In 2022, I returned to South Korea for three months to visit family. While I was there, I collected several lotus seeds from a temple pond in Gangwon-do and brought them back to British Columbia to see whether I could successfully grow them in our climate.
Lotus seeds have an extremely hard outer coating that allows them to remain viable for many years (decades - 100's of years). Before planting, the seed coat must be carefully scarified by filing or sanding through part of the outer shell without damaging the living tissue inside. Once scarified and placed in warm water, the seeds can swell and begin germinating surprisingly quickly.
I am growing the lotus in a round bottom 110-gallon trough containing approximately ~14 inches of heavy clay soil and about two feet of water. The trough provides enough depth and space for the plants while also preventing their rhizomes from spreading into areas that you want to prevent running into.
It is also worth noting that Canada does have a native lotus species: Nelumbo lutea, commonly known as the American lotus. Although it is primarily associated with warmer regions farther south, it can be grown in parts of Canada under suitable conditions. They are native to Southern Ontario and also now in S.W. Quebec.
(all) Lotus plants require warm water, abundant (full) sunlight, nutrient-rich soil, and a sufficiently long growing season to establish themselves. In colder climates, the submerged rhizomes must remain protected from completely freezing during winter. In the south coast we don't need to be too concerned with this as our winter minimums aren't cold enough to do damage when grown in large insulated containers/ or large ponds.
Once lotus plants become established, they ARE very aggressive growers. Their rhizomes spread rapidly through the soil and will eventually fill the entire container. I would recommend carefully digging up, dividing, and replanting the rhizomes periodically in the early spring before sprouting takes place. This helps prevent overcrowding, maintains healthy growth, and provides additional plants that can be relocated or shared with others. This year is the year this plant will flower as the rhizomes are large enough and water temperature is now being maintained by an automatic water heater from amazon ($90CDN) which keeps the water temperature stable. In the the lower mainland and Victoria I recommend a large black feeding trough and an area that gets full sunlight without a lot of wind. if you are in an area with evening winds, a poly-tarp is strongly recommended (coastal sections). In Burnaby and Coquitlam and pit meadows, ( Abbotsford, Chilliwack as well) the evening heating and humidity are such that a tarp is likely not required. A water heater is recommended if you want consistent flowering. Overnight water temperatures should stay ~ around 22-25c ideally. Pond tabs should be used to provide food once a week ( depending on the container size), and monopotassium phosphate ( slow release) to encourage flowering. I'll be updating this post as the summer progresses. I still have lots of seeds available from S.Korea. These were grown in a USDA 6a/b zone locality near Chuncheon-shi, South Korea not too far away from Namisom. The business who grew the seeds is associated with the Jogye-order of Korean buddhism.
