Old-fashioned annual flowers like nasturtiums and zinnias have made a huge comeback in gardens and containers. I think it’s because of an increased interest in supporting pollinators and butterflies, the popularity of cut flowers, and because they’re beautiful and easy to grow.
All of the annual flowers below are quick-growers and can be direct seeded outdoors in May in garden beds and containers. Or, if you have the space and inclination, you can get a jump start on the growing season by sowing the seeds indoors in mid to late March. You can also pick up transplants from your favourite garden centre this spring.
Most annual flowers need a site with at least six hours of full sun and compost-enriched soil. If direct seeding, keep the soil moist until the seedlings emerge and are growing well.
Easy to grow annual flowers:
Nasturtiums
Nasturtiums are an annual obsession of mine and I plant at least a half-dozen varieties every spring. I direct sow the large, wrinkly seeds in mid to late May, planting them about one centimetre deep.
Read the seed packets carefully and select nasturtium varieties that will fit in your garden space. Some grow just a foot tall, others cascade several feet, while some produce long vines that need a sturdy trellis or fence for support. My preferred varieties include orchid flame, bloody mary, phoenix, and baby rose, a new variety that is super petite.
Calendula
Calendula (also called pot marigold) is a favourite in my garden for its heavy bloom of yellow and orange flowers. I haven’t actually planted calendula in years as it’s a prolific self-sower and new seedlings pop up each spring.
I pull any that are growing too thickly or in the wrong spot and leave the rest to please the bees and butterflies. Calendula is valued for its medicinal properties and a common ingredient in salves, soaps, and lotions. It’s also a long-lived cut flower lasting about two weeks in a vase.
Cosmos
Cosmos is a vigorous annual flower that can grow up to 150 cm tall, depending on the variety. It sports daisy-shaped blooms in vibrant shades of pink, magenta, lavender and white. They’re very bee and butterfly-friendly and the flowers make excellent cut flowers.
Sensation giant is the classic tall-growing cosmos, but if you’re short on space, try cosmio, a new variety that grows just 50 cm tall and has magenta and cream streaked flowers.
Poppies
My grandmother always planted annual poppies in her back garden. The papery flowers only lasted a few weeks but when they were in bloom, nothing else compared. I still grow annual poppies, but as they are self-seeders, it’s been years since I had to sow fresh seed. They wander around my raised beds blooming heavily from late June through late July, attracting more bees than any other flower.
Standout varieties include Danish flag, lauren’s grape, and mother of pearl.
Zinnias
Zinnias have come a long way in recent years. While gardeners still love to grow traditional varieties like state fair and giant dahlia, thanks to the rise of local cut flower farms there are some very unique new introductions.
Of these new zinnias, my favourites include queen lime red’ and queen lime orange which have beautiful ombra flowers with lime green centers. Plant enough zinnias so that you have plenty for bouquets, but leave some flowers for the monarch butterflies and bees which also adore the pretty blooms.
Other easy-to-grow annual flowers that can be direct seeded include marigolds, sunflowers, love-in-a-mist, and bachelor’s buttons.
