Growing nasturtium plants in your dome greenhouse will provide beauty and health benefits; for you and your garden. The flowers and leaves are edible, they are gorgeous companion plants plus they make great fairy flower hats if you have children helping you garden! Nasturtiums make a great cover plant to retain moisture in garden beds and to help prevent weeds.
Family: Tropaeolaceae
Botanical Name: Tropaeolum spp.
Common Name: Nasturtium
Type: Annual, perennial
Zone: 9 to 11 (USDA)
Soil pH: Acidic, neutral, alkaline, pH 6-8
Size: 1-10 ft. tall, 1-3 ft. wide, bigger in a dome
Growing Nasturtiums
Growing nasturtiums is fairly easy. They will happily grow as a ground cover, climb a trellis to provide shade, or add beauty as a hanging plant. They are available in a wide range of colors to add splendor to your greenhouse or garden and keep your beneficial insects happy. Nasturtiums are a good choice for new gardeners.
Best Location in a Dome Greenhouse
Nasturtiums love full sunlight but will grow in partial shade or dappled sun. The big difference is in flower production. If you want more flowers, plant them in full sun. If you are more interested in the leaves for salads or as wraps, dappled sun or partial shade will be fine.
To overwinter nasturtiums, plant them near the pond where it is the warmest in winter.
As a trap crop, plant them near plants that will benefit such as cucumbers and tomatoes.
Planting Nasturtiums
Sow seeds directly when the soil is at least 55 degrees or warmer. Sow seeds ½” deep spaced 10-12” apart. Keep newly planted seeds moist until the seeds sprout.
If you are transplanting nasturtiums, they can be a little fussy. It helps to grow the seedlings in biodegradable pots to help avoid transplant shock.
Nasturtiums come in bush or trailing varieties and all do well in containers. Trailing varieties tend to have larger flowers and leaves and bush varieties tend to produce more flowers. There is some crossover; some bush varieties will trail and some trailing varieties are bushier.
Nasturtium Care
Sunlight: Nasturtiums need 6-8 hours of full sunlight. However, if you live in a very hot region they prefer some shade from the afternoon sun. When planted with less than 6-8 hours of sunlight or shade they will not produce as many flowers.
Soil: Nasturtiums are not picky about the soil they grow in. They actually do better if the soil is infertile. Rich soil will result in beautiful greenery, but fewer flowers. A neutral soil with a pH between 6 and 8 is best for nasturtiums.
Temperature: As a warm-weather plant, nasturtiums prefer daytime temperatures around 70 degrees. Pro Tip: Nasturtium leaves can turn brown in high temperatures if they do not have shade. They can handle a light frost, but will not survive a hard freeze.
Water
Water: A once-a-week watering schedule is best for nasturtiums. You may need to water more frequently if planted in a greenhouse. If planted in a sunny vegetable garden they will need a bigger drink of water as their companions will drink up a lot of the moisture. In drought conditions there will be fewer blooms and the foliage will be leggy. Nasturtiums like humidity, but are very tolerant of dry soil.
Did you know that nasturtium leaves are water-resistant? They are one of the few plants that exhibit the “lotus effect“. Nasturtium leaves hold the water droplets and the leaves are cleansed by the rain. This helps protect the plant from fungi and other diseases that try to adhere to the leaves. It also provides a bathhouse for butterflies and other friends!
Fertilizer: If you plan to grow nasturtiums as an edible crop and grow organically, your soil is most likely fine as it is. Amending your soil may make it too rich and your nasturtiums will grow robust leaves, but few flowers. If you are growing them near vegetables as a trap crop, amend the soil for your vegetables to aim for a good balance.
Nasturtium Companion Plants
Companion plants are a bonus to any garden. Practicing companion planting will offer many benefits. First of all, they attract pollinators and beneficial insects. They help retain moisture and offer weed control. Lastly, they can add nutrition to the soil which increases productivity.
Nasturtiums are companion plants for the following plants: broccoli, cabbage, cauliflower, cucumber, kale, potato, pumpkin, radish, squash, and tomato. The benefits include attracting beneficial insects, a ground cover to help retain moisture as well as preventing weeds, and acting as a catch crop for unwanted pests.
They are wonderful at repelling pests (and rappelling down rock walls and other surfaces). Nasturtium has an amazing superpower; they have an airborne phytochemical that deters whiteflies, some beetles, and other pests away from your plants.
Nasturtiums are very good at attracting pollinators and beneficial insects to your dome greenhouse. Pro Tip: Hoverflies love nasturtiums plus they eat aphids!
Managing Pests
Yellow nasturtiums are very attractive to aphids. (Hmmm, yellow sticky traps?) Plant nasturtiums as a trap crop to help keep aphids off your vegetable crops. To protect your nasturtiums, spray them with a hose to knock those soft-bodied pests off.
If your nasturtium is not planted as a trap crop, plant catnip beside the nasturtium to help repel aphids. Many aromatic herbs will keep aphids at bay.
Another common pest for nasturtiums is bacterial leaf spot. Avoid this by giving your nasturtiums plenty of room for airflow and water with drip irrigation to avoid spreading the disease via splashing water.
Harvesting Nasturtiums
Once the plant is mature, at about six weeks, you can start harvesting leaves and flowers. Use scissors or clippers to harvest to avoid damaging the plant.
To make capers, harvest the green seed pods. Save seeds for planting the next season by collecting the mature seed pods.
Trimming Nasturtiums
Nasturtiums try to take over the world so they require occasional trimming. Both the leaves and flowers are edible so add them to salads or follow the links below for more recipes.
Trimming them in mid-summer and again in late summer will help them to produce more flowers. It is best to use clippers or scissors to trim so the plant is not damaged.
Nasturtium History
Nasturtium plants are native to South and Central America, specifically in the tropical or subtropical forests of the Andes mountains. The ancient Incas understood the value of this beautiful plant both as an edible plant and as a medicinal herb. They harvested wild nasturtium to make teas for respiratory ailments and also as a poultice for cuts and burns.
Spanish explorers brought the seeds from South America to Europe in the 1500s, but they didn’t bring the knowledge of all the benefits of the plant, known as Indian cress at the time. It wasn’t valued in Europe as a food crop or for its medicinal uses until the petals and flowers began being eaten and made into tea in the Orient.
Health Benefits of Nasturtium
Nasturtiums have been used medicinally for centuries. The ancient Incas and native South Americans used the plant for its antibiotic and antibacterial properties while Europeans ate it as a treatment for urinary tract infections.
The leaves and flowers of this lovely plant are power-packed with vitamin C and the stems and leaves have vitamins, and antioxidants; one of which is Lutein. What’s so great about Lutein? We’re glad you asked! Well, for one thing, Lutein helps maintain skin and eye health; which helps us see those gorgeous flowers!
Nasturtiums are full of peppery deliciousness. There are many recipes with nasturtium, here are some of our favorites: Nasturtium Flatbread Pizza or try our Nasturtium Spring Rolls!
Nasturtium Trivia:
- Monet planted nasturtiums along the pathway to his front door in Giverny, France. He thought he planted dwarf nasturtiums until they started creeping over his gravel, but liked the effect so much he planted them every year. He is quoted as saying “My garden is my most beautiful masterpiece.” – Claude Monet
- Did you know that nasturtium seeds were a substitute for pepper during World War 2?
- There is an amazing garden display (plus a video) of hanging nasturtiums at the Isabella Stewart Gardner Museum in Boston.
- Nasturtiums were a staple in kitchen gardens during colonial times.
- The leaves of nasturtiums are water-repellant!
- Nasturtium is known as Indian Cress, Mexican Cress, and Peru Cress.
- The word nasturtium means twisted nose. Wait, what? Twisted nose refers to the effect on the nasal passages while eating peppery nasturtium.
Planting nasturtiums in your dome will bring beauty to your garden beds, benefits to the vegetables in the dome, health benefits to you, and deliciousness to your table!
