True annuals and plants that we grow as annuals (considered tender perennials in southern regions) cannot survive cold winter temperatures. But there's no need to say farewell to these plants forever! Many “annuals” can be brought inside, even tender plants that need a winter dormancy period.
But the species that are "true annuals" can't be overwintered using either of these methods, as they are genetically programmed to flower and die in a single growing season. If you try to bring such a potted plant indoors, it will simply turn brown and die as it completes its lifecycle.
Your annuals need lots of sunlight in order to survive the winter season, and so placing your plants in the brightest spot of your home will ensure they thrive. A windowsill that receives plenty of bright light will do!
In warmer zones they can be perennials--or at least live for a couple of years--but in colder zones these are plants are usually allowed to die with the first frost. One benefit of overwintering annuals is saving money.
Most annuals like soil slightly and evenly moist 2 or 3 inches down. When you water, if possible, water the soil, not the plants. Many annuals, especially petunias, object to wet leaves and petals. Set the hose on the ground on a drizzle or use soaker hoses.
Most potted or hanging plants, like petunias, are fine as long temperatures don't dip below 39 degrees, and especially if the temperature doesn't dip to the freezing mark.
An annual plant completes its life cycle in one year.
Once seed matures, the life cycle is complete, and the annual plant dies. Other annuals have their lives cut short before they can set seed because frost arrives.
Overall even flowers can tolerate light freezes (low 30s to upper 20s °F) and even a little snow. Record cold temperatures (below mid to upper 20s) will damage or destroy many of the flowers of early blooming varieties. The foliage of fully emerged spring-flowering bulbs like tulips and daffodils can also be damaged.
Since annuals only have one season to create seeds for the “next generation”, they tend to have a long bloom period. They seek as many opportunities to create seeds. And you can make the most of it by removing the flowers as they fade. This will encourage them to bloom again so they can make more seeds.
Indoor air can be very dry in winter due to heating, so your plants will appreciate extra humidity from a humidifier, misting, or placing the pot on a saucer with pebbles and water (make sure the bottom of the pot is not sitting in the water).
To extend the beauty of your garden into autumn and put some color back into your landscape, consider planting some cold-tolerant annuals. Many of these can take temperatures to 20° F. As our seasons change, so can your garden by highlighting these beautiful tough plants in your beds, borders and containers.
Many gardeners grow flowers in their outdoor beds from springtime until fall. But, when winter's cold winds blow, it becomes challenging to keep outdoor blossoms coming. Fortunately, you can enjoy the beauty of flowering plants all year long, by creating an indoor flower garden.
Steps To Care For Petunias in Winter
The plant will need to be brought inside in the winter in colder regions. Petunias can be allowed to go dormant, or you can try to keep the plant actively growing, but be aware that it can be hard to prevent dormancy.
The 242-year-old Eastern Cape cycad has been growing in a pot since 1775. Most botanists agree there are no predetermined lifespans of indoor plants.
Perennial plants regrow every spring, while annual plants live for only one growing season, then die off.
Some cool-season annuals can tolerate soil temperatures as low as 45 degrees Fahrenheit; however, most cool-season annuals will grow best in soil temperatures at 65 degrees Fahrenheit or warmer.
Cover Plants – Protect plants from all but the hardest freeze (28°F for five hours) by covering them with sheets, towels, blankets, cardboard or a tarp. You can also invert baskets, coolers or any container with a solid bottom over plants. Cover plants before dark to trap warmer air.
Flowers are happiest in temperatures of 40-50 degrees. Most of my flower coolers are about 36 degrees.
You may be overwatering. Make sure your container has adequate drainage and then cut back on watering. Use pruning snips to trim away dying foliage. Yellow leaves can also mean the plant is rootbound and needs to be moved to a bigger pot with drainage holes.
Remove Most Annuals
In general, these plants are easy to spot because after the first hard frost, many of them, including impatiens, begonias, and coleus, have withered and turned brown. If the spent foliage and blossoms on these plants are free of mold and disease, we put them in the compost pile.
Annuals, with their shallow roots, will typically need water every single day. Especially if they're in the hot sun. On those hot sunny days water your annuals twice a day. Don't let your annuals dry out, especially if they're in a container.
Planting Annuals Pots
Use containers with good drainage at the bottom and large enough not to be top heavy as the plants grow to their full size. A soil-based potting mix with added perlite will keep containers and hanging baskets draining well and lightweight.
If you're wondering at what temperature threshold you should be bringing your plants, there's a short answer: when nighttime temperatures reach 45 degrees (F), it's time to bring your plants indoors.