Named after the herbalist and physician Jean Ruelle, the genus ruellia is made up of many species, including this wild petunia. Technically, ruellia violacea is not a petunia, but classified as a member of Acanthaceae, a plant family consisting of tropical shrubs, herbs and vines.
Provided with a combination of full sun and cool, damp soil, wild petunia will reward you with a profusion of stunning purple flowers. The swift-growing plant can quickly grow to a metre in height. There are many uses for ruellia in the landscape: they can be mixed into an annual bed, planted around the perimeter of a patio or porch, accenting short and tall plantings, or used as a defining border. The full foliage and pleasant, purple flowers add a splash of colour to the garden and fit in seamlessly anywhere they’re planted.
- Latin Name: Ruellia humilis
- Life Cycle: Perrenial, usually grown as an annual in Canada
- Canada Hardiness Zone: 6-9
- Days to Maturity: 75-100
- Planting Depth: 3-4 mm
- Plant Spacing: 30 cm
- Growth Habit: 60-90 cm tall
GROWING INSTRUCTIONS
Among one of the most popular cultivated flowers, petunias bloom abundantly in containers and as borders. They grow and develop quickly and have the ability to reach maturity by late spring. It’s common, easy and cheap to buy petunias from the nursery, but much more rewarding to start from seed. It’s worth your while to experience how easy it is to grow an abundance of your own petunia flowers.
Start seeds indoors at least 10-12 weeks before the last frost date. Seeds will need light to germinate. Sow them on top of a moist starter mix and gently press them into the surface. Cover your flats or pots with plastic wrap and put them in a warm place with indirect sunlight. Seeds should germinate in about a week. Remove the plastic as seedlings emerge. When they have a couple sets of true leaves they can be transplanted into their own pots. After the danger of frost has passed, move them outdoors to gradually harden them off.
When selecting the spot to plant your petunias, consider that they do best in full sun with afternoon shade during the summer. The perfect temperature range for petunias is 16-24 degrees. They’ll tolerate temperatures as low as 4 degrees.
Make sure petunias get about 3-5 cm of water per week. They don’t like to stay dry, but can develop root rot or get leggy if the soil is too damp. Pay attention to flowers in containers, as they will dry out faster.
Plant petunias in loose, fertile and well-draining soil. Compost or fertilizer can be added at the time of planting. During the summer through the fall, feed every couple of weeks with a liquid fertilizer.
Petunias can be pinched back when they’re young. This will fill out the plant with more branches, leading to more blossoms. Deadhead consistently to get the most out of your petunias. Light frosts and freezing temperatures will eventually kill off the flowers.
When you grow your own petunias from seed, you’ll have the pleasure of enjoying their beautiful blooms from spring straight through the fall.
QUICK FACTS
- The name ‘’petunia’’ comes from the word ‘’petun,’’ which means tobacco in Brazil. These two types of plants are related and petunia can be crossbreed with tobacco.
- Petunia seeds will remain viable for 3 years if stored in a cool, dark place, ideally between 4 and 10⁰C. After that, the germination rate may start to go down.
