lower the lotus into the pond.
NOT fertilize lotus until it has standing leaves (late May). Thereafter,
fertilize your lotus regularly throughout the growing season. For
best bloom, fertilize twice as often during the hotter months - July
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