One of the superstars of the annual cutting garden, zinnias are also great for growing in pots on your patio or balcony. You can even try growing these tropical annuals indoors as short-lived houseplants!
Potted zinnias will last for several months before they stop flowering and die. They usually take 60 to 70 days to flower from seed. Individual blooms last for a week or two, and the plants will pump out a continuous display of brilliant blooms until they die in the autumn.
How to Care for Potted Zinnias?
- Plant seeds in warm, moist soil that will drain well, with plenty of added organic matter such as well-rotted compost.
- Set the containers in a location where they will get at least 6 hours a day of full sun.
- Water when the top 1 inch (2.5cm) of soil is dry. Never let the plants sit in standing water, which will rot the roots.
- Feed once or twice a month with liquid fertilizer diluted to half strength.
- Cut out the stems of spent flowers down to the base of the plant.
Can Zinnias Survive the Winter in Pots?
Zinnias will not survive the winter in pots, even in tropical or sub-tropical regions. They are true annuals and will die in the fall when they have finished their life cycle. However, they are easy to start from seed, so just save seeds from your favourite varieties to plant the following spring.
Potted Zinnias Temperature Tolerance?
Potted zinnias are extremely sensitive to cold temperatures. In fact, even when temperatures are reliably above freezing but fall below 50°F (10°C) at night, it’s too cold to plant zinnia seeds outside. They need warm soil and mild temperatures to ensure success. Frost will kill them.
Zinnias prefer temperatures between 74–84°F (23–28°C), but will continue to flower even when temperatures exceed 90°F (32°C). Just keep them well watered to reduce stress in really hot weather.
Do Potted Zinnias Come Back Each Year?
Potted zinnias will only last one summer, no matter how much you coddle them. They are annual plants that sprout, flower, set seed, and die back as the summer turns to fall.
Enjoy them while they last, and then look forward to planting seeds next spring for another year of brilliant blooms!
When Should You Plant Zinnias in a Pot?
Zinnias do not respond well to the root disturbance of transplanting, so it’s usually recommended that you direct seed them in their permanent containers.
If you have the room, you can keep those pots indoors under grow lights to get an early start on the season. About 6 to 8 weeks before the last frost date, tuck the seeds into loose, well-draining soil in a pot with good drainage.
You can also start seeds in peat pots or pellets that can be planted without disturbing the roots. Only plant them outside when things have warmed up enough that temperatures stay above 50°F (10°C) at night.
Be sure that you harden them off when you first bring them outdoors. Start them off in a shady spot, increasing their exposure to sun over a week.
If you don’t want to start them yourself, zinnias are a popular annual at garden centres, where you will have lots of varieties to choose from.
How Long Do Potted Zinnias Take to Grow?
Once you have planted the seeds, zinnias take between 60 to 70 days to bloom. Once they start, the flowers should continue non-stop until fall.
How Long Will Potted Zinnias Last Inside?
While they are usually grown outdoors, you can try growing potted zinnias as houseplants. Even protected from cold temperatures, however, they will die after several months as they complete their natural life cycle.
You will need lots of light to grow potted zinnias indoors; unless you have south-facing windows with a minimum of 6 hours of direct sun, grow lights are an absolute necessity for zinnias.
However, you should be able to move your potted zinnias out from under the grow lights for a few days at a time so that you can enjoy the brilliant flowers in various spots in your home.
You will also need to carefully choose the varieties to grow indoors. While zinnia plants that grow to 3 or more feet tall may work in large containers outdoors, dwarf varieties are better suited to indoor cultivation.
With their glorious profusion of brilliant blooms all summer long, it’s easy to create a beautiful show of zinnias in containers. Even if you just have a sunny balcony or south-facing window, zinnias are a cheap and easy way to fill your pots with flowers!
See how long other potted plants last:
- How Long Do Potted Tulips Last?
- How Long Do Potted Calla Lilies Last?
- How Long Do Potted Hydrangeas Last?
- How Long Do Potted Geraniums Last?
- How Long Do Potted Daffodils Last?
- How Long Do Potted Pansies Last?
- How Long Do Potted Hyacinths Last?
- How Long Do Potted Gerbera Daisies Last?
Janice is a retired High School teacher who is spending her leisure years keeping busy with all sorts of projects. Aside from freelance writing, she’s an enthusiastic amateur chef, home wine maker, and tends a large raised-bed vegetable garden, while at the same time running a Bed & Breakfast.