The spacing of your zinnias will depend on the variety you’re planting and its intended use. Smaller zinnia varieties used as a border or containers may be planted as closely as 6 inches apart. However, larger varieties with huge flowers may require up to 18 inches of space between each plant. Consider increasing the distance between your zinnias if you live in a hot, humid region, as this will promote air circulation and prevent disease.
If you are growing zinnias from seed for bouquets, space the seeds about nine inches apart. Growing flowers in a small space like this help to promote the development of tall, straight stems and facilitates their subsequent harvest.
Conversely, if you’re growing zinnias for in-garden enjoyment or to lure in pollinators, you should give the plants greater room. Since they won’t be pruned as often as those grown for cutting, a 12-18 inches spacing is fine.
Zinnias with shorter variations are great patio container plants. Keep in mind to consider how widely the cultivar you are planting will spread. Spread refers to the plant’s final, mature width. Generally speaking, the smaller or dwarf varieties of zinnias must be planted at least 6 inches apart from one other. Consider planting just one zinnia plant per pot using a relatively tiny container (6 to 10 inches wide).
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For Commercial Production
Narrow spacing is superior for flowering since it avoids side branching, but single harvesting is optimal. Wide spacing at 2′ between rows and 6″ within the row is better for multiple harvests. In Florida, plant spacing of 6″ between plants was sufficient for summer yield.
Depending on the variety, space plants 4 to 24 inches apart. Many common cultivars are spaced at an interval of 6 inches within the row and 2 feet between rows. See the back of the seed packet for a specific variety of information.
Sow zinnia seeds only approximately 1/4-inch deep.
Most zinnia varieties will produce seedlings within four to seven days. Still, it will be several weeks to months before the flowers appear (depending on the planting site and climate).
When seedlings reach three inches in height, space them six to eighteen inches apart to improve air circulation. This minimizes the possibility of powdery mildew growing.
Zinnia Planting Tips
Plant zinnias after the last forecast frost, as they cannot endure freezing temperatures. Typically, zinnias should not be planted outdoors until the soil has reached at least 70-80°F (21-27°C). If you want a head start, you can start them approximately 4 to 6 weeks before your latest projected frost date.
Plant zinnias anywhere between 6 and 18 inches apart. Small types of bedding plants that do not exceed 8 inches in height can be placed 6 to 10 inches apart. Larger types that can grow to a height of 4 feet should be planted 12 to 18 inches apart.
In a cut flower garden, you space enormous ‘Benary’s Giant’ zinnias 9 inches by 9 inches apart in a 9-by-9 grid. This produces longer, straighter stems. For reference, you can generally plant these at least 12 inches apart in the landscaping. Zinnias can be planted indoors or outdoors. Outdoor planting might be advantageous, particularly if you have preserved many zinnia seeds from a previous crop.
Direct Outdoor Sowing
Be sure to plant seeds at least 14 inches deep when directly sowing them outdoors. They can be planted in a furrow, and you can thin the seedlings to the proper spacing as they sprout. You can scatter seeds, but to encourage seed-to-soil contact, you must rake them into the ground. Be mindful that your germination may be less than usual. If you are spreading your seeds, you will probably need to trim out your seedlings. You’ll naturally have less control if you let your zinnia reseed itself.
The act of uprooting and eliminating newly emerging seedlings is known as thinning. This guarantees that the plants are spaced correctly throughout your whole planting. When direct sowing into the garden, gardeners occasionally overseed.
They do this because they know that some seeds may not germinate for various reasons. Later, they might remove seedlings that are unnecessary. Thinning your plants might be painful. However, if you keep your plants too close together, you’ll get weaker plants that fight for moisture and sunshine.
Planting Seeds Indoors
Make sure to plant the seed in your cell tray or little pots at least 14 inches deep if you’re starting seedlings indoors. I prefer to use a pencil to make holes in the cells, place the seeds inside, and then cover and duster the area with vermiculite. Heat mats will undoubtedly help you speed up germination.
Popular Zinnia Varieties
Here are a few well-known kinds, together with the suggested spacing for each:
“Aztec Sunset” Zinnias
They have tiny, 1 to 2-inch red, yellow, orange, and bicolor orange and maroon flowers and can reach heights of up to 2 feet. This type should be placed 10 to 12 inches apart.
“Benary’s Giant” series
With 4 to 5-inch blooms in 13 different hues, they will reach heights of 3 to 4 feet. Place the seeds of this type 12 to 18 inches apart. Spacing for cut flower measures from 9-10 inches.
“Crystal” Series Zinnias
They grow to a maximum height of about 10 inches and have a single-petaled variety with orange, white, and yellow flowers. You can space these zinnias anywhere from 6 to 10 inches apart.
“Oklahoma” Series Zinnias
They appear in various hues, but the blooms, which have a diameter of only around 2 inches, are significantly smaller. These plants should be spaced 10 to 12 inches apart. Spacing for cut flower measures from 9-10 inches.
“Queen” Series Zinnias
They have blossoms that fade into lime and have vintage rose, orange, and blush hues. The zinnias need to be placed 10 to 12 inches apart. Spacing for cut flower measures from 9-10 inches.
It features center-ringed mahogany blooms that are brilliant, cheery, and either orange or yellow. This cultivar should be placed 10 to 18 inches apart.
It’s a magnificent, large, well-branching zinnia with rose color. Place the seeds of this type 12 to 18 inches apart.
More Zinnia Varieties and Plant Spacing:
|Variety||Height||Spacing for landscaping||Spacing for cut flowers|
|Art Deco Mix||Tall/ 24-30 inches||12-18 inches||9 inches|
|Magellan series||Tall/40-50 inches||18 inches||9 inches|
|Preciosa series||Dwarf/10-12 inches||12-18 inches||N/A|
|Profusion series||Medium/ 12-18 inches||12-18 inches||N/A|
|Sunbow Mix||Tall/ 24-30 inches||12-18 inches||9 inches|
|Zinderella series||Tall/ 24-36 inches||18 inches||9 inches|