Dahlias

(Question)

Hi there, I am just wondering being new to Flowers if I could grow my own Dahlias? We’re hoping for a light pink and white. What we would need? Type of soil if specific? How long they would take to grow? We are in a temperature zone of about 22-27 celcius through our summer (Near owen sound ontario) and they can be sun facing at all times. If you could email me more info that would be fantastic!

(Answer)

You can certainly grow dahlias in your area. Dahlias grow from a tuber which will not survive in the ground over winter in most pasts of Canada including Owen Sound. You can plant new tubers every year or lift the tubers in the fall and store indoors. You will find a good selection of dahlia tubers in your local garden centre right now.

Dahlias can be planted outdoors in mid-May. They like a full sun (6-8 hours/day), well drained location.   If your soil is on the heavy side, lighten it by adding some compost or composted manure.

Check the label for information on how deep to plant (generally 4-6 in/10-15 cm) and how much distance to allow between plants. (generally 18-24 in/45-60 cm). The spacing is important to maintain good air circulation around the plants. Crowding can contribute to the development of downy mildew in humid weather.

Taller varieties may need staking. Some gardeners use tomato cages to support their dahlias.

Do not water newly planted dahlias as this can contribute to rot. Wait till you see shoots appearing and then water regularly – at least twice a week when there is no rain.

No fertilization is required at the time of planting but your dahlias will benefit from an application of liquid, organic fertilizer 30 days after planting and then monthly during the blooming season. Be sure to avoid a high nitrogen fertilizer which will give you lots of leaves at the expense of fewer blooms.

Blooms should start to appear 8 weeks after planting. You could also get a head start by planting your dahlias indoors right now and moving them outdoors mid-May assuming you can provide a sunny indoor location or sufficient artificial light.

If you want to store your favourite dahlia tubers over the winter, wait till after the first heavy frost then remove the tops to within 6 inches of the crown (where the stem joins the root) and carefully lift the tubers with a garden fork. Gently brush the soil off the tubers and lay them out to dry in the sun for a few hours.  Before storing, remove any tubers that are infested, dead or withered. Bury in dry sand, soil or compost and store indoors in a cool spot

Enjoy growing some dahlias!