How to Grow Zinnias – The Easiest Cut Flowers for Illinois Gardens
A dad from Hoffman Estates came into Goebbert’s Farm & Garden Center last spring with his two daughters. They wanted to grow their own flowers to cut and bring inside. “Something easy,” he said. “Because I’ve never gardened before in my life.” I handed him a flat of zinnia transplants and said, “You literally cannot mess these up.” He laughed, but I wasn’t joking.
Six weeks later he sent us a photo of his girls holding armfuls of bright orange and pink zinnias they’d cut from the backyard. That’s the beauty of zinnias – they’re practically foolproof. At our garden center in Barrington, we’ve helped first-time gardeners from Schaumburg, South Barrington, Arlington Heights, and all the Northwest Suburbs grow zinnias that look like they belong in a magazine.
Why Grow Zinnias? Because They’re Summer Royalty
Once you grow zinnias, you’ll understand the hype. They actually bloom more the more you cut them. Most flowers slow down when you snip stems. Zinnias do the opposite. Cut one stem and two more grow back in its place. For folks who want fresh flowers on the kitchen table all summer, there’s really nothing better.
Zinnias pump out color from early summer right up until frost kills them in October. We’re talking four solid months of nonstop blooms in reds, oranges, pinks, purples, yellows, whites, and even lime green.
Zinnia Growing & Care Guide PDF
Picking the Right Zinnia Type
Walk into Goebbert’s in spring and you’ll notice we carry several zinnia types. Each one behaves a bit differently, so knowing what you want helps you grow zinnias that match your space and goals.
Giant or Dahlia-Flowered Zinnias (Benary’s Giant, State Fair) produce massive 4-5 inch blooms on tall 3-4 foot stems. These are the ones florists use. If you want zinnias for cutting and bringing inside, go with these. They’re showstoppers in a vase.
Profusion Zinnias stay compact at 12-18 inches and cover themselves in smaller flowers. They resist disease better than almost any other type. Perfect for borders, containers, and spots where you want tidy color without a lot of height.
Zahara Zinnias are similar to Profusion – compact, disease resistant, and incredibly heat tolerant. We recommend these for our customers who’ve struggled with powdery mildew on zinnias before. They basically shrug it off.
Giant/Dahlia-Flowered – massive blooms, best for cutting gardens
Profusion – compact, disease resistant, great for borders
Zahara – heat tolerant, mildew resistant, tidy grower
When to Plant Zinnias in Illinois
Zinnias hate cold. Hate it. They won’t germinate in cool soil, and a late frost will kill transplants overnight. Wait until soil temperatures hit at least 70°F before direct seeding. For the northwest suburbs, that’s usually late May to early June.
If you want a head start, grab zinnia transplants from Goebbert’s starting in mid-May. Transplants give you a 4-6 week jump on flowers compared to direct seeding. Most of our customers who grow zinnias prefer transplants because they get blooms by late June instead of mid-July.
How to Grow Zinnias Step by Step
Whether you’re starting from seed or transplants, here’s what actually works in our Illinois climate. Follow these steps and you’ll grow zinnias that bloom all summer long.
Sunlight – The Non-Negotiable
Zinnias need full sun – 6 to 8 hours minimum. This isn’t a suggestion. Shady spots produce wispy, leggy plants with few blooms and likely mildew problems.
That south-facing garden bed? Perfect.
The spot under the maple tree? Skip it and try astilbe or coral bells there instead.
Soil and Spacing
Zinnias aren’t fussy about soil. Average garden soil works fine as long as it drains well. Mix in some compost at planting time and you’re good. They’ll grow in the clay soil around Hoffman Estates and the sandy garden spots near Algonquin without complaint.
Spacing matters more than people think. Plant zinnias 8-12 inches apart for compact types and 12-18 inches for tall varieties. Air circulation between plants is your best defense against powdery mildew, which is the one issue that bugs zinnia growers around here.
Planting Steps
- Pick a full sun spot with well-drained soil
- Work in a few inches of compost
- Dig holes same depth as the transplant pot, spaced 8-18 inches apart
- Set plants at the same level they were growing in the container
- Water deeply right after planting
- Mulch lightly around plants – keep mulch away from stems
Watering and Feeding Zinnias the Right Way
Here’s where most people mess up when they try to grow zinnias. They water from overhead with a sprinkler and soak the leaves every evening. That’s asking for mildew and fungal problems. Always water zinnias at the base of the plant, not from above. A soaker hose or drip irrigation works best. Morning watering is ideal so any splashed leaves dry quickly in the sun.
Once established, zinnias handle dry spells better than you’d expect. They’re not quite as drought-tolerant as sedum, but they don’t need daily watering either. Deep soaking twice a week beats light daily sprinkling every time. A customer from South Barrington waters her zinnia bed only when it hasn’t rained in 5 days, and her plants look incredible.
Fertilizing Zinnias
Zinnias aren’t heavy feeders. Too much nitrogen makes them grow tall and leafy with fewer flowers. A balanced slow-release fertilizer at planting time carries them through most of the season.
If blooms slow down in August, a light dose of bloom-booster fertilizer (high phosphorus) can perk them back up. We sell a few options at Goebbert’s and can help you pick the right one.
Cutting Zinnias for Bouquets
This is the best part about growing zinnias. The more you cut, the more they bloom. It’s like the plant gets competitive with itself. Here’s how to cut them right:
- Cut stems in the morning when they’re fully hydrated
- Use sharp scissors or garden snips – clean cuts heal faster
- Cut just above a leaf node so new branches sprout from that spot
- Put stems in water immediately after cutting
- Change vase water every 2-3 days for longest life
Dealing With Powdery Mildew and Other Zinnia Problems
Powdery Mildew – This is the number one complaint we hear from folks who grow zinnias. White powdery spots on leaves, usually showing up in late summer when humidity spikes. Good news: it looks bad but rarely kills the plant. Space your zinnias for air flow, water at the base instead of overhead, and choose resistant varieties like Profusion or Zahara. Our disease-resistant flower selections on the blog cover more options.
Japanese Beetles – Yep, they love zinnias just like they love hardy hibiscus. Hand-pick them early in the morning when they’re sluggish. Drop them in soapy water. Neem oil spray works as a deterent too. The damage is cosmetic – ugly, but your plants will survive.
Leggy Growth – Not enough sun, period. Zinnias stretch toward light when they don’t get enough. Pinch the growing tips when plants are 6 inches tall to encourage branching. This gives you bushier plants with more flower stems.
Best Ways to Use Zinnias in Your Garden
If you grow zinnias as workhorses in the garden, you’ll love their flexibility. Tall varieties make amazing back-of-border plants behind shorter annuals like petunias. Compact types work great along walkways or in containers on your deck. Mix zinnia colors together for a cottage garden feel, or stick with one color for a more polished look.
Pair zinnias with other sun-loving plants that bloom at different times. Bee balm overlaps with zinnias in mid-summer. Purple coneflowers and black-eyed Susans create a pollinator paradise alongside them. A landscape designer from Arlington Heights told us she plants zinnias in every client’s garden because “nothing else gives you that much color for that little money.”
Zinnias for Cut Flower Gardens
If you grow zinnias mainly for bouquets, plant Benary’s Giant or Oklahoma varieties. Grow them in rows spaced 12 inches apart for easy picking. A woman from Algonquin grows three 10-foot rows and brings fresh arrangements to her book club every week all summer. Cost per bouquet? Basically free after the initial planting.
Zinnias as Pollinator Magnets
Butterflies absolutely love zinnias. If you grow zinnias near your vegetable garden, monarchs, swallowtails, and painted ladies will flock to the blooms. You’ll attract pollinators that help your tomatoes and squash produce more fruit too. It’s a win-win that our pollinator garden guide explains in more detail.
Grow Zinnias From Seed or Buy Transplants?
Both work when you want to grow zinnias. Direct seeding is simple – push seeds half an inch into warm soil, water, and wait about a week. Thin seedlings once they’re a few inches tall. Seeds are cheap, and zinnias germinate fast in warm soil. The downside? You wait longer for flowers.
Transplants from Goebbert’s give you a real head start. Our plants are already 4-6 inches tall and ready to take off. You’ll be cutting flowers in June instead of waiting until mid-July. For impatient gardners (no shame – we get it), transplants are the way to go.
Shop Zinnias at Goebbert’s This Spring
We carry a fantastic selection of zinnia transplants every spring at Goebbert’s Farm & Garden Center in Barrington. Our inventory peaks from mid-May through June – that’s when you’ll find the widest range of colors and types. We stock everything from towering Benary’s Giants to compact Profusion varieties, plus unique colors you wont find at chain stores.
Our team knows how to grow zinnias in our Illinois climate. We deal with the same clay soil, the same humidity, and the same Japanese beetles you do. Bring your questions. Show us your garden photos. We’ll help you pick the right zinnias wether you’re in Barrington, South Barrington, Schaumburg, Arlington Heights, Hoffman Estates, or Algonquin.
Stop by this spring and let’s get your garden bursting with color. That dad from Hoffman Estates? His daughters are already asking when they can come back for more zinnias this year.