Zinnias are an incredibly popular annual flowering plant with showy blooms. They come in a wide range of colors, bloom sizes, and heights. Whites, reds, yellows, peaches, pinks, oranges – even multi-colored varieties are available!
However, if you aim to grow a more diverse garden, you’ll need some companion plants. In this article, I’ll share 9 amazing zinnia companion plants (plus a few honorable mentions at the end). Let’s get started!

1. Cosmos

Zinnia flowers are bold and impressive, so pairing them with a more delicate bloom can help add variety to the flower garden. The wispy flowers of cosmos are gentle and beautiful, bringing a nice contrast.
Cosmos also have a different plant structure from zinnias, with a bushier, rounded shape when mature. They prefer moderately fertile soil, so don’t add too much nitrogen to the garden. If you do, you may end up with a plant stuck in the growth pattern (without any blooms).
2. Anise hyssop (agastache)

Coming from the mint family, anise hyssop has gorgeous spikes of purple flowers. This vastly different shape of flower offers much diversity in the flower garden.
The plant is a short-lived perennial, and can be used in both the flower garden and the herb garden. The leaves are very fragrant, with a licorice-like aroma and are commonly used in herbal teas.
Ironically, the flowers do not have a fragrance, but are still very attractive to bees, butterflies, and other nectar-loving pollinators. We love plants that have multiple uses, so agastache makes a great zinnia companion plant.
Similar options: Veronica, salvia, lupines.
3. Vegetables (tomatoes, peppers, climbing plants…)

It is no secret – we are vegetable gardeners at heart. However, flowers have become an increasingly important component to our veggie planning. Flowers such as zinnias bring in pollinators and predatory insects to keep other plants healthy and pest-free.
So, if you like to grow tomatoes, peppers, peas, string beans, zucchini, root veggies, or cucumbers, then consider planting some zinnias among them! Working in the garden can be hard work. So seeing a pop of vibrant color can offer some much needed joy while weeding or pruning your veggies.
4. Dill

When most people think of dill, they think of the tasty herb commonly used to make pickles. However, dill plants are also considered ornamental and beneficial as companion plants.
Personally, I also love the appearance of the broad, umbrella-shaped blooms. Again, dill is a multi-functional plant that works wonderfully among both flower and herb gardens.
Similar options: Sedum, yarrow.
5. Sweet alyssum

Alyssum is one of the superstars in our garden. It is as easy as sprinkling the tiny seeds along borders, and waiting for the plants to fill in with flowers. Not to mention, the flowers can easily last right up until the first frost (and sometimes even longer!).
Apart from providing a gorgeous, low blanket of delicate, uniform blooms, sweet alyssum also has some great benefits. Namely, alyssum plants can attract hover flies which are pest-devouring beneficial insects.
Plant sweet alyssum along the front edge of your flower beds, raised vegetable beds, or borders. The plants rarely exceed 12″ in height, and will spread and flower throughout the summer into fall.
6. Black eyed susan (rudbeckia)

Black eyed susan is a North America native biennial plant common in wildflower gardens. The plants readily self seed, so replanting is rarely necessary unless your garden is mulched.
However, this plant is worth planting from seed each year to keep the blooms coming! The pollinators will thank you, and so will your eyes. The beautiful yellow flowers surround a black center disc, creating a timeless, gorgeous bloom.
Black Eyed Susans make great zinnia companions, especially in some of the more muted zinnia colors available. I would recommend pale pink and purple zinnias to pair with Black Eyed Susans for a classic, gorgeous combination.
7. Coneflower (echinacea)

If you are looking to intermix perennials and annuals, then echinacea is a must-grow. These long-lived clump-forming perennial plants are native to North America, and offer amazing blooms through summer.
Echinacea performs well in a variety of soils, and pairs well with zinnias. The range of colors available are vast, from more natural tones like purple and white, to exotic new hybrids in greens and reds.
The only potential drawback of planting coneflowers is that they don’t flower during their first year. However, when the second season rolls around, you’ll have easy, maintenance-free blooms to go with your beautiful annual zinnias!
8. Dahlias

If you are planting a cut flower garden, then you’ll just have to plant some dahlias. Dahlias are known as the queen of all flowers, and are incredibly easy to grow.
The blooms on dahlia plants are often so large that the plants require support to prevent falling over. However, it is worth it for the amazing diversity of color, size, and height that are available.
When your dahlias and zinnias are blooming all summer, your vases will be a thing of beauty. Plus, handing a homemade bouquet to friend or loved one is special all on its own.
9. Sunflowers

While you may think of sunflowers as massive, unwieldy plants with huge blooms, they actually come in a wide variety of colors and sizes. Dwarf sunflowers can grow to just 2-3′ tall, producing dozens of vibrant blooms.
The large central discs of sunflowers make for a unique cut flower, adding interest to arrangements. The only drawback is the relatively short blooming window, as some varieties slow significantly after 1 flowering.
Honorable mentions
- Grasses. Ornamental grasses give your landscaping a natural look, providing a simple background for more showy plants. Plus, grass is a must if you plan to create a naturalistic meadow. Some ideas to consider: bunny tails, pennisetum, Mexican feather, native grasses.
- Poppies. We love poppies for their showy blooms and their seed pods in arrangements. The short lived blooms are the only drawback.

- Onions and garlic. Onions and garlic are tall, slender plants the almost resemble a thick blade of grass. Zinnias make a great companion for these somewhat bland-looking plants.
- Marigolds. Another low, mounding plant, marigolds have a similar bloom-window to that of zinnias. Enjoy a variety of colors from mid-summer through until frost!
I hope this article helps you find the perfect zinnia companion plants for your garden. We will likely never go a year without planting zinnias. And frankly, almost anything will enjoy the company of the beautiful, colorful flowers!