These
easy-to-grow, low-maintenance plants provide color to landscapes
from May until the arrival of frost. After the first hard frost,
they are typically destined for the compost pile, but that doesn’t
have to be their fate. While they are often treated as annuals, they
can be successfully overwintered indoors to be enjoyed again next
year.
Preparing geraniums for overwintering
Geraniums must be dug or moved indoors before the first frost, so
don’t wait until the last minute. Before bringing your geraniums
indoors, inspect them for pests and diseases. Diseased plants, or
those infested with insects, will be difficult to overwinter, and
you run the risk of the disease or pests spreading to other plants.
Discard any plants with spots/discoloration on leaves and stems,
wilting/shriveled or rotting, or infested with insects.
Once you’ve selected the plants you wish to keep,
you’ll need to decide to overwinter them. This can be done by
growing them as houseplants, storing them as bare-root plants, or
taking cuttings.
Overwintering geraniums as potted/house plants
Geraniums can be overwintered indoors as houseplants. This is
particularly easy if they are already being grown in pots, but
plants that are in the ground can also be overwintered this way.
Carefully dig plants, place them in an appropriately sized pot with
drainage holes, prune them back by one-third to one-half, and
thoroughly water them.
Treat potted geraniums like other houseplants and place them in a
bright, sunny window or provide supplemental lighting. They will do
best when daytime temperatures are around 65°F, with nighttime
temperatures slightly cooler. They will become lanky when grown in
warm conditions and not given enough light. Pots should be watered
when the growing media becomes dry. Plants can be pinched back
occasionally to produce well-branched, stocky plants.
Storing geraniums as dormant bare root plants
When storing geraniums as bare root plants, dig them from the ground
or remove them from their pots and remove the soil/potting media
from their roots. Put plants in a large paper bag and place it in a
cool (45-50°F), dry location. Alternatively, some people will hang
their plants upside down. [to top of second
column] |
While plants are being stored, most leaves will fall
off the plants, and branch tips may die back. Come March, remove the
plants from storage. Plants should be cut back to firm, green tissue
and then planted in pots and cared for like other houseplants until
they can be placed outdoors (May).
Taking geranium cuttings
Geraniums can also be overwintered as cuttings. Use a sharp knife or
pruning shears to take 3-to 4-inch cuttings from the ends of
branches (terminal shoots). Remove the lower leaves and dip the cut
end into rooting hormone. Then, stick the cuttings into a pot (with
drainage holes) with rooting media like perlite, vermiculite, or a
sand-peat moss mixture and water.
Make sure the growing media remains moist so the cuttings don’t dry
out. A plastic bag (clear) can be placed over the pot to help retain
moisture, but make sure to monitor for mold growth. Plants should
then be placed under bright lights.
It can take anywhere from 4-8 weeks for plants to root. Once the
cuttings have rooted, they can be placed into 3- to 4-inch pots and
grown indoors until being brought outdoors.
Geranium cuttings should be put deep enough into
rooting media so they can stand on their own. A plastic bag
can be placed over cuttings to help retain moisture.
Good Growing Fact of the Week:
Annual geraniums aren’t “true” geraniums; they are members of
the genus Pelargonium, while true geraniums, like wild geranium,
are in the genus Geranium.
[SOURCE: Ken Johnson, Horticulture
Educator, University of Illinois Extension]
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