Perennials are the returning summer guests that pop up with gifts each year. Plant them once and you’ll see them grow larger and more prolific every summer season. That’s the upside.
The downside is that they tend to only come in two flavors at the nursery– a puny plant in a four-inch pot that will struggle through the summer, or a fully grown-out gallon size plant. Both are more expensive than annuals or vegetables, and they take up a lot of the budget.
But now is the perfect time to grow them yourself–you’ve already got out your seed-starting equipment from the early summer; you have plenty of heat and sunlight outside to grow them; and you have space, since you’re likely not growing anything else. We have six to ten solid weeks left to get those seedlings started, up-potted and in the garden before fall.
Perennials worth growing
While a gallon-sized perennial will run you anywhere from $15 to $40 at a nursery, a packet of seeds is a couple of dollars. With that packet of seeds, and a bag of seed-starting mix ($15), you’ll be able to grow a full tray of 50 baby plants (called starts). While there are endless perennials to consider, the easiest to grow, most colorful and likely to benefit pollinators are echinacea, yarrow, veronica, agastache, and salvia.
Echinacea—or coneflower, as it’s also known—has been bred to come in a wild variety of colors and shades, from shocking pink to blazing orange. Coneflower is a reliable plant that comes back, gaining size each year. If you cut the flowers they’ll bloom again, and it’s an absolute favorite of bees.
A tall (36”) rapidly spreading flower that can look like statice, yarrow gained popularity because it’s a garden workhorse. In addition to being beloved by pollinators like bees and birds, the taproots break up soil. The roots also collect nutrients, so it can remediate things like lead in the soil. Yarrow will bully out other plants and self seed, so you should plant it with the awareness you’ll need to do some manual control over it spreading too much.
If you have trouble growing your tall spiky flowers like delphinium and hollyhock, two flowers notoriously hard to grow from seed, then veronica is a great alternative. It comes in a dazzling array of colors, and is still a spiky flower, under twenty four inches. Veronica makes an amazing border plant because of its structure.
Agastache, also known as hummingbird mint, draws in hummers over and over to its dainty flowers on tall spikes. The real charm is that agastache isn’t uniform in color, but tends to go ombre. While you can get shades in every color of the rainbow, each plant will flash an amazing spectrum of colors in that color range.
There’s an annual and perennial version of salvia, and you’d be smart to get perennial versions in your garden. Known for its intense colors, salvia can be found in shades of grape, blue and, famously, red. The red will draw hummingbirds for miles. Salvia tends to only have a few spikes on each plant, up to 36 inches tall.
How to grow perennials
Into each of the cells of your seed trays, plant a few seeds, pressed lightly into the surface of damp soil. Cover the tray with a plastic dome and then put it outside in the sun. Water it daily with your hose on mist. You won’t want to pour water on these seeds, just keep them moist. The domes should have condensation on them at all times.
In two weeks you should see some germination. While it’s routine for not all seeds to germinate, most should. Once you have germination of 75% of the tray, take the dome off, but make sure the tray is always watered. You can add a bottom tray or a rimmed cookie sheet under your seed trays and fill them with water, so your plants always have access to it.
Once your seedlings are two inches tall, it’s time to transplant them to four-inch pots. Add an inch of potting soil to the bottom of the pot; carefully place your seedling, then add potting soil around it. Put the seedling in shade for 24 hours to recover from the shock of transplanting and then slowly move it back out into the sunlight. Keep the seedling watered daily through the heat of summer.
When the seedling is five to six inches tall it can be transplanted into the garden into a hole about twice the size of the four-inch pot, with some fertilizer. It should still have enough time to get rooted before fall hits.