Growing Nasturtiums 

Nasturtiums are a favorite flower to grow amongst home gardeners and market farmers alike. Easy to grow from seed and adaptable to almost any growing zone, nasturtiums can be a beginning gardener's best friend. Nasturtiums are a tender perennial in zones 9-11 but can be grown successfully as an annual just about anywhere. This quality makes them an excellent addition to children's gardens as well. 

If you could only pick one flower to grow in the garden, this should be it. Nasturtiums come in a wide variety of colors and growth habits, from bushy little dwarf plants to 15-foot long vining types. They are fantastic companion plants for attracting beneficial insects to the garden and work well as a trap crop for many kinds of aphids. 

Last but certainly not least, all parts of the common garden nasturtium are edible; the leaves and flowers are great in salads. The stems and unripe seed pods can also be safely consumed. They lend a deliciously peppery, slightly sweet component to just about any dish.

What kind of nasturtiums should I plant?

The most common garden varieties are Tropaeolum majus, Tropaeolum lobbianum, Tropaeolum minus, and Tropaeolum nanum. All originate from Central and South America. Not to be confused with Nasturtium officinale, commonly known as watercress. Garden nasturtiums are sometimes called Indian Cress because they were first brought to Europe from Central and South America when it was erroneously referred to as the indies. 

Tropaeolum majus 

Includes large mounding bush plant types. These are great for growing outdoors in the vegetable garden and purely decorative flower gardens. 

Tropaeolum lobbianum 

The incredibly prolific vining types can be used to cover fences, rock walls, and areas with poor soil all summer long. 

Tropaeolum minus, nanum 

These names are used for most dwarf types of nasturtium plants. These look great in hanging baskets and smaller pots. They can also be grown indoors on a sunny window sill. 

Rare Nasturtium Types.

There are other types of members of the Tropaeolaceae family beyond the traditional garden types listed above that are grown for various reasons. Some for their hardiness at high altitudes. Different varieties are grown for their edible tuberous roots known as mashua in the Andes mountains. Others like flame flowers are grown in colder wet climates where they thrive twining through hedges.

Top 10 nasturtium flowers to grow in your garden. 

Many seed suppliers carry several different nasturtium varieties. Here is a list of the top 10 to look for, whether you are shopping online or at your favorite local nursery.  

Tall Trailing Mix Nasturtium -

These beauties can grow over 10' in a season and come in a cheerful mix of reds, yellows, and oranges. They can be trained to climb fences, trellises, arbors, and along walls.  

Empress of India -

The gorgeous deep orangish-red blossoms of this variety are perfectly offset by their unique foliage, a deep bluish-green and darker than most types. It also makes an excellent choice for nasturtium microgreens.

Alaska Red Shades -

The Alaska series of nasturtiums offers truly variegated leaves mixed with cream and pale green mottled within the same leaf. Seeds will often produce flowers in shades of red from pale orangey-red to nearly black, depending on your growing conditions. 

Climbing Phoenix -

The split petals of this vining variety have jagged edges that make them resemble climbing bursts of fiery feathers. Typically sold as a mix, you will see bright and pastel shades of yellow, orange, peach, crimson, and near purple.

Orchid Cream -

Pale cream petals, each intricately splashed with deep red strokes emanating from the flower's throat. These compact mounding plants look great in pots or planted along the edges of your garden beds. 

Jewel Mix -

These large mounding plants are great starter packs for the new nasturtium grower or those looking for various colors ranging from yellow, orange, and red to flowers whose petals show a mix of all three. 

Dwarf Jewel Mix -

Very similar to the traditional jewel mix but with a compact mounding growth pattern. This variety looks great in hanging baskets on the porch or grown indoors on a sunny window sill.

Peach Melba -

The lightly lobed blue-grey leaves of this variety contrast beautifully with the creamy yellow blossoms. The center of three petals is marked with a starburst of pale orange, while the top two show streaks of red radiating upward. 

Black Velvet -

One of the most striking nasturtiums available, the flowers are such a deep dark red that they appear black. 

Whirlybird Series -

These have fuller double petaled flowers giving them a fuller look and adding a unique shape to your nasturtium patch with their mounding growth habit. They are often sold in a mix of cherry pink, pale yellow, peach, tangerine, mahogany, scarlet and deep gold. You can sometimes find this type in single-color packs.

How to grow nasturtiums.

Nasturtium seeds are pretty large and easy to plant. Growing nasturtiums is extremely gratifying since they quickly grow and flower when planted directly in the garden. Nasturtiums are not frost tolerant, so they are best planted out a week or two after your last expected frost date.

To plant your nasturtium seeds:

• Poke holes 1 inch deep about 2-3 inches apart in the area you wish to plant.
• Sow one seed in each hole and cover lightly with soil.
• Water in well and keep the soil moist until germination. Seeds will typically sprout in around 7 days.
• Thin plants to one every 6-12 inches
• Once plants are established, water deeply once a week.

Starting nasturtium seeds indoors

Nasturtium plants do not like to be transplanted since root disturbance will stunt their growth. If you have a short growing season and would like to get a head start on growing, we recommend using one of our 32-cell seed starting trays with insert pots to start your seeds. These larger individual pots allow you to easily transplant your babies with minimal root disturbance. For more on this, check out our article on How to Transplant Seedlings over on our Seed Starting blog.

To plant nasturtiums indoors:

• Start 3-4 weeks before your last frost date.
• Fill your seed starting pots with soil.
• Poke a one-inch deep hole in each pot and sow a seed in it.
• Cover seeds with soil and water well.
• Keep moist until germination occurs.
• Plant out 6-12 inches apart in well-draining soil when all danger of frost has passed and seedlings have at least two sets of true leaves.
• Water well once a week as overwatering will cause more foliage than flowers to grow.

Saving nasturtium seeds for next year's garden.

Nasturtiums are prolific producers of seed pods, sometimes referred to as nasturtium berries. Most varieties of nasturtium flowers will produce 1-4 seeds per flower if pollinators are plentiful. The larger the seed, the better it is for saving as large seeds.

If you are growing a mix of nasturtium seeds, they will cross-pollinate through the season, so they may not show true to type when saving seeds to plant next year. If you want to grow a particular heirloom from seed, it is best to isolate the plants from other types or purchase new seeds each year.

Where should you plant nasturtiums?

The short answer is that nasturtium flowers can be planted just about anywhere. They are an excellent addition to flower beds and work great to fill in and cover the fading foliage from early spring bulbs. Since nasturtiums plants are not frost tolerant, they will winter kill and provide an excellent living mulch for your spring bulbs. This frees up the bulbs for late fall and early spring growth without weed competition.

A mix of nasturtiums and cover crops like hairy vetch can be used to slowly overtake and choke out undesirable plants like English ivy under fruit trees. Vining types work wonderfully to grow along fence lines and up trellises to provide shade in the heat of summer. Unlike common trellis flowers like wisteria, vining nasturtiums are not invasive but will self-seed and return year after year. 

Being native to the Americas, they create wonderful pollinator habitats and food wherever they are planted. Hummingbirds and native bumblebees are particularly fond of the plentiful nectar provided in the deep nectaries of each blossom. A favorite summer pastime on our farm is to sit quietly by the nasturtium trellis and enjoy the close flybys of many different hummingbird species. 

Adding nasturtiums to the vegetable garden.

In the vegetable garden, nasturtiums play multiple beneficial roles. Beyond adding beauty and visual interest to the garden:

• They are fabulous for companion planting with crops like brassicas that are prone to aphid infestations. They function as a trap crop and predator attractant. 
• They attract pollinators and other beneficial insects like ladybugs which will lay eggs on the underside of leaves.
• The leaves and flowers are edible and make great additions to garden fresh salads.
• They will self-seed year after year and grow happily in the little-used corners of the garden.

Grow nasturtiums in full sun or partial shade. 

One of the best things about growing nasturtium flowers is their versatility. While the most prominent and healthiest plants will come from plants grown in full sun, they can be easily grown in dappled light as an understory plant. Plants grown in full sun will have more blossoms, those grown in the shade will have more leaves. 

Mixing a few different varieties in shady spots will give you foliage of different shapes and shades of green. Peach Melba, Empress of India, and the Alaska series are great to mix together for a pleasing variety of leaves. 

Do I need to feed my nasturtium plants?

No, nasturtiums prefer somewhat poor soil for ideal flower growth. Soil that is too rich in nitrogen will produce plants with many foliages and not as many blooms. This plant family's ability to grow in just about any type of soil is one of their greatest selling points. So go ahead and throw them in just about anywhere on your property, even those spots that seem to be only good at producing pernicious weeds. 

Eating Nasturtium Flowers, Leaves, and Seeds

Nasturtiums have been grown as a food crop and as an ornamental one throughout the centuries. In fact, it is on record as being planted as a food crop on Thomas Jefferson's farm at Monticello in the year 1774. (1) We can guess they loved the look of the flowers as it was later listed in the ornamental flowers grown on the site. 

All garden nasturtiums produce edible flowers, leaves, stems, and seeds. The fresh seeds can even be pickled like capers. All parts of the nasturtium have a pleasing, sweet, peppery flavor. 

Nasturtium leaves can be eaten at any size. The smaller leaves are often added to salads, while larger ones can be used as wraps for other ingredients. Nasturtiums are frequently used in high-end restaurants and bars for plating.  

The flowers can be used whole to decorate salads and a variety of other foods. The long nectary section of the calyx may be removed if you find that it is harboring ants or other small insects. Nasturtium as a name is also used to refer to a different genus of plants that include watercress. Both Nasturtium and Tropaeolum have similar sweet, peppery flavors. To read more about Cultivating Edible Flowers, including nasturtiums, be sure to check out this resource.  

1. Taken on 2/11/2022 from https://www.monticello.org/house-gardens/in-bloom-at-monticello/nasturtium/