10 Perfect Illinois Annuals

Wondering what to plant in your garden? It all depends on your location. In Illinois, you need plants that tolerate both cold and warm weather.

10 Perfect Illinois Annuals

This article lists 10 perfect Illinois annuals, such as Dahlias, Impatiens, Vincas, Snapdragons, and Cosmos.

Plant any of them for a colorful garden that blooms with life for months. Read on for the best annuals to grow in Illinois, their features, and requirements.

1. Dahlia


Dahlias come in multiple varieties. They feature huge blooms and long stems, ranging from 1–5 feet tall.

This flower requires moist but well-drained soil. It grows best in direct sunlight. Still, it can survive in the shade with a little extra care.

Generally, Dahlias are perennials, but not in Illinois. Although this flower is hardy in USDA zones 3:10, it can only tolerate the winters in hardiness zones 8:10. You should plan only to grow it as an annual that blooms in the summer.

2. Impatiens


This plant blooms into beautiful flowers with bright colors. It grows between 8–24 inches. However, its growth depends on the amount of sun it receives.

Although Impatiens thrive both in shade and sunlight, they grow taller and bloom heavier if exposed to direct sunlight.

Impatiens come in various colors, including red, pink, white, and orange. They’re suitable for any type of garden or even inside your house.

This flower thrives in hardiness zone 3:10, which makes it a perfect fit for your Illinois garden. It requires constant watering, especially during hot days.

3. Vinca


Vinca is a beautiful flowering plant that blooms all year round. It withstands the heat of the sun and can even tolerate drought.

This large flower features a variety of colors, such as:

  • red
  • coral
  • pink
  • white
  • lavender
  • peach

It can reach 10–15 inches tall and 1–2 inches wide.

Plant this annual during the warm season in well-drained soil. It thrives in hardiness zones 7:9, which means it may survive the winter in Illinois.

4. Snapdragon


Snapdragon is a classic annual plant every garden should have. It’s easy to grow and doesn’t require much care. In fact, it can bloom all summer if the weather is warm enough.

This flower thrives in hardiness zones 7:11. Therefore, it prefers sunny areas but can tolerate the cold.

There are two primary varieties. The first can grow as tall as 36 inches, and the other is a small mounding plant of 1–2 inches that blooms profusely.

These flowers come in different colors, such as:

  • white
  • orange
  • pink
  • lavender
  • yellow
  • bronze

5. Cosmos


Cosmos look a lot like daisies. They can grow 3–4 inches wide and reach 2–5 feet tall.

They feature a yellow center surrounded by jagged-edged petals. These flowers come in various shades, including red, white, and pink.

This annual is hardy in zones 2:11, which means it may tolerate the cold winters of Illinois. It thrives in partial or full sun.

To allow lavish growth, plant these flowers about 12–15 inches away from each other. You should also add some organic material to the soil to ensure healthy growth.

6. Geranium


Geraniums grow into clusters with a diameter of about 4–5 inches. They come in pink, red, white, crimson, and salmon.

This flower thrives in hardiness zones 3:9. Therefore, it can survive the weather in Illinois.

Generally, it prefers sunlight. For a bushy bloom, expose your Geranium to 4–6 hours of sunlight daily.

You can plant Geraniums in gardens or within containers. It’s best to water this plant thoroughly, but give the soil some time to dry between waterings.

7. Spider Flower


These flowers feature round heads of about 6–7 inches in diameter. They get their name due to their long spidery stamens. They also feature long-loaded seed capsules.

Typically, spider flowers come in several colors, such as lavender, pink, and white. The length of this plant ranges between 2–5 feet.

Spider flowers are hardy in zones 2:11. They grow best under direct sunlight and in moist, well-drained soil. Although this plant tolerates drought, it thrives better if watered.

8. Portulaca


Portulaca blooms into a flower that resembles a rose. It’s a small bloom with a diameter of 1–2 inches. It comes in a range of colors, including:

  • Salmon
  • Scarlet
  • Rose
  • White
  • Yellow

This plant features fleshy, narrow leaves that favor sunny areas. It thrives in hardiness zones 2:11. It grows best in hot, dry areas.

Interestingly, Portulaca is an ornamental garden plant that can be edible. It’s usually used to feed chicken and some larvae species.

9. Tobacco


Tobacco blooms into small flowers with a diameter of 1–2 inches. This flower is tubular with five lobes. It can grow between 10–18 inches tall.

This scented flower comes in various colors, like green, pink, and white. It also attracts pollinators such as butterflies and moths.

The flowering tobacco grows in hardiness zones above 5. Thus, it favors warm weather and can tolerate heat and drought.

This makes it easy to grow. We recommend planting this seed in the early spring, right after the frost.

10. Black-Eyed Susan

Black-Eyed Susan

The black-eyed Susan is a pretty flower with a black central part. Typically, it comes in shades of yellow, rust, and orange. The annual variety reaches up to 24 inches wide and 25 inches tall.

This plant thrives in hardiness zones 3:10. You should plant it in a sunny spot in your garden during the early spring.

Typically, this plant blooms from June to September. It attracts pollinators of all types.

Avoid watering the leaves of the plant. Instead, direct all water into the soil. This way, you avoid fungal diseases.


So what annual to grow in Illinois? Due to its varied weather, Illinois requires hardy plants that can thrive in the heat of summer and tolerate the cold of winter.

Among the 10 perfect Illinois annuals are Black-Eyed Susan, Tobacco, Portulaca, Spider Flower, and Geranium. Plant any of these annuals to add fragrance and color to your garden.