Grow Your Own Nasturtium Flowers
Nasturtiums are some of my favorite flowers to grow in the garden. They produce these cute little leaves that look like lily pads, not to mention gorgeous hibiscus-like flowers that are much easier (and faster!) to grow than their lookalikes.
Nasturtiums are originally from South America, and they're pretty much the only plant in the Tropaeolaceae family you might grow in your vegetable garden. That means nasturtiums are in a league of their own!
I love growing nasturtiums because, one, they're beautiful; two, they protect your lettuce plants from pests; three, the entire plant is edible; and four, they trail, and if you know me, you know I love growing things over the side of raised beds.
Here's how to plant and grow nasturtiums, plus different ways to enjoy every single part of this plant in your garden and your kitchen.
3 Reasons to Grow Nasturtium Flowers
One: Every Part of the Plant Is Edible
The leaves, flowers, and even immature seedpods of nasturtiums are edible. I find nasturtiums delicious, but the peppery bite might be a bit much for some people. Nasturtiums actually got their name from the Latin phrase "nose twister" thanks to this spicy kick, which botanists compared to watercress and mustard greens.
If you're not into growing and eating nasturtiums as a salad green, the flowers still make a pretty little garnish.
Two: Nasturtiums Help You Control Pests Organically
The compound that makes nasturtiums so spicy actually repels certain pests like whiteflies from your garden. Other pests are not repelled—they're drawn in. Why is that a good thing? Because pests like aphids and flea beetles will hang out on your nasturtium plants instead of your lettuce and cabbage plants.
Nasturtiums are what we call a trap crop, or sacrificial plant. (That makes it sound like your plants will die from these pest attacks; they'll likely be totally fine.)
Three: Nasturtiums Attract Pollinators
Pests aren't the only thing that these flowers attract. Beneficial insects, like hoverflies, and pollinators, particularly bees and hummingbirds, go wild for these blooms. (Bumble bees and hummingbirds especially love the deep red flowers.)
2 Main Types of Nasturtium Plant
Based on where you'd like to grow your nasturtiums, you can choose between a trailing type or a bush type.
Trailing Nasturtiums
This type forms long vines that will climb up to 3 feet toward sunlight. Grow this type up a trellis or fence, in a hanging basket or window box, or even as ground cover. I actually love to grow trailing nasturtiums on the very edge of raised beds so that they can cascade over the sides. That way, you still have lots of space around these flowers to grow other plants.
Trailing Nasturtiums
This type grows more compact, reaching just 12 inches tall. Grow bush nasturtiums in containers or smaller garden beds.
As for color, you can find both jewel-toned and pastel shades of red, peach, and cream, on top of the original nasturtium colors of yellow and orange. You can even find variegated leaves. Some of my favorite nasturtium varieties to grow are Yeti with its ivory-colored blooms, Tip Top Alaska Salmon Nasturtium, and Peach Melba.
Where to Grow Nasturtiums
Keep the growth habit of the nasturtium type in mind when you're picking a spot. If you've got seeds for a trailing type, make sure you plant it right next to a trellis for the vines to climb or on the edge of a raised bed or container so that the plant can spill over the side. (And if you have a long growing season, prepare for those vines to take over your garden paths!)
I like to plant nasturtium seeds all along the edge of raised beds that are growing leafy greens. Just don't plant trailing nasturtium in the center of a raised bed because it'll take over.
If you've got trellis space to spare, try growing climbing nasturtiums up a trellis. This is one of the few plants you can grow for its leaves that will fill a trellis beautifully. Can you imagine standing under a lush trellis and picking leaves for your salad bowl? You'd feel like a garden queen.
To take full advantage of nasturtium's role as a trap crop, plant it around the border of garden beds that'll grow plants prone to aphid and flea beetle attacks. Think lettuce, kale, beans, eggplant, cabbage, broccoli, and cucumber,
Nasturtium Growing Conditions
Sun
Nasturtium plants will grow in partial shade, but you won't really get many flowers. That's fine if you're just growing this plant for its edible leaves. If you want the blooms as well, pick a spot that gets at least 6 hours of sunlight.
Soil
Nasturtiums can thrive in not-great soil. My plants love the sandy loam soil in my raised beds and don't really require any extra fertilizer beyond some seasonal compost. Keep in mind that if you're growing nasturtiums around a bunch of salad plants that you're feeding with nitrogen, you'll encourage your nasturtiums to produce more leaves, not flowers.
Season
Nasturtiums generally prefer warm but not hot weather. Your plants will struggle once the temps reach 90°F.
I learned the hard way that nasturtiums are not at all frost tolerant. That's why most seed packets will say to wait 1 to 2 weeks after your average last frost in the spring to sow seeds.
Nasturtiums are typically grown as annual plants. If you live in a frost-free area, these can actually be perennial plants, meaning they can keep going on and on. Back when I lived in Houston, we had a particularly mild winter, so I was able to grow my plants all winter long and through the next spring.
If you're past your last frost date and you've got cool to warm temps for the next couple of months, that's a great time to grow nasturtiums in your vegetable garden.
How to Grow Nasturtiums from Seed
Nasturtiums are super fun to grow from seed. These plants don't transplant well, so I don't recommend starting them indoors or buying little seedlings from a nursery. (If you do start them indoors, use biodegradable pots or root trainers to minimize disturbances to the fragile roots. Start them 4 to 6 weeks before your average last frost date.)
Nasturtium seeds are nice and large. They look like little brains. Large seeds are so much easier to plant and handle in the garden than smaller ones. That being said, these seeds do benefit from an extra planting step. Let's look at the the steps to sow nasturtium seeds.
Step One: Scarify Seeds
This step is optional. You can just plant your seeds directly in the ground if you prefer. I've done that before, and it works out just fine. However, scarifying your seeds will speed up the germination process and increase your success rates.
Why do you need to prep the seeds for planting? Well, because nasturtiums aren't frost-tolerant plants, they've developed a pretty ingenious way to protect their seeds from sprouting when it's not yet time for them to grow. They have a thick seed coat, and that means they have to sit in warm soil and allow water to wear down that coat for a long time before they're ready to grow. We can speed this process up through scarification. What would typically take 4 or 5 days, we can accomplish in 12 hours.
To scarify nasturtium seeds, use a little nail file or piece of sandpaper to carefully wear the outside coating of the seed down until the lighter inner layer is revealed. You only have to expose a little bit of the seed, not the entire thing.
Step Two: Soak Seeds
Place your seeds in lukewarm water to soak for 8 to 10 hours, or overnight. The seeds will swell up and be ready for immediate planting.
Step Three: Sow Seeds
Use a dibber to make holes just 1/2 inch deep and spaced 10 to 12 inches apart. Place one nasturtium seed per planting hole and then cover them up with fresh compost. That's it.
Keep the soil moist while you're waiting on germination. You should see little shoots appear in 7 to 10 days.
Nasturtium Care
Nasturtiums are pretty easy-going plants. I don't do anything special to them in my garden.
These plants are somewhat drought-tolerant once they're established. I water them whenever the rest of my garden needs water. Once the weather warms up in the summer, pay more attention to the moisture level in the soil so that your plants don't get all stressed out by the heat. Otherwise, they'll stop blooming (and the leaves become a bit too spicy).
Here's where I'd typically advise you to water the soil around the plant, not the leaves, but nasturtiums have a nifty little adaptation to prevent the spread of fungal disease and bacteria on their leaves in warm climates. Those round leaves are actually water-repellent, which is really cool.
Other than water, pinch off any faded flowers to encourage your plants to keep producing new blooms. If your plants start crowding other plants, prune some stems back at the base.
Finally, if your plants are taking their role as a trap crop seriously and now covered in pests, you can either leave the pests be or handle them. Remove larger pests like cabbageworms by hand, prune damaged leaves, and give your plants a good spray of water to scatter aphids. (They're bad at regrouping.) Avoid using any kind of pesticides, even organic ones. Your nasturtiums can handle some pest pressure just fine.
How to Harvest Nasturtiums
Harvesting the Leaves
You can harvest the leaves as soon as they're large enough to toss in your salad bowl. Just use a clean pair of scissors or pruners to cut individual leaves. Avoid harvesting more than a third of the plant's leaves at one time.
Harvesting the Flowers
The best time to harvest flowers is right after they've opened up. You'll get the best flavor if you harvest in the morning. Use a clean pair of pruners or scissors to cut just below the flower.
Bring your flowers inside to wash carefully and dry. Leave the plant to form more delicious flowers for you to eat later.
Harvesting the Seeds
Nasturtiums reseed themselves very easily. Almost as soon as the flowers start to fade, they're producing those really large brains (seeds). And if you're not paying attention, those things will drop all over your garden, and you'll get more nasturtium plants the following year. (It's like these plants have minds of their own!)
To harvest the seeds, just check in the center of a fading flower. Seeds will usually be in groups of three. If you want to eat the seeds, harvest them while they're green and still immature by tugging them off the plant.
If you plan to save the seeds for next year, wait until they're tan and hard. They'll be much easier to pick at this stage. Check around your plants for any seeds that have dropped from the plant, as well. Let seeds dry out a bit more somewhere dry and dark before you store them in an envelope for next year.
How to Enjoy Nasturtiums
Enjoying the Leaves
I love to throw nasturtium leaves in my salad bowl. As I said, I treat this plant like any typical salad green. You can also wilt or sauté the greens just like you would spinach or arugula. I typically prefer the younger, more tender greens for eating fresh. Older leaves can be a bit bitter.
Enjoying the Flowers
Like the greens, you can toss these gorgeous flowers onto your salad, as well. Now you've got an extremely gourmet garden-to-table meal. The flowers are a little sweeter and less peppery than the leaves, so you may find them more enjoyable. If not, use them as garnishes on desserts, cheese boards, or my fav, butter boards. If you really want to impress your friends the next time you host, freeze some edible flowers in ice cubes.
You can also make your own salad dressing by infusing nasturtium flowers in vinegar. Just pour white wine vinegar over the blooms and leave the jar in a dry, dark spot for a couple of weeks.
Enjoying the Seedpods
Here's something really neat: you can pickle or ferment your nasturtium seeds and use them like capers. Course, I'm not gourmet enough to have tried this yet, but it's still really cool.
Nasturtium Benefits
The compound that gives nasturtiums their pungent peppery flavor, glucosinolate, also makes these plants naturally antibacterial. Early studies have shown that taking nasturtiums and horseradish together can effectively treat UTIs. I'm not saying you should stop taking prescribed antibiotics (please don't!), but it's pretty cool to learn about the incredible power of plants. The next time you eat some nasturtiums, you can at least feel good that you're fighting germs in your body.
The leaves and flowers also contain lutein and vitamin C, so these plants are wonderful to fill up on during cold season. You'll also get various more antioxidants depending on the flower color.
Now, if you're excited about these nasturtium benefits but it's not the right time to grow them in your garden, don't worry! You can reap all these benefits by enjoying nasturtiums as microgreens.
Time to Grow Some Nasturtiums!
I hope you're excited to get that fresh, peppery taste in just a couple of weeks. If you live in North America, the fall is a great time to plant nasturtiums. Grab your seeds for your salad garden and grow some nasturtiums this season.
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