Tropical plants are small slices of the exotic, warmer climes from whence they came. Though we can hold on to their tantalizing sight and smell throughout the pond season, come late fall and winter, we need to help these warmth-loving plants make it through our harsh Canadian winter.
Most tropical plants can be kept as potted plants in the wintertime. Once our evenings reach a consistent 10 degrees Celsius, it’s time for your tropical plant to move indoors. Prepare a pot with planting soil, and dig around the root ball of your tropical plant, place your plants in fairly dry soil in a sunny window. We would recommend watering only once a week.
Come spring, your tropical plants will need to be acclimated in the spring by putting them outside once the temperature is above 10 degrees Celsius consistently day and night. Start by leaving them outside, during the day only, for a week, then begin leaving them out over night every other day. But, ensure all threat of frost is gone before putting out tropical plants.
The popular Cannas provide colour to your water garden all summer, but when the season begins to come to an end, you will want to overwinter this gorgeous blooming tropical plant properly so that you can enjoy them next pond season. In the fall, Cannas should have all their foliage cut back, leaving only a 2 inch stem above the ground. Carefully dig up the rhizomes after the leaves have yellowed, died back or been killed by frost, but before the ground freezes. Timing is key here – the longer you can wait after the first freeze before cutting, the more food the plant stores for the winter.
Once you have your clump of rhizomes, shake off the excess soil, and rinse to remove extra dirt. Dry the rhizomes in a well ventilated area, around 20 – 25 degrees Celcius. Cannas need one week to dry. Once the rhizomes are dry, remove any excess foliage, and store in a cool, dark and humid place with good ventilation. Fruit cellars and cool basements work well. Do not store the rhizomes in an attic or garage where they may freeze. Check throughout the winter and discard shrivelled, diseased, or insect infested rhizomes.
Lotus need their foliage to be completely brown before it is trimmed. The foliage and spent flower heads should be cut back and the containers dropped in the deepest part of the pond where the water will not freeze. If, however, lotus must be trimmed while stems are still green, cut stems above the water level, or the plant will in effect drown. Water will get into the tuber through the hollow stems. If the pond is too shallow to prevent ice from forming all the way to the bottom, remove the plants, pots and all, to a place where they can be kept cool, moist and dark. If they are allowed to dry out, they are finished.
The Pond Clinic only sells hardy water lilies. We don’t stock tropical lilies because they can be too delicate for our planting zone. But we thought you’d still want to know how to take care of your hardy lilies! The only time our hardy lilies need to be brought inside over the winter is if your pond does not meet the planting requirement, typically a 2 foot depth. In most cases, the foliage is cut back and the whole plant is left in its lily pocket over the winter, to be divided and repotted as needed in the spring.
If you pond is shallow and will likely freeze solid, remove the old leaves and stems from the lily and bring planted pots indoors to cold storage, approximately 5°C, for the winter. Keep planted lilies moist and in a dark area at all times. More lilies are lost from drying out than from freezing. Return plants to the pond after the ice has melted the following spring.
There is no guarantee that any plant, water garden or terrestrial, will survive to grow another season, but it may be worth the investment you have in your plants to give it a try!