Perennials from seed
The last thing you may be thinking of now that we are into the month of August is sowing more seed, but there is still a bit of time left to sow fast growing crops of lettuce, spinach and radishes, and you can even get a jump-start on new perennial plants for next year’s garden by sowing seed now.
It’s true, certain varieties of perennials are difficult to start from seed. Some take weeks or months to germinate and others need exposure to cold temperatures before they will sprout. Some perennials take several seasons to flower nicely and some need vegetative propagation – by division or cutting.
Fortunately, there is a long list of perennials that are easy to start from seed by sowing directly in the garden. Black-Eyed Susan (Rudbeckia) and Brown-Eyed Susan have golden petals in mid-to-late summer and can be direct sown through midsummer. If you grow these plants, you already know how readily they self-sow.
Purple Coneflowers (Echinacea) are very similar to Rudbeckia in that they spread easily on their own by self-sowing. Purple Coneflowers are sturdy plants which are heat and drought tolerant and have few insect or disease problems. It’s also easy to harvest your own Purple Coneflower and Rudbeckia seed for planting (or simply scattering) around your garden.
Blanket Flower (Gaillardia aristata) produces mounds of showy yellow and red blooms throughout the summer, and Sweet William (Dianthus) is a readily self-sowing annual producing clusters of small carnation-like flowers in white, pink and red on 15-inch tall plants.
‘Russell Mix’ Lupine (Lupinus) have tall flower spikes which bloom in June in colors of pink, purple, blue and white. Again, this perennial readily self-sows – I have seedlings coming up in my border bed now – and it is easy to harvest your own seed for sowing around your landscape.
Shasta Daisies (Leucanthemum x superbum) love a sunny spot and produce cheery white blooms with yellow centers in early summer. They also do well in tough growing conditions.
Additional perennials for direct sowing include chives and garlic chives, Blue False Indigo, Purple Poppy Mallow, Siberian Forget-Me-Not, Verbena and violet.
If you decide to sow perennial seed now, you can do so by starting seed in a small “nursery” bed in the garden, in pots or flats (as for indoor sowing), or simply plant directly where you want them in the garden.
According to the National Gardening Association, keep pots of seedlings in a partially shaded spot outdoors, or place in an empty cold frame with the top removed and covered with a section of snow fence. Containers should be overwintered in a cold frame.
Young perennials in a nursery bed can be mulched for extra winter protection and transplanted next spring to their permanent location. If you plant the seeds in their permanent location, you can provide extra protection over the winter with mulch as with your nursery bed perennials.
Sowing perennial seed in midsummer means you will have an inexpensive source of good-sized perennial plants next spring ready to start blooming.