Marigolds come in beautiful shades of orange, yellow, and red, but if you live in an area that gets too cold in the winter months, you may want to reconsider planting them. Marigolds are not frost hardy and they grow all year in areas where the temperature never gets below 40 degrees Fahrenheit.
Key Takeaways
- Marigolds are not frost-hardy and will die when the temperature drops below 32 degrees Fahrenheit.
- To protect your marigolds from frost, make sure they are well-watered and consider covering them with a frost cloth or mulch.
- If you live in a colder climate, consider growing other cold-tolerant annual flowers in addition to marigolds.
How to Protect Marigolds From Frost
Check out these easy tips to protect marigolds from frost.
1. Make Sure They’re Well-Watered
Before the very first frost, make sure your marigolds are well-watered. Water keeps the soil insulated and warm, so if they’re not well-watered they’ll be less likely to survive the frost.
2. Place Your Marigolds Under a Lamp
Marigolds do best in warm temperatures, so when it’s cold outside, consider placing them under a lamp with a 100-watt light bulb to keep them warm enough, but don’t let the bulb touch any area of the plants themselves.
3. Use Mulch
Placing mulch around your marigolds helps keep them a lot warmer, which in turn increases the likelihood they’ll survive the winter months.
When to Protect Marigolds From Frost
First of all, you should never plant your marigolds outdoors until you are certain that no more frosts will occur. Let’s say you live in an area that has frosts late in the year. In this case, it is recommended that you plant marigold seeds indoors roughly 6-8 weeks before you expect the very last frost to occur.
As soon as you learn that a frost is expected, either cover the plants with a plant cover or bring them indoors if they are planted in pots. Each time you expect a frost to occur, it’s crucial that you take steps to protect your marigolds.
Check out this video for tips on how to plant marigolds.
4 Tips to Protect Marigolds Over Winter
To take good care of marigolds throughout the winter months, the first thing you need to do is learn to protect them from cold and frost. Here are the steps to take to increase the odds of their wintertime survival.
1. Location
In the wintertime, marigolds need sunlight, so the best thing to do is place them near a window that receives a minimum of 6 hours of sunlight per day. The sunlight is important for two reasons: it helps the plant grow and thrive, and it helps keep the color of the plants nice and vibrant.
2. Add Mulch
There are all different types of mulch, but marigolds should get two to three inches of mulch on top of their soil to keep them a little warmer when it’s cold outside.
Shredded bark or even hay make for a good marigold mulch, but keep the mulch five or more inches away from the stems of the plants. Otherwise, rotting could occur.
3: Water Twice a Week
Not only should you water your marigolds twice a week, but you should also water them deeply. By this, we mean that when you water the plants, the water should go two inches into the soil.
If you stick your finger two inches into the soil and feel dryness, it means your marigolds need a little more water.
Step 4: Promote Regrowth
To promote regrowth of your marigolds, you’ll need to remove anything that is dead or wilting from the bottom of the plants. Otherwise, their growth may be stunted.
3 Ways to Keep Marigolds Growing During Winter
Marigolds usually bloom from early summer until the first frost occurs. They usually don’t bloom in cold weather but are dormant instead. Still, there are things you can do to make sure they stay healthy in the winter, including:
1. Keep Them in the Right Environment
Marigolds do best in a warm dry environment with temperatures that never get below 40 degrees Fahrenheit. If you live in a very cold area, it’s best to plant them in planters so you can bring them indoors in the winter.
2. Never Expose Them to Frost
Never expose marigolds to the first frost because it can either kill them or make them weaker, which means they may not survive the winter.
3. Keep Them Watered
Even in the winter, marigolds have to be watered. Unless they’re dormant, you should deeply water them down to two inches twice a week.
How Cold Is Too Cold for Marigolds?
Marigolds do not do well in temperatures below 40 degrees Fahrenheit. Many marigolds, including healthy ones, die once the temperature gets down to freezing (32 degrees). This is especially likely if the cold temperature is combined with cold windy weather.
How Does Frost Affect Marigolds?
Frost usually kills marigolds, especially if the weather in general is very bad. If the flowers are sturdy and the weather isn’t that windy, they may survive a light frost, but the bottom line is, you’re always taking a chance with your marigolds once the temperatures get down to 32 degrees.
They may survive one frost or they may die on the first frost. You never know, but this is a good reason to protect your marigolds from the frost every single time it gets cold.
Will Marigolds Come Back After a Freeze?
Marigolds may or may not come back after a freeze, but they cannot continuously do this. After one or two exposures to frost, especially if the temperature is below freezing, it’s unlikely they’ll survive more than that. In most cases, marigolds will need to be replaced at the end of the season.
They will not just regrow a year after you plant them. So while marigolds might possibly come back after a freeze or two, it’s unlikely they’ll last any longer than that. Plan to replace your marigolds once a year even if they are not exposed to frost, but especially if they are.
Conclusion
Marigolds thrive in a warm dry environment, and they do not do well in temperatures below 40 degrees. To help them look their best, protect them from all frosts and make sure you replace them every year at the end of the season in order to look forward to more.
Frequently Asked Questions
Are marigolds perennials?
No, marigolds are not perennials. They are annual plants, which means they complete their life cycle in one growing season. However, they can self-seed and come back year after year, but they are not considered perennials.
What temperature is too hot for marigolds?
Marigolds prefer warm temperatures between 70°F and 75°F. Temperatures higher than 85°F can cause damage to the plant, including wilting and leaf drop. If you live in a hot climate, it is best to plant marigolds in an area with partial shade to protect them from the intense heat.
Will marigold seeds survive winter?
Marigold seeds can survive winter if they are stored in a cool, dry place. However, if the seeds are left outside, they may not survive the cold temperatures and moisture of winter. It is best to collect marigold seeds before the first frost and store them in a sealed container until the following spring.
Are zinnias cold hardy?
Zinnias are not cold hardy and cannot tolerate frost. They are annual plants that thrive in warm temperatures and bright sunlight. If you live in a cold climate, it is best to plant zinnias in the summer and enjoy their vibrant colors until the first frost.
What is the frost tolerance of calendula?
Calendula, also known as pot marigold, is a hardy annual that can tolerate light frost. However, prolonged exposure to cold temperatures can damage the plant and reduce its lifespan. It is best to protect calendula from frost by covering it with a frost blanket or bringing it indoors during cold snaps.
Can marigolds tolerate cold temperatures?
Marigolds can tolerate cool temperatures between 50°F and 60°F, but they are not frost tolerant. If you live in a cold climate, it is best to plant marigolds in the spring or early summer and enjoy their bright colors until the first frost.
I am an accredited practicing dietitian, experienced gardener and a dedicated cook. I love writing and sharing my experience so you can learn from my successes and mistakes.