This week’s episode of Grow it, Minnesota, is all about growing flowers from seed. I interviewed Amy Kainz of Milkweed.and.Daisies, who has a half-acre garden filled with pollinator-friendly plants, including many easy annuals she has grown from seed. She also grows some that are a bit more complicated, such as snapdragons, but we’re talking easy today.
For garden beginners, an annual flower is one that grows, blooms and dies in a single season. Unlike perennial flowers, which come back each year, annuals will bloom for most of the summer, adding color to the garden. You can buy annuals in 6-packs or flats from nurseries and garden centers each year, which is a great way to get instant color. You can also grow them from seed, which is a great option for the budget-conscious gardener or those who just like a lot of plants.
Here are seven of my favorite easy annuals to grow from seed.
I love the open faces and wavy look that cosmos add to the garden. Best of all, these are super easy, because you just scatter the seed on the ground after the danger of frost has passed. (That’s mid-May in most of Minnesota.) You can cover the seed with about a half inch of soil, though I often just rough up the area with my foot and call it good. The seed germinates in about a week and you’ll start to see the ferny foliage coming up. Within six or so weeks, you’ll have flowers. This year, I’m growing Sensation Mixture from Seed Savers Exchange, which gets more than 4 feet tall. This is a vintage cosmos and was named an All-America Selection in 1936. I grow cosmos around the edge of my insectary garden, giving it a cottage garden feel. Cosmos don’t need a lot of fertilizer; they do best in poor soil, so put them in your toughest spot.
Talk about easy — marigolds can be seeded outdoors or inside under lights. Amy told me she often starts them using the winter-sowing method as well. Last year, I grew Safari Orange marigolds from seed and they were a highlight of my vegetable garden area. Their bright orange blooms brightened up the garden from June until a late frost. I started them under lights in mid-April and they grew fast! I had to hold them in pots for the weather to warm up, but once they got in the garden they flourished. I saved some seeds from the plants and plant to grow them again as edgers in my ornamental beds.
You can’t talk about easy annuals without mentioning zinnias. They come in dozens (hundreds?) of types and varieties. The tall ones are the best ones to choose, if you want to attract pollinators. You can plant them outdoors after all danger of frost has passed or start a few indoors to get a head start on blooming. This year, I plan to set out a few winter sowing containers with zinnias to see how they do. Zinnias like full, full, full sun and average garden soil. Keep cutting your zinnias for bouquets to encourage flowering.
Calendula is easy to grow and blooms prolifically, as long as you don’t love it too much. Over-watering and over-fertilizing are no-nos with this flowering herb. Calendula is sometimes called pot marigold and its blooms look a bit like both zinnias and marigolds. The yellowish orange blooms will continue all summer as long as you deadhead the plant. Some gardeners plant calendula because it will attract aphids away from more valuable plants. Calendula does not need full sun and I’ve grown it in moderately shady spaces with good success. Calendula will reseed.
Speaking of reseeders, sweet alyssum forms an annual groundcover that reseeds readily. This is an easy plant to start from seed. Just scatter the seed on the ground in early May and lightly firm it into the ground. Seeds need light to germinate and light a damp soil to stat, so maybe pick a week with some gentle rain in the forecast. The seedlings emerge in 10 days and once flowers start, they will bloom all summer.
If you have children around the house, please plant sunflowers—especially the big ones! The huge plants and big flower heads are sure to spark an interest in gardening. Also, the seeds are large, so it’s fun for kids to plant their own plants or even use sunflowers to build a fort. Sunflowers naturally like a sunny spot and they do best in soil that is well-drained and has compost added. Plant the seeds about a half-inch deep in the ground after all danger of frost has passed. The really tall ones may need some support. On some varieties you can harvest the seeds for snacks. It’s also great fun to watch the birds harvest the seeds off the huge heads, sometimes performing bird acrobatics to get at them.
If you want to bring in bees and hummingbirds, salvia is the plant to plant. In the past, I’ve grown Yvonne’s Giant salvia, though mine never hit the giant status they did attract hummingbirds. Many of the blue salvias, such as Black and Blue, are large and beautiful plants that pollinators love. The colors range from purple to light blue. Salvia’s like full sun and well-drained soil. I would start seeds indoors under lights for best results.
A quick warning on salvia, however: While researching this post, I checked many of my usual online sources and most were out of salvia seeds! Check your local nursery for seeds or plants, if this is an annual you want to grow.
Which are your favorite annuals to grow from seed?