Are Nasturtiums Frost Hardy? – Facts, Guides, And More You Need To Know

What are nasturtiums?

Nasturtiums or Tropaeolum majus are flowers, but they are also vegetables, and we can eat them. We can find these flower vegetables in bread rolls, salads, and quiches. We can even stuff the leaves and make them become delicious meals.

Summer and autumn are two seasons in which nasturtiums can thrive the most.

More specifically, we can plant them around March until May each year. Not to forget, they can sustain frostings to some extent.

However, we may want to ask ourselves, “Are nasturtiums frost hardy?”

Hence, we present this article to let you know how much nasturtium flowers can sustain frosts. We will also give you the facts and guides that have that question as to the center.

Are nasturtiums frost hardy?

No. Even though nasturtiums can handle some frostings, they are not hardy because they can only sustain smaller amounts of frosts. Nasturtiums can sustain frosts for up to 30-40 degrees Fahrenheit (or -1.11 to 4.44 degrees Celcius). 

Nasturtiums are also never hardy regardless of the seasons or whether they are annuals or perennials.

The perennials should even be kept frost-free until we can store them somewhere else in the winter. On the other hand, the winter periods are when you shouldn’t expose the nasturtiums.

Several nasturtium types are grown as perennials in USDA growth zones 9 through 11. However, in most North American climes, this plant is considered an annual, with its life cycle completed in only one growing season.

Cold and wintery weather is not ideal for nurturing nasturtiums’ growth. The excessive coldness will eventually kill nasturtiums.

How do excessive frosts kill nasturtiums?

We’ve now known the answer to the “Are nasturtiums frost hardy?” question, which is no. So, the next thing we wish to uncover is how frosts can kill nasturtiums, even though these flowers can sprout back after some smaller bits of frost or freeze.

Excessive frosts don’t directly kill nasturtiums.

The colder the temperature near the nasturtiums, the more the nasturtiums shed their seeds. The shedding is the beginning of their death. The first frosts will kill most of the nasturtiums, even when there are other nasturtiums around the flowers.

The first frosts do not only kill nasturtiums and the non-frost hardy plants nearby. They will also make nasturtiums easier to weed out.

How long should you wait for nasturtiums to grow?

Nasturtiums are preferable to grow indoors than outdoors, even though they are not frost-hardy or can only resist cold temperatures.

Indoor places often become the shelters for nasturtiums after the most recent spring frosts.

On a typical basis, you should wait for the nasturtium flowers to grow for around 5-6 weeks after exposure to frosts and freezes.

Such timings are crucial for the flowers to adjust the temperatures to neutralize the damaging effects of excessive colds.

Be sure to provide adequate sunlight to the nasturtium flowers.

The light sources can be from outside the windows or from study lamps. Once the frost dangers become more controllable, you can plant the nasturtiums outdoors and take care of them once every 24 hours.

How can you germinate nasturtium seeds outdoors?

Many people say nasturtiums thrive in sunny temperatures. Hence, these people choose to germinate and plant their nasturtiums outside a closed space. Nonetheless, we can’t germinate the seeds when the dangers from the frosts have not completely gone.

You should first prepare to germinate nasturtium seeds in outdoor places to ensure the soil has warmed to 65 degrees Fahrenheit (or 18.33 degrees Celcius). In addition, you can soak the seeds in warm water for 24 hours. 

When you finally plant the flowers’ seeds, choose peat pots that you can transplant directly to the soil. It is because nasturtiums detest having their roots disturbed in any manner. After proper germination, the seeds will germinate in 10-14 days.

Alternatively, you can also jump-start your nasturtiums’ growth by germinating the seeds inside a dried paper towel. In doing so, you can speed up the germinating processes by 7-10 days.

What are the best ways to plant nasturtium flowers?

Nasturtiums are some flower types that are convenient to plant, care for, and maintain. Nonetheless, there are specific ways to sustain their lives and fertility.

Full sun is the best environment to plant nasturtium flowers. You can even give them partial shades if you plant these flower vegetables indoors.

Getting rid of aphids and garden pests is among nasturtiums’ best abilities. Hence, we should consider nearby plants when we plant nasturtiums. For example, these flower types are compatible with beans, broccoli, melons, and radishes.

It’s also important to mix and match vegetables, flowers, and other plants.

In other words, never plant two kinds of a plant if the two don’t get along with each other. In doing so, we can help them attract butterflies, hummingbirds, and other beneficial insects.

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