These gorgeous, climbing blooms often appear in red, orange, and yellow – this old-fashioned flowering plant is coming back in style.
You should plant one nasturtium seed per square foot in your garden, whether that’s an already established garden full of vegetables and flowers.
Or if this is the first plant you’ve ever grown in your life, nasturtiums are a cheerful, easy-to-care-for addition to your home garden.
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What Is a Nasturtium?
The common name for this sprightly, colorful flower is actually from the watercress plant. Nasturtiums are from the Tropaeolum genus, which includes over 80 species of these flowers.
Watercress is an Asian vegetable known as Nasturtium offininale is a different plant.
Confusingly, the adorable nasturtium flower has that common name because it produces an oil similar to that of the watercress plant.
Although watercress is more known as an edible plant, especially in East and Southeast Asian dishes, nasturtium flowers have been eaten in dishes like salads by people in Mexico and Peru for centuries.
It was spread to the Old World by the Spanish, and now it thrives all over the world.
You must grow this annual plant from seeds. It’s annual because when the weather becomes hotter, around 85 degrees Fahrenheit, the plant can’t take it anymore.
You can grow nasturtiums anywhere but be advised that if you get frosts in the winter, plant them afterward so you can enjoy blooms in the spring.
If you live somewhere tropical like Florida, you can plant your nasturtium seeds anytime, even in the fall, so that you can see their colors pop in winter.
Because nasturtiums are annual, once you enjoy their blooms, after a season, they’ll begin to disappear, and you will have to replant them. But don’t worry, the process is a simple one.
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Growing Nasturtiums Step-by-Step
- Purchase nasturtium seeds. You can choose from many color variations, including red, yellow, maroon, orange, pink, and sometimes purple. Some seed packs have a variety of colors, so you can be surprised when your blooms begin appearing.
- Some gardeners choose to soak their seeds first. This breaks down the seeds’ protective coating. If you choose to do this, only soak them for a few hours in room-temperature water.
- Although you can start by growing your nasturtium seeds indoors and transplanting them outdoors, this is not recommended. It is simply adding steps to a simple process. Next, plant your nasturtium seeds about one inch into the ground with one square foot of area per seed.
- A helpful tip is to label your nasturtiums—before they begin flowering, you could mistake them for weeds! After about a week or two, you should see nasturtium sprouting up in your outdoor garden.
Surprisingly to some, nasturtiums do best in what we call “poor soil.” This is soil that is rocky or sandy and doesn’t have an overabundance of nutrients.
Nasturtiums are native to Central and South America, but in places where it’s difficult to grow, at high altitudes and in unfertile soil.
This is why they do well in these types of soils, and why you should not fertilize them. If you fertilize nasturtiums, they will explode with leaves but hardly any flowers.
Make sure the soil you use is well-draining. You can use a mixture of peat moss and loam along with sand, just nothing that stays wet.
You can water your nasturtiums about an inch per week, which is low maintenance considering that many other plants require more water.
You should water them twice a week if it’s hot outside, as their water supply will evaporate more quickly.
The best time to water nasturtiums, as with many flowers, is in the early morning or early evening when the sun is not directly overhead.
This will prevent the leaves from scorching and give the water more opportunity to penetrate the ground.
These hardy little plants love full sun, which means six to eight hours of sunlight per day.
If you plant them somewhere that has significant amounts of shade throughout the day, they will still grow, but you will get many more flowers if you plant them in full sunlight.
If you see wilted or dried-out flowers, prune them off. This stimulates the growth of new, healthy flowers, and it keeps the plant blooming longer.
You can place mulch atop the soil you’re growing nasturtiums in.
Don’t lay it on too thick, but you can intersperse mulch throughout your garden so that you will not have to water the flowers too often.
Nasturtiums are somewhat drought resistant, so it’s better to under-water them than to overwater them. Just ensure that the top inch of soil stays moist most of the time.
If you pinch off or prune spent vines and flowers, it will keep your nasturtiums looking healthy and full.
You can let your plants grow wildly if you prefer, but a strategic pinch here and there will add to the overall health and aesthetic of these plants.
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Three Main Types of Nasturtiums
Here are the three main types of nasturtiums you may consider planting.
This is often the type of nasturtium that comes up when you search for images of the flowers.
They can climb on vines up to twelve feet tall. If you choose to plant the climbing variety of nasturtium, make sure that you place a trellis for them to climb near the garden.
You can also plant them near a wall, but you need to do this where they can still get full sunlight to get as many nasturtium blooms as you possibly can.
However, you don’t need to allow these vines to climb. They can instead grow across the ground like a protective, pest-baiting carpet to protect your other plants.
Unlike their climbing brethren, mounding nasturtiums grow together in a centralized bush. The bush is about a foot wide and can be fifteen inches tall.
These lovely little bunches of nasturtiums do not wander, so you can plant them in corners of your garden or as borders.
You can even grow them indoors in a pot if you would like, as long as you ensure to provide them with a well-draining pot, full sunlight, and consistent temperatures.
This type of nasturtium is a mixture of climbing and mounding nasturtiums because they do grow vines, but they’re confined to about two or three feet long.
These are perfect plants for growing in hanging baskets as their blooms will trail over the sides of the basket and hang down nicely.
Uses of Nasturtium
Here are some common uses of nasturtium.
Nasturtiums are wonderful plants on their own, but many gardeners use them as “trap crops.”
A trap crop is just what it sounds like—biological pests go after the nasturtiums instead of the companion veggies they’re planted around.
There is virtually no vegetable you cannot grow in the same garden as your nasturtiums, and these flowers can form a shield against pests for your vegetables.
Ironically, their scientific name, Tropaeolum (from the Latin for “trophy pole”) majus, was given to them by Carl Linnaeus, the father of binomial nomenclature.
Due to the fact they resemble Roman shields (round leaves) and victory flags (red flowers). They can be your vegetable shields.
Because of the nasturtium’s long indigenous history, it has been used medicinally for different ailments such as urinary tract infections and respiratory infections.
These are traditional uses still practiced today, especially as holistic medicine used by naturopaths, but there isn’t scientific evidence to back up any efficacy of nasturtium’s treatment for these infections.
Nasturtium is also used as an antifungal and antiseptic—one can grind up the leaves and use them as a paste or crush the seeds and do the same and apply the paste to wounds.
Again, more evidence needs to be collected to verify whether these treatments provide actual relief. It is said that eating nasturtium can fight bronchitis.
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Not only do nasturtium blooms add beauty to salads and dishes, but they can also provide a crisp and refreshing taste. You can add flowers and leaves to your soups and salads.
You can also garnish sweet or sour cocktails with a flower or two, and you can collect seeds from your current nasturtiums to place in salads and other dishes and to dry out and plant next year.
To add a peppery bite to your homemade pesto sauce, you can grind up nasturtium’s round leaves into it.
Nasturtiums are helpful to your garden and they come in handy on your table, and they may even carry some yet-to-be-solidified medical properties, but you can simply plant them for their aesthetic value.
There are over 80 species of nasturtiums, many of which have been created by botanists and gardeners for their color varieties.
These color variations are called cultivars, as they are made especially for their colors and ease of cultivation.
Some of the most popular of these beautifully colored cultivars are the Canary creeper, the wreath nasturtium, the flame flower, and the blue nasturtium.
Common Nasturtium Pests
It may be surprising for new gardeners to learn that the easygoing nasturtium attracts an array of pests, but this is strangely one of the main reasons seasoned gardeners plant this plucky little annual.
Because so many insect pests go after nasturtiums first, especially if they’re planted in a perimeter around your vegetables, your harder-to-grow and protect vegetables have a defense against these fiendish insects.
Nasturtiums themselves may not be bothered by whiteflies directly because they produce a chemical that deters whiteflies attracted to your other plants.
Whiteflies are especially attracted to plants that produce any sort of sap on their stems.
Aphids and Cabbage Moths
Aphids are notorious for eating the leaves of their vegetables and snacking on sap.
Luckily, if you have plenty of nasturtium around, they will munch on your nasturtium flowers rather than your tomatoes, squash, or cucumbers.
Cabbage moths, aptly named for their taste for broccoli, cabbage, and kale, will also choose nasturtiums as their appetizers.
So you can first defend your veggies with nasturtiums and then pesticides, if necessary.
These leaf-chomping pests are tantalized by the abundance of leaves nasturtium plants provide.
But luckily, that gives you more time to plan an assault and defense for your other garden plants, like corn and alfalfa. Although grasshoppers prefer grains, they will go after almost anything.
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Like aphids, spider mites are attracted to sappy plants like poinsettias, ficus plants, monsters, and other indoor potted plants.
However, they are also attracted to nasturtiums because those can produce enough sap to entice spider mites.
You can use neem oil to battle these sap-suckers and keep the rest of your garden safe.
Although your nasturtiums may act as a shield and first line of defense against insect pests in your garden, that doesn’t mean you want to lose them altogether.
You can spray a neem oil solution on the soil around your nasturtiums.
If you don’t plan on eating your nasturtiums, you can use them to attract the pests and then come in with chemical insecticide so that you no longer have a pest problem.
Nasturtium Fun Facts
- Nasturtium is the Latin name of the watercress plant, and it means “nose-twister.”
- In the Victorian language of flowers, nasturtiums symbolized a secret or forbidden love, or love that you were willing to fight for despite obstacles.
- Snails and slugs are not typically attracted to nasturtiums, unlike the vegetables these flowers tend to be planted to protect.
- Unripe seed pods of nasturtiums are sometimes used as substitutes for capers because of the flavor resemblance.
- Unlike most nasturtiums, which are annuals, there is a perennial type of nasturtium that grows in Chile at an altitude of 10,000 feet in the Andes (Tropaeolum polyphyllum).
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No matter if you’re an experienced farmer who’s been planting and growing nasturtium for years as a pest deterrent or if you just like the appearance of the flowers and you want to try your hand at growing these hardy little plants, they can be a joy to grow and cultivate.
I’m Elsa, and I love gardening. I started GardeningElsa.com as a resource for other gardeners, and I offer expert advice on gardening topics such as plants, flowers, herbs, and vegetable gardening. On my website, I share my latest tips and tricks for creating beautiful gardens. When I’m not working on my website, you can find me in my own garden, tending to my plants and flowers. Read more about me.