How tall do zinnias grow? If you intend to plant zinnias, knowing how tall the zinnias can get isn’t such a critical factor. They are easy to grow and before you know it, the explosion of colorful flowers would be in full effect 6-8 weeks after seeding. They are a great and reliable choice for newbie flower growers hoping to master a thing or two about nurturing flowers from seeds to bloom.
However, if you want to take your zinnia growing skills several notches up, knowing how tall zinnias grow is indispensable. There are several varieties of zinnias, and while all are low maintenance and easy to grow, their sizes are as varied as there are different zinnia types. For instance, You ought to know the type of zinnia to grow if you want them indoors in pots. Giant zinnias are not very suitable for indoor spaces or pots. Conversely, shorter zinnias wouldn’t deliver the desired effect as flower garden backdrops.
So strap in for a fascinating journey into the world of different zinnia varieties and how tall they can get. In the end, you’d be able to make informed decisions about the type of zinnia to grow for window boxes, cuttings, flower gardens, pots, or containers.
How Tall Do Zinnias Grow?
The sizes depend on the zinnia variety and the growing conditions. Some grow low to the soil ranging between 7 and 12 inches. These shorter varieties can also feature a mounding habit to create an overall rounded appearance.
At the other end of the zinnias, height scale are varieties that can grow to between 3 – 4 feet tall. These are sometimes grown with support stakes for best results. It is not unusual for a tall zinnia plant to also grow to between 12 and 18 inches wide producing multiple flowers on the stems.
Between the two extremes are zinnias of different sizes. This height diversity is equally matched by the diverse flower colors.
Let’s now take a look at some popular zinnias and their sizes.
Heights of 10 Popular Zinnia Varieties
Benary’s Giant Orange
This is one of the best-known tall zinnia varieties that is also famous for being very resistant to mildew. Featuring rounded, 4 inches wide full double orange blooms, the Benary’s Giant Orange can grow up to 3 feet tall and 2 feet wide.
They are similar to dahlias in appearance with a circle of tiny orange stars encircling a central disk. The stems are long and sturdy and like all zinnias bloom extensively over the growing season.
At maturity, Zahara Yellow zinnia tops off at between 12 – 18 inches tall. The plant produces symmetrical, bold daisy-like yellow flowers surrounding a ‘gold eye’ at the end of each stem. Excellent for cuttings, expect the pointy leaves to retain the vibrant green color throughout the season.
Though its texture can be understated, it blends really well into any garden. Many gardeners, to achieve effective composition, add a couple of either coarser or finer plants as companion plants.
The disease-resistant Profusion Red zinnia boasts a magnificent bunch of red flowers about 2.5 inches wide. At maturity, they form a compact, dense mound that can reach a height of 14 inches. The smallest plants in a bunch are about 8 inches tall.
The matured plant blooms with flowers resembling golden stars around a red and black center. They make excellent bouquets and with season-long flowers that bloom profusely, that is a lot of bouquets.
Giant Double Violet Queen
The large double flowers of the Giant Violet Queen zinnia can grow up to 3 feet tall and 2 feet wide in a dense mound. The flowers are a rich purple color 5 – 6 inches wide. The overlapping petals that are loosely packed. The flowers are comparatively flatter.
The long stems are perfect for cutting making them a favorite for gardeners, florists, and crafters. Experienced gardeners use these tall zinnias for sunny borders in their gardens.
The mound of the Zinnia Inca can grow to about 3 feet tall and up to 24 inches wide. At full bloom, the large flowers are about 5 inches across. They stand out in gardens with their fiery orange petals featuring graceful curls and twists.
The Inca adapts easily to a variety of climates and blooms extensively over the season.
Name after a journalist and public figure, it was first introduced over 70 years ago, the Zinnia Will Rogers grows to about 3 feet tall and 18 inches wide. The full double, brilliant cherry-red flowers are rounded. All summer long, you would get a good display of the bold and bright blooms.
Arguably the best hybrid dwarf zinnia, the Magellan Coral produces large and abundant blooms. The scarlet, fully double flowers are about 5-6 inches across at full bloom. The plant itself grows to between 15 – 18 inches tall forming a dense compact mound.
Perfect for illuminating gardens, it is also famous for comparatively quick blooming and consistent production of flowers throughout the growing season. The AAS (2005) winner is very adaptable to container cultivation and needs just minimal maintenance in the garden.
With its striking, partial, and fully double frilly flowers, the Zinderella Lilac is certainly a unique zinnia plant. With flowers about 2.5 inches across, it features elegantly packed, soft lavender and blush petals adorned with eye-catching centers.
At full bloom, the plants can grow to between 20 – 25 inches tall and about 18 inches wide. Shaped like pompoms, the flowers bloom abundantly from around mid-summer to early fall. Thanks to their long and sturdy stems, they make excellent bouquets.
This zinnia variety goes by many names like Plains Zinnia, Little Golden Zinnia, Prairie Zinnia, Golden Eye, and Rocky Mountain Zinnia. It grows the lowest to the ground forming needle-like green leaves. At about 1 inch across, the flowers are some of the smallest in the Zinnia family.
The shrub-like plants can grow up to 8 inches tall. They are very resilient and tolerant to drought and because they practically hug the ground, they make perfect erosion control plants on slopes.
The Common Zinnia is very popular among gardeners because there are different varieties with different heights, colors, and forms. Put simply, there is a Common Zinnia for everybody.
The plants can get up to 3 feet tall with several varieties topping out at just 1 foot. They also have an interesting mix of flower forms. The flowers can be single with just one or two petals leaving the center exposed, or partially double with multiple rows of petals with exposed center. A third flower form is fully double with multiple petals covering the center.
Zinnia Pro Care and Growing Tips
– Before planting zinnia, you can enrich the soil with compost. Fertilizer is not necessary.
– Save the seeds if you wish to grow a similar variety the following season.
– You can sow the seeds the following growing season in two to three weeks increments to help extend the bloom through fall.
– Train the flowers to produce longer stems by deadheading the center flowers when the plants are about three and a half feet tall.
– Plant different Zinnia varieties in a mixed border if you desire a mixture of heights and colors
– Dwarf zinnias are perfect for window boxes and containers.
– For great visual effect, grow your tall zinnia variety in clumps or rows
– If you are planting taller zinnia varieties in pots, use very large pots. Zinnias generally grow better in larger pots or containers
There are several varieties of zinnias and how they are used (bouquets, ornamental, cuttings, etc.) can depend on their various sizes. Taller Zinnia varieties are treasured for their versatility in gardens while the small or dwarf varieties grown in pots or containers, are typically found indoors, on balconies, patios, etc.
That said, no matter the type of Zinnia you choose to grow, the reward in blooms is worth the effort. And talking about effort, you don’t have to put in too much thanks to the fact that they are some of the easiest flowers to grow.