Organic gardens and regenerative practices help our environment to thrive and heal. One such plant that stands out in the world of regenerative gardening is the Nasturtium.
In this guide, you’ll learn about how nasturtium is the Queen of Organic Gardening, and how it can help improve your vegetable harvest and enliven your landscape with an array of beneficial insects.
Plus, it’s pretty and edible, too!
Nasturtiums, known scientifically as Tropaeolum majus (climbing) and Tropaeolum minus (dwarf), boast a color spectrum that ranges from delicate pale yellows to rich, fiery reds, including the enchanting new rose-pink varieties.
Edible Flowers: Fully edible from leaf to bloom, these peppery delights add a burst of flavor and color to any dish, with the added perk of their vitamin C-rich composition, historically celebrated for scurvy prevention (Curtis’s Botanical).
Nasturtiums are also prized for their levels of potassium, phosphorus, calcium, magnesium, zinc, copper, and iron (Jakubczyk).
Soil Saviors: Nasturtiums are not fussy about soil quality; in fact, they're known to improve it. Their vigorous roots break up compact soil to enhance structure and fertility for nearby plants (Garden History 1985).
Pest Patrol: A study from Iowa State University found that nasturtiums planted near squashes reduced squash bug damage!
Plant type: Edible flower, ornamental, pollinator plant
Growing habit: Annual
Days to Maturity: 65
Country of Origin: Peru
The Tropaeolum genus has been stewarded as an edible and ornamental crop by the Indigenous peoples of the Andes for centuries, especially in the area of Lima (Cultivariable).
These vibrant plants are more than just eye candy; they are biodiversity boosters. They attract beneficial insects like pollinators to create a balanced ecosystem.
Nasturtiums are a magnet for bees and butterflies, which are vital for pollination and the health of many plant species.
I often need to check my nasturtium flowers before I pick them, as it’s common for me to find a bee happily buzzing away inside the trophy-shaped blooms.
Nasturtiums are an excellent hummingbird attractant, especially the red variety (UC Master Gardeners).
Nasturtiums have a very high nectar-sugar concentration of 34% (Biotropica).
A scientific study published in The New Phytologist highlights an important phenomenon in flowers related to climate change. Under conditions of increased heat and drought stress, many flowers will produce less nectar. This likely would lead to a food source crisis for important pollinators in our ecosystem.
Interestingly, nasturtium (Tropaeolum majus) is impacted differently when it comes to elevated CO2 levels. Its nectar production actually increases under these specific conditions. This suggests that nasturtium could become an important plant for pollinators as atmospheric CO2 levels rise.
Nasturtiums either climb or “spill over," so they are easy to fit in among vegetables, especially along the edges of beds or along fencing. A polyculture with flowers, herbs, and varied plantings is always healthier than a monoculture.
Companion planting involves placing two different plants in proximity to benefit one or both plants, often for insect damage control, nutrient management, or microclimate adjustment.
Nematode Prevention
The tuberous nasturtium, known as Mashua (Tropaeolum tuberosum) is a large part of the traditionally Andean diet in South America.
An article in Mountain Research and Development states that mashua contains nematocidal and insecticidal components can are helpful for pest control in the garden.
Nasturtiums are mentioned as part of a study on companion planting conducted by Iowa State University.
The study investigated the effectiveness of nasturtium, among other plants, as a companion plant to common garden vegetables (tomato, lettuce, broccoli, zucchini, and cabbage).
It was found that companion plant plots experienced less damage from pests compared to single-species control plots. This suggests a general benefit to a diverse mixture of species.
Specifically for nasturtiums, the study showed that they reduced the population of squash bugs when planted near zucchini.
Gardeners who face challenges with zucchini and other squashes due to high insect pressures might find it beneficial to plant nasturtiums nearby to help mitigate the damage caused by these pests.
Pam Zaklan, president of the OSU Extension Service has a theory that the yellow flowers of nasturtium look like the yellow flowers of squash, and the pests are distracted and leave the crop plants behind.
In addition to vegetables, marigolds can pair well with nasturtiums. This flower complements nasturtiums in pest control, especially against nematodes that can damage various vegetable roots.
While there are other common companion plantings suggested with nasturtiums, such as aphid deterrents or support for tomatoes, what I've outlined here is the extent of what I found from actual scientific studies.
The genus name “Tropaeolum” means “little trophy”, and Nasturtium certainly wins plenty of awards for its beauty and practicality in the regenerative garden.
Nasturtiums aren't just beautiful; they are entirely edible. From the peppery leaves to the vibrant flowers, they add a splash of color and flavor to meals.
I love to add a handful of nasturtium flowers towards the end of cooking a stirfry. The petals don’t hold up well under the heat, but the flavor definitely comes through!
For more beauty on your plate, try the flowers in a salad.
The seedpods can be pickled and used like capers in caponata, too!
A recent 2023 study uncovered a natural way to protect plants from the tobacco mosaic virus (TMV) with a special liquid made from nasturtium seeds. TMV can attack all sorts of plants, even ones in your garden.
The interesting results of this study showed that when plants are sprayed with this nasturtium seed hydrosol, they become super-resistant to TMV.
This is a big deal because it's tough to find safe, non-chemical ways to stop plant viruses.
Nasturtium hydrosol could change how we keep plants disease-free. It's eco-friendly and could help farmers and gardeners keep their plants healthy without the harmful side effects of synthetic chemical treatments.
Nasturtium hydrosol could be a powerful new addition to our plant care arsenal to fight off plant viruses sustainably.
Notably, if you find aphids on your nasturtiums, this is a sign that your soil has a lime deficiency. In this way, you can understand how to amend your soil for improved crop production (Curtis’s Botanical).
Nasturtiums have a reputation for being tough as nails and can improve the soil they inhabit.
They are great to grow if you need to establish a new garden on poor soil, because they will grow under almost any conditions. Pretty much anywhere you plant them, they will grow (Garden History 1985).
As a bonus, their roots break up compacted earth to enhance soil structure and fertility. This helps the surrounding plants to have better water access and root growth
In this way, nasturtiums create a supportive ecosystem for a variety of plant species.
If you have an area of your garden with bare soil, or want to fill in empty spot before your other plants come into maturity, nasturtiums are a great way to protect the soil.
Nasturtiums as a living much helps to reduce soil erosion and nutrient wash-out, and keeps the soil cool in the heat of summer. The shade from the leaves will decrease water evaporation, too.
As a bonus, this living mulch helps reduce weed growth.
Nasturtiums can be planted as a warm weather cover crop to enhance the nutrient cycle of the soil. Trailing and climbing nasturtium varieties are great for their ability to generate a large quantity of biomass for green manure.
Nasturtiums release nitrogen, phosphorus, potassium and minerals back into the soil as they decompose.
This hardy plant requires minimal attention. It thrives in poor soil and thrives without fertilizer. In fact, high soil nutrition will make the plant grow lots of leaves with not very many flowers.
The perfect addition to a water-wise garden, they don’t require tons of rainfall to thrive, either.
My chickens absolutely love nasturtium flowers and leaves. I will cut back my nasturtium plants significantly if I see that they are littered with pests. I put the plant material and pests in a bucket, and bring this tasty treat to the chickens. They love the plants and the bugs, and now the pest population in my garden is controlled. It’s win-win-win!
With this method, the nasturtiums will regenerate as long as I leave about 20% of the plant material behind. I also have multiple nasturtiums planted around my garden, so their benefit never disappears during the growing season.
Mashua is one of the core root crops of the Andean region, and it can produce high yields of nutritious tubers. As part of the brassica order, it’s not surprising that these have a slight turnip taste when cooked (Cultivariable).
Mashua does need lower summer temperatures to grow, and can be a helpful staple crop for those living at altitude with cooler summers. In the villages of the Andes at high altitude, high temperatures are an almost constant 60F year-round.
Planting Justice recommends mashua be planted in part shade to help keep temperatures cool. Another idea would be to create an overhead arch of climbing flowering nasturtiums to produce shade cover for the tuberous variety.
Importantly, however, mashua is a great regenerative permaculture crop if you have cool summers, because it does not need much input for success (Rain Tree Nursery).
Additionally they do not suffer from poor soil.
It perennializes in zones 8-12, but can also be grown as an annual in gardens that do not receive many heavy frosts before November (Strictly Medicinal Seeds).
Nasturtiums are wildly easy to grow, but there are some tips to keep in mind to optimize their health in your garden.
Lightest creamy yellow: Milkmaid (mounding); Moonlight (climbing)
Gorgeous Mauve flowers with ombre petals: Ladybird Rose
Almost Purple Pink: Purple Emperor
Mid-Pink: Salmon Mousse
Solid Magenta Pink: Cherries Jubilee
Vibrant Orange: Spitfire
Solid Red: Empress of India
Darkest Solid Scarlet: Black Velvet
Mix of Rose Pink, Peach, Yellow tropical tones: Aloha Mix
Mix of Yellow, Orange, and Red with variegated leaves: Alaska Mix
Living Mulch/Soil Coverage: Trailing Nasturtium
Trellising/Shade: Moonlight Climbing Nasturtium
Container Gardens: Little Firebirds
Edible Tubers: Tropaeolum tuberosum, known as Mashua in the Andean regions of South America, provides an easy to grow low-input crop.
Nasturtium is more than just a pretty face in the garden. It's a workhorse that embodies the spirit of regenerative agriculture. If you're looking for a plant that can both beautify your space and contribute to a healthier planet, nasturtium is the choice for you. Remember, every plant in your garden can play a part in the larger picture of environmental stewardship. Happy planting!
