Growing Zinnias with Cassie
by Cassie Bond
I love a yard full of colorful flowers in the summer. Each year, despite my not-so-green thumb and limited time to devote to the process, I make a little more progress on my flower beds. I’ve always preferred perennials because you buy and plant them once, then hopefully enjoy them for several seasons. But over the last few years, I found myself drawn to a few zinnia patches I saw around town, and last summer, I finally gave in and tried my hand at growing them.
The seeds I planted thrived in the corner of the yard I chose, and I enjoyed watching them bloom into the early fall last year. I joined a Facebook group of other zinnia growers to learn their tips and tricks, and saved a jar full of seeds to plant this year. Since they grew so well last season, I planned to expand my bed this year.
I had heard the term “volunteer” plant thrown around, but didn’t really understand what it meant until this spring. As I was preparing my bed to plant new zinnias, I was shocked to realize that I already had several growing! It turns out that by leaving my dead and spent blooms on their stems through the winter, they dropped seeds that sprouted on their own this season. In other words, the annual I had put off planting because annuals are “too much work” doesn’t always act like an annual after all.
I still had several bare patches at the start of the growing season, and no zinnias at all in the expanded area, but I used my saved seeds and was able to fill those spots in fairly well. My flowers aren’t as evenly distributed, and I don’t have as much color variety as I did last year when I started from scratch, but for the return on investment, I couldn’t be happier!
Zinnias tend to be especially prolific, but all of the following plants are likely to “self-seed” in USDA Zone 6B (where winter temps drop to between -5°F and 0°F).
Zinnias (especially open-pollinated varieties)
• Expect some color variation, especially from mixed seed packets.
Cosmos
• Germinate after the soil warms
• Bloom until frost
Larkspur
• Seeds fall in summer and sprout in fall or early spring
• Prefers cooler weather
Love-in-a-Mist (Nigella)
• Produces beautiful seed pods that scatter easily
Bachelor’s Buttons (Cornflower)
• Often returns thicker each year
California Poppy
• Does especially well in well-drained soil
Cleome (Spider Flower)
• Can become prolific if happy
Verbena Bonariensis
• Technically a tender perennial but readily self-seeds in Zone 6
If the idea of volunteer plants appeals to you, too, the following tips will help your bed fill in more evenly:
• Don’t deadhead the last flowers of the season. Leave plenty of seed heads until after a hard frost.
• Wait to clean up. Leave stems standing through winter.
• Delay mulching in spring. Thick mulch prevents seedlings from emerging.
• Weed carefully in late spring. Zinnia and cosmos seedlings often don’t appear until May in Zone 6b.
• Lightly scratch the soil in fall or very early spring to help seeds make contact with the soil.
• Avoid pre-emergent herbicides in areas where you want volunteers.
Apparently, one of the most important tips is to spend 15–20 minutes every week pulling or hoeing the cool-season weeds (chickweed, henbit, bittercress, etc.) in early spring before the zinnias start to sprout. Since zinnias don’t germinate until the soil warms, you won’t accidentally pull them at this stage.
I’m planning to follow these pointers, and maybe try my hand at another flower type or two next year. Now that I know not all annuals are “one and done,” I’m more interested in seeing what else I can grow. I wish I had understood “volunteer” plants earlier in my flower journey, but better late than never, right? I’m excited to continue learning, growing, and beautifying my yard. And if this inexperienced, busy mom can do it, you definitely shouldn’t be intimidated to try, too.
