Growing zinnias is one of the best ways to add a rainbow of color to your flower garden. Brighten up your landscaping this year by learning how to grow zinnias from seed.
I grow zinnias for several reasons, but the main reason is that their spectacular summertime show of beautiful, colorful blooms last a long time- until frost! Pollinators love zinnias, too, so they can be enjoyed by gardeners well after summer thanks to the flurry of activity happening around the flowers. In this post I’ll help you learn how to grow zinnias so you can create a pollinator haven, enjoy cut flowers, and add stunning pops of color to your growing space.
Finding the Best Spot to Grow Zinnias in Your Garden
Zinnias are native to Central America, which means they can handle the summer heat and need plenty of sun each day (6 to 8 hours.) If you’re unsure of the best location to plant your zinnias, you should do sun mapping to find that ideal space. You can find more information for how to do sun mapping in this post.
Once you’ve found the best space to grow your flowers, it will be time to get to know your soil. If the texture is sandy or full of clay, you will need to add compost to achieve a loamy texture.
How to Choose a Variety of Zinnia to Grow
There are many varieties from which to choose- there is a zinnia for everyone! Do some research and make some decisions on these four important things:
- First, decide what size of zinnias your garden can accommodate: some varieties grow in a low mound, and some can grow up to 4 feet tall.
- Zinnias are grown as annuals from zones 2 to 11. Note the length of time until the zinnias reach maturity, most varieties take about 2 months from seed to flower. Choose a variety that fits your growing season.
- Now for the fun part- decide what colors you’d like to see in your garden! Zinnias come in all colors of the rainbow and can be combined in numerous ways. You can easily find shades of red, yellow, orange, pink, purple, white, and even green flower heads.
When and How to Plant Zinnia Seeds
The best time to plant zinnia seeds is on or after the average frost date for your growing zone. At that ideal time (and after finding the best location with ample sunlight and preparing the soil,) follow these steps:
- Spaced the proper distance apart, make holes 1/4 to 1/2 inch deep. The spacing requirements should be noted on the seed packet of the variety you purchased. If it isn’t, check the seed company’s website for more information about your specific variety. Spacing is important for zinnias to ensure maximum airflow between the plants.
- Plant your seeds and lightly cover with soil. Water them and keep them moist until they sprout.
- After planting, add mulch around the hole (don’t cover it) to help the ground retain moisture and suppress weeds. Pull mulch in around the stem as the seedling grows.
How to Care for Zinnias As They Grow
Watering Zinnias
Zinnias need about 1 inch of water each week (including rainfall) while they’re getting established. Overwatering will create issues with the plant like yellowed leaves or root rot. It can also cause foliage diseases like leaf spot, powdery mildew, or wilt.
When you water your zinnias, avoid getting the foliage wet by watering only at the base of the plant.
Staking Zinnias
The taller varieties of zinnias will benefit from the use of stakes or cages to keep them standing properly. If you are growing zinnias in rows, the plants will benefit from the use of horizontal netting to keep them growing upright.
Problems with Zinnias
According to the University of California’s Department of Agriculture & Natural Resources Integrated Pest Management program, zinnias can fall victim to plenty of pests:
- aphids
- broad mites
- earwigs
- leaf miners
- spider mites
- thrips
- true bugs like boxelder & stink bugs
- and whiteflies.
Don’t let pests steal your garden’s thunder! Deter them by interplanting your zinnias near plants that will repel them. Consider planting cosmos, chives, cilantro, thyme, or basil. You can find more companion planting ideas in this post.
Zinnias can withstand the occasional drought, but too much moisture is not a good thing. Yellowed leaves, root rot, wilting, powdery mildew, blight, and leaf spot are all problems that are caused by too much moisture. Try your best to keep watering consistent throughout the growing season.
Tips for Cutting Zinnias
Best Time to Cut Zinnias for a Vase
The best time to cut zinnias for a vase is on a dry day in the early morning or the evening. For the longest lasting display, choose flowers that have just begun to open.
How to Cut Zinnia Stems
Cut the stem of the flower at a 45° angle at the desired height. Immediately put it into a bucket or the prepared vase that has been filled with room-temperature water. Do not let the base of the stem dry out.
Caring for Zinnias in a Vase
Let’s keep those flowers looking their best, shall we? Zinnias will look their best in a vase for 5-7 days. Before arranging the flowers, fill the vase with room-temperature water. Remove excess foliage so that the leaves will not sit to rot in the water. After arranging your beautiful stems, change the water at least every other day and keep your flower arrangement away from drafts and out of direct sunlight.
What to Do with Zinnias After Blooming
Say goodbye to your beautiful blooms when that first hard frost hits your area! After that time, you have two options.
One, you can postpone cleaning up your garden until springtime and let them continue stand through the winter. Birds will appreciate the seed heads and insects will enjoy another option for creating a home for the winter. Check out this article from the Xerces Society to learn more about providing nesting & overwintering habitats for pollinators and beneficial insects.
However, if you’d rather not look at and deal with dead plants over the winter, your second option is pull them out by the roots. Rake mulch over the growing area and discard the plant or put it in your compost area.
FAQ
Do zinnias do better in pots or in the ground?
Zinnias grow well in the ground and in pots! If you’d prefer to grow them from seed in containers be sure to choose a low-growing variety. Your container should be large enough to provide enough room for the roots and the soil should be well-draining.
How many zinnia seeds do you put in each hole?
Plant 2-3 seeds in holes that are about 1/4 to 1/2 inch deep. Once the seedlings reach about 3 inches tall, thin them to just one seedling per hole. This will ensure that you have proper spacing and airflow between your plants.
Do zinnias need a lot of space?
Depending on its mature size, each plant will need between 9 to 12 inches of space. Read the seed packet before planting so you know the needs of your specific variety.
How do you keep zinnias blooming?
Zinnias are low-maintenance and don’t require deadheading, but removing spent blooms on your plant will encourage fresh growth.
How do you deadhead zinnias?
Deadheading zinnias is simple. All you need to do is make a clean cut on the spent stem just above a set of healthy leaves.
Related Articles
- How to Create a Bee Garden
- How to Remove Grass to Prepare for a New Garden (No Digging!)
- How to Grow Sunflowers
Save This Post!
