Last updated on October 22nd, 2023 at 09:19 pm
Growing nasturtium from seeds is fun, and the results are quite impressive. The bright blooms trail on sprawling vines, and bloom throughout the summer months, well into fall. Learn how to grow nasturtium from seed to bloom, and enjoy these delightful edible flowers in your garden.
Nasturtium is a useful plant with beautiful flowers that can easily be grown from seed.
The flowers of nasturtium are edible, and can be used as a colorful garnish for fresh salad or other culinary delights.
These old-fashioned favorites can be planted directly into the garden, grown along a trellis, or potted up to trail down the sides of a large container. They make an excellent addition to the flower and vegetable garden beds.
I grew several varieties in containers last summer, and enjoyed picking the tasty flowers and leaves throughout the growing season. The flowers are brilliant, and the leaves are perky, and the plant grows well as an ornamental in it’s own right.
The nasturtium plants grew well throughout the summer months, producing an abundance of edible blooms. It was a delight to grow them, and pluck them from the plant whenever a harvest was needed.
The leaves are also edible, and have a unique peppery taste.
If you leave some of the spent blooms in place on the plant, the plants will readily set seed, producing lots seeds for next year’s growing season.
Are Nasturtiums Easy To Grow?
Nasturtiums are very easy to grow, especially from seed. These are great plants for beginner gardeners, due to their ease of growing.
When I first planted nasturtiums I was pleased at just how easy it was to grow large and healthy nasturtium plants. The key is to not give them too much love, and to provide the correct nasturtium care.
The seeds germinated quickly, and the plants began to trail, even before they were removed from their cell trays.
The trailing nature of some plants is an important consideration for planting. Try not to let these seedlings linger too long in their growing cells, due to their tangling nature.
Nasturtium plants can also be grown from cuttings, and will easily root in water.
Last year I rooted a piece of stem that had broken from the main plant.
To do this, place a cut stem with leaf nodes into a glass of water. Within a week the stem will begin to produce small white roots, which will continue to grow in the water until planted into a container.
Although generally grown from seed, some nasturtium hybrids are sterile, and these cultivars must be propagated through cuttings.
Nasturtium is the common name for plants known as Tropaeolum.
These plants belong to the Genus Tropaeolum, which contains approximately 80 species of different annual and herbaceous perennial plants.
The plants are members of the Family Tropaeolaceae. The Genus Tropaeolum is the only genus within this family.
The common name of “nasturtium” is attributed to a similarity to another plant known as Nasturtium officinale, also known as watercress. Both of these plants produce an oil, which is similar in nature.
Tropaeolum majus is a species of nasturtium which is widely grown, and which has become naturalized in some parts of the United States, as well as in Europe, Asia, Africa, and Australia. This cultivar is also known as garden nasturtium, Indian cress, and monks cress.
The most common nasturtium varieties grown in gardens today are hybrids, produced by the cultivation of several species, including T. minus, T.majus, and T. peltophorum. There are many different varieties of nasturtium to choose from.
These nasturtium hybrids are grown as half hardy annuals, and are available in a variety of different colors and forms.
Some varieties of nasturtiums are vine-like with a trailing growth habit, while others have a bush-like form, with non-trailing bushy plants.
The ornamental features of the plant give it an attractive appearance, anywhere that it is planted.
Most often grown for the edible flowers, the plants can also be grown for their ornamental presentation and vine-like growth pattern. Nasturtium is also a wonderful garden plant, providing many benefits to the garden.
All parts of the nasturtium plants are edible, and both the flowers and leaves can be used for culinary purposes.
The large seeds of nasturtiums are nut-like in appearance. Each seed has three segments, which are more notable on smooth and immature seeds.
The seeds measure approximately 0.5 cm to 1.0 cm in length.
As the seeds form and mature on the plant, they turn from a light green to a tan color. When mature the seeds will fall from the plant.
After separation from the plant, the seeds will dry and wrinkle, and also further darken in color.
This a great time to collect the seeds, to save for the next growing season. Look around the base of the plant throughout the growing season, and collect any seeds that have fallen.
Nasturtium flowers grow at the tip of a long stalks which protrude from the axils of the plant’s leaves. Only one flower grows at the tip of each stalk.
Each flower blooms for about 5 to 7 days.
The flower colors commonly range along yellow and orange tones, however also include red flowers, creams and peach colored flowers as well. The flowers can be solid or striped, and will also often have a blotch at the very base of the petals.
Flowers may be single or double, and are intriguing and beautiful in appearance.
These showy flowers have five sepals at the rear of the flower, and five petals on the front of the flower.
The three lowest petals are clawed towards the back of the flower. These structures are held by the sepals.
The uppermost sepal has an elongated spur-like structure which protrudes from the back of the flower. This is the location of the nectary, which holds the nectar of the nasturtium flower.
Nasturtium flowers, as well as the leaves are edible, with a spicy and peppery flavor.
The flowers are bisexual, and most cultivars will easily form seeds throughout the growing season, if left in place.
Nasturtium Leaves And Stems
The alternate leaves of nasturtium are hairless and lobed.
Stems are succulent in nature, and are somewhat crisp and fluid filled. The stems are easily broken with handling.
Leaf stalks are long, and therefore tend to wrap around structures as they grow and trail.
Trailing varieties can be trained to grow up a trellis, or along fences for additional support. They can also be left to trail on the ground, and be grown as a ground cover.
If grown in containers, place in a high location, such as in a hanging basket, or in a pot on a stand, to allow the vine-like stems to fall and cascade gracefully as they grow.
Trailing varieties can develop long vines, which reach up to 5 feet in length.
Growing Nasturtium From Seeds
Growing nasturtium from seeds begins with the selection of the seeds themselves. Consider the color and form of the flowers that you would like to grow in your garden or containers, as well as your sowing plan.
Nasturtiums are half hardy annuals, and therefore they will not tolerate exposure to cold spring frosts.
As a result, the plants should be either directly sown outside in late spring, after the risk of frost has passed, or alternatively, started early from seeds indoors and planted outside when the weather warms up.
Growing nasturtium from seeds is relatively easy, just make sure not to start the seeds too early for your growing location.
How Long Does It Take Nasturtium Seeds To Germinate?
Nasutium seeds will germinate generally within 7 to 14 days in ideal growing conditions.
The seeds require darkness for gemination, so make sure that they have been covered with growing medium or vermiculite when planting.
Some gardeners soak their nasturtium seeds for up to 8 hours before planting to soften the seed coat, however this is not necessary for successful germination of the seeds.
- If you plan to direct seed into the garden, do this at a time when the danger of frost has passed. Know your last spring frost date for your usda plant hardiness zone, and plant your seeds one week past the specified last frost of the season.
- Direct sow seeds into a weed free prepared garden bed, planting seeds 1/4 to 1/2 inch deep. Sow 2 to 3 seeds per hole to ensure planting success.
- Thin to the strongest plant once the seedlings are growing.
- Space smaller varieties 6 to 12 inches apart, and larger varieties 24 to 38 inches apart. Follow the directions on your seed packets to determine individual plant spacing needs.
- The seeds will have faster germination rates when the garden soil is warm, between 55° F to 65° F (12°C to 18°C),and therefore may be slightly delayed if the soil remains on the cool side.
Planting your nasturtium seeds indoors will give you a head start on the growing season, and the plants an earlier start, however be sure not to plant them too early.
Early planting will result in good sized seedlings which may tangle together in cell trays before they are ready to be planted outside.
If the seedlings begin to exhibit this risk before they are ready to be transplanted outside, pot them up into separate containers to give them the space that they require for growth.
To Plant Indoors:
- Fill a seed starting cell tray ( such as a 72 cell tray) with a sterile potting mix. You can also use multiple small pots.
- A biodegradable pot is also a good choice for planting.
- Plant 1 to 2 nasturtium seeds per cell, approximately 1/4 to 1/2 inch deep.
- Cover with potting mix or vermiculite.
- Bottom water the tray.
- Remember to keep the medium moist while the seeds are germinating, and do not allow the soil to dry out during this time.
- Place the cell tray on a heat mat to provide bottom heat.
- When 60% of the seeds have germinated, remove from the heat mat, and place under a grow light. Provide at least 14 to 16 hours of light per day.
- The seedlings should remain under the grow lights until hardened off and transplanted outside. The hardening off process will help to acclimatize the tender nasturtium seedlings to the outdoor environment.
When To Transplant Outdoors
Transplant out into the garden, or into containers, when the weather warms up.
It’s important to transplant the nasturtium seedlings outdoors after your last frost date, when the danger of frost has passed.
Half hardy annual plants do not tolerate frost, and will likely perish in colder climates if planted out too early.
After the seedlings are transplanted, water in well.
Keep the planting area watered until the plants recover from the planting, to help prevent transplant shock.
Growing Nasturtium In Pots
- If you plan to grow nasturtiums in pots, you can either directly sow the seeds into the pot in warmer weather, or transplant indoor grown seedlings into the pot when the timing is right.
- Choose a container with good drainage and freely flowing drainage holes.
- Select a potting mix without any additional fertilizer added to the mix.
- Either way you will have fabulous container grown nasturtiums, ready for the picking.
- Make sure to transplant the seedings into the pot before they have tangled together in the cell trays, because this will cause breakage and stress for the plants.
- Space plants at least 6 inches apart.
- Water in well after planting, and water regularly until the plants are established in their growing containers.
- Once established, water the containers as needed, and it’s okay to allow them to go dry for short periods in between waterings.
- If you water them more frequently, the plants will also respond well to the additional waterings.
- Nasturtiums grow very well in sandy soil, poor to average well-drained soil, and dry conditions.
- These summer annuals are great to grow in a difficult planting site, with less than ideal soil, as long as there is good drainage.
- When grown in highly fertile soils, the plant will produce lots of foliage, however flower production will be reduced.
- Make sure not to fertilize for best flower production.
- Nasturtium grows well in full sun to partial shade.
- Grow nasturtium in a full sun location for best flowering and growth results.
- In hot climates plant in an area where the plants will receive afternoon shade for best results.
- Nasturtiums are drought tolerant, however will respond to watering, especially when grown in containers.
- Water nasturtiums during dry periods, or as necessary. The plants will benefit from watering.
- Aphids are a pest for nasturtium plants.
- In fact, nasturtiums are sometimes considered to be a good trap crop in the garden, due to their nature of luring aphids away from other garden plants.
- To remove the aphids from the nasturtium plants, treat with a burst of water from a hose, to forcefully spray the small bugs from the plant.
- Nasturtium is also considered to be a great companion plant for Brassicas, radishes, tomatoes, cucumbers and melons, deterring multiple pests such as cucumber beetles, white flies, and squash beetles.
Frequently Asked Questions
Why Do My Nasturtiums Have No Flowers?
The most likely cause of lack of flowering on nasturtium plants is that the growing medium or soil is too fertile in nature.
When planted in poor soil, rather than in fertile soil, nasturtiums will have better flowering results.
When Do Nasturtiums Flower?
Nasturtiums flower fairly quickly in ideal growing conditions. They generally begin to produce the first flowers in early summer, within 4 to 6 weeks of planting.
Once blooming, expect the plant to continue to bloom throughout the growing season, right through until the first frost in fall.
Remember not to be too generous with the growing medium, as you will have better flowering with less fertile soil.
Do Nasturtiums Come Back Every Year?
Within the nasturtium genus there are many different species, some of which are perennial, and will return to the garden every year.
The most common nasturtium plants grown however, are half hardy annual hybrids, and these plants will not return to the garden every year. In warmer growing zones not exposed to frost, the plants may self seed with volunteer plants the following season.
In colder climates the seeds will need to be collected, to be planted out again the next year.
Fortunately the plants will produce lots of seeds during the growing season.
If you collect some of these seeds every year, you can perpetuate the plants in the garden, year after year, by planting them every season.
Do Nasturtiums Attract Bees?
Nasturtium flowers, with their vibrant colors, attract bees and other beneficial insects to the garden space.
The lovely flowers are a great source of nectar not only for bees, but also for butterflies, birds, and other beneficial insects.
The long nectary will allow hummingbirds to access nectar deep within the structure. When the nectary is full, smaller insects and bees will also be able to access the nectar.
Nasturtium nectar is sweet, and a valuable food source for these beneficial insects and birds.
If you are planning some grow edible flowers, consider growing nasturtium from seeds, to plant this beautiful addition in your flower or vegetable garden this season.
These annual plants are easy to grow, require little care, and will reward you with prolific blooms all season long. They are a great choice for children’s gardens, due to their pretty flowers and low maintenance care.
These fast growing plants have culinary use, are beneficial to wildlife, make good companion plants, and also help to beautify the garden beds.
Grow these ornamental flowers in containers or in window boxes for a bright pop of color. The plants also make a great groundcover where needed.
Don’t forget to save some seeds at the end of the season. This will help to perpetuate these fabulous annual flowers in your garden, year after year.
Have you ever tried growing nasturtium from seeds? Be sure to leave a comment below to share your experience!