How to Grow Nasturtiums

The nasturtiums planted in the cement blocks of my garden border are a familiar and much loved part of my winter garden. Learn how to grow nasturtiums, and add bright pops of color to your garden (and spice to your salad) with this easy-to-grow edible flower.

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7 Tips For How To Grow Nasturtiums

Follow these 7 tips to learn how to grow nasturtiums, and keep reading to learn how to grow nasturtiums in Arizona.

1. Plant nasturtiums at the right time

Start nasturtium seeds indoors 4 to 6 weeks before the last frost, and wait to plant outside until all danger of frost is past. 

Alternatively, large nasturtium seeds are simple to plant, and it’s easy to direct sow nasturtiums in the garden.

Sow seeds in the garden 2 weeks before the last frost. Plant seeds ½ to 1 inch deep and 5-6 inches apart. 

For square foot gardening, plant 1 per square.

In the low desert of Arizona, plant nasturtiums from October through January. 

2. Choose the right location to plant nasturtiums

Grow nasturtiums in moist well-drained soil. Water well until plant is established and then provide regular water.

Nasturtiums prefer cooler weather, so in warm climates grow plants in partial shade (4-6 hours of sun) to prolong their growing season. In cool climates, plant nasturtiums in full sun.

This adaptable plant grows well in shady areas, poor soil, dry conditions, and areas where other plants may not grow.

Nasturtiums are frost-sensitive; you may need to cover them during a frost event. 

3. Choose the best type for your location

Nasturtiums come in a range of colors and varieties including trailing, vining, and bush. 

Trailing varieties make an excellent ground cover in shady spots and areas with poor soil. Trailing types can also be trained along a fence, cascade down from a container, or fill in a border. 

Dwarf varieties grow low to the ground and are more mounded. Grow them where space is limited or in containers. 

4. Encourage blooms

If you want an abundance of flowers, do not fertilize nasturtiums. Nutrient-rich soil grows plenty of green leaves, but not as many blooms. 

Removing faded blooms also encourages more flowers. Trim back container-grown nasturtiums to keep the plant tidy and producing flowers.

The two photos above are of the same area of my yard in different years, but in the second image the seeds were planted in rich compost. We had an abundance of leaves that year, but not a lot of blooms.

5. Grow nasturtiums as a companion plant

Nasturtiums are a great way to prevent pests organically. For instance, nasturtiums help repel squash bugs, whiteflies, and borers.

Tomatoes, radishes, squash, and fruit trees benefit from nasturtiums planted nearby. Nasturtiums are a ‘trap crop’ (insects feed on and lay their eggs in trap crops, instead of in other areas of the garden).

6. Don’t forget, nasturtiums are edible!

The flowers, leaves, and stems of nasturtiums are all edible. They have a fresh peppery taste and can be quite spicy! To harvest blooms and leaves for eating, pick early in the day (but after the dew dries). 

To keep flowers fresh longer, immerse in cold water for about 10 minutes immediately after picking. Use flowers and leaves immediately, or store them in the refrigerator in a damp paper towel. The unripe seed pods can be pickled for a tasty caper substitution.  

7. Save seeds to share and plant

Each flower sets several seeds, and nasturtiums will self-seed easily year after year. At the end of each season, collect extra seeds from the ground to save and share, or plant in other areas. 

The large seeds are easy to collect. I often enlist my kids and their friends to collect the seeds for me (the going rate in my garden is 1 cent per seed). For more information, read this post about saving seeds. 

Bonus Tip: How to grow nasturtiums in Arizona

• Plant nasturtiums directly in the garden from October through January in the low-desert of Arizona.
• You can expect blooms from about February through May. 
• Nasturtiums planted in shaded areas will last a little longer (into May) than those planted in full sun. 
• Nasturtiums thrive in cool winters. If we get a frost event for a day or two, cover them with frost cloth and they may survive.  

Want to add more color to your garden with flowers?

Flowers to Plant Outside & Seeds to Start Indoors Each Month in the Low Desert of Arizona.
• PLANTING GUIDE: Each month lists annual flowers and bulbs to plant outside & seeds to start indoors.
• BLOOMING GUIDE: Photos show what may be in bloom that month.

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