Here at the Park, our horticulture team is hard at work preparing the gardens for the winter!
The English Garden is made up of annuals (plants that complete their life cycle in one growing season) and perennials (plants that live longer than two growing seasons). Some of these perennials are adapted to our climate, but others are not.
Dahlias and canna lilies are perennials that cannot survive our cold winter, so we remove them from the gardens and overwinter them in storage to replant next year. This is something you can do at home too!
Here are the steps we take to overwinter our dahlias.
First, we wait until at least one good frost before digging up the dahlias. The frost helps redirect the plant's energy into the tubers. Tubers are root adaptions that store nutrients, allowing the plant to overwinter and grow the following season.
After the plant is dug up, the stem can be cut off a few inches above the roots and tubers. The remaining dirt is removed, and the tubers are stored upside-down for a few days. This helps the extra moisture run out of the tubers.
The prepared tubers are stored in peat moss or wood shavings in a cool, dry place over the winter (about 8-12 degrees Celsius). Next spring these plants will return to the gardens as soon as we are past hard frost.
Overwintering outdoor tropical species is a wonderful way to garden more sustainably as you do not need to purchase the plant again. You can use the above method to keep canna lily rhizomes over winter as well.
This time of year, our team is also planting bulbs that will transform into beautiful flowers come spring. We till, rake, and plunge holes to prepare the soil for the tulip and allium bulbs. These flowers are adapted to our climate and need a period of cold to enter dormancy so they may flower when the warmer temperatures come.
As our team continues to put the gardens to bed for winter, we dream of the bright colours reappearing next spring.