How to Grow Nasturtiums: Edible Flowers

Of all the flowers you can grow, nasturtium (Tropaeolum majus) is one of the most rewarding. It thrives in USDA zones 3 to 11, asks for full sun, and goes from planting to harvest in roughly 50 to 60 days. The short version of success: flowers and leaves are edible with a peppery bite. poor soil means more blooms; rich soil means all leaves.

Below is the whole season laid out plainly: which variety to pick, when to plant for your zone, how to feed and water, what troubles to watch for, and when to harvest. For the botanical background, the Missouri Botanical Garden keeps a detailed plant profile worth a look.

Is nasturtium worth the space? For most American gardeners the answer is yes, and here is why: a fast payoff by garden standards: roughly 50 to 60 days from planting to harvest. Few other plantings turn a packet of seed into this much food or color this quickly. It fits zones 3 through 11, which covers nearly the whole country. Frost-tender annual; dislikes transplanting.

Photo: Wikimedia Commons

At a Glance

• Botanical name: Tropaeolum majus
• Type: Flower
• USDA zones: 3 to 11
• Sun: Full sun
• Soil: Poor, well-drained soil
• Water: Moderate
• Spacing: 10 inches apart
• Planting depth: 3/4 inch deep
• Days to maturity: 50 to 60 days
• How to start: Sow directly where it will grow

Choosing a Variety

Bush types form tidy mounds for edging and pots. Climbing types scramble six feet up a trellis or spill from hanging baskets. Alaska series has variegated leaves that brighten shady corners. Single flowers feed pollinators; doubles look showier in bouquets. All have the same peppery edible flowers and leaves, so choose by habit and color. In hot climates, give afternoon shade to extend the season. Sow seed directly where you want them — nasturtiums sulk when transplanted. Our guide to growing marigolds pairs well with this one if you are planning the bed. For variety trial notes in plain language, the Missouri Botanical Garden is a reliable read.

When and How to Plant

Timing is half the battle with nasturtium. Sow seed directly about 1 weeks after your last spring frost, once the soil has warmed.

Your exact dates depend on your zone, so check your USDA zone planting dates on our planting calendar before you sow a thing. The Almanac planting calendar is another handy date reference.

Give each plant room: 10 inches apart, in soil loosened at least 8 inches deep. Sow or set plants 3/4 inch deep. Frost-tender annual; dislikes transplanting. The Gardenia carries regional timing notes for nasturtiums if you want a second source.

Soil and Sun

Nasturtium wants full sun — fewer hours means weaker plants and smaller harvests. Poor, well-drained soil is the target; work in 2 to 3 inches of compost before planting and skip it only if your ground is already rich and dark.

If your soil is heavy clay, plant in raised beds or mounds where water drains freely. A simple soil test from the National Agricultural Library resources or your state extension tells you pH and nutrients cheaply; the Clemson Home and Garden Information Center explains what nasturtiums need most.

Watering and Feeding

Water nasturtium by this rule: moderate. In practice that means soaking the root zone deeply once or twice a week rather than sprinkling daily — shallow daily watering trains roots to stay near the surface, where they dry out fast.

A 2- to 3-inch mulch of straw, shredded leaves, or bark holds moisture, cools roots, and cuts weeding. Keep mulch a couple of inches back from stems. The UF IFAS Gardening Solutions has good watering guidance for nasturtiums.

Feed lightly. Most nasturtiums do well with compost at planting plus one mid-season side-dressing of balanced fertilizer. Overfeeding grows lush leaves at the expense of fruit, flowers, or flavor — more food is not more harvest.

Care Through the Season

Through the season, nasturtium mostly needs watching rather than fussing. Water moderately and otherwise leave them alone; nasturtiums thrive on neglect. They famously attract aphids, which makes them an excellent trap crop planted near roses or vegetables; simply pull and discard badly infested plants. Flea beetles may chew seedlings, so protect young plants with row cover if needed. Stay ahead of weeds early; once plants size up, their own shade does the work.

One more habit worth building: flowers and leaves are edible with a peppery bite. poor soil means more blooms; rich soil means all leaves. Gardeners who do this one thing report far fewer disappointments. If you grow calendula too, our guide to growing calendula covers companion timing that pairs well here. The USDA PLANTS database pest guides identify most culprits with clear photos.

Weeds are the quiet thief in a nasturtium bed — they steal water, light, and nutrients while you are not looking. Hoe shallowly when weeds are small; deep hoeing damages roots. A fresh mulch layer after the soil warms suppresses most of them for the rest of the season.

Season by Season

Spring is for planting: Sow seed directly about 1 weeks after your last spring frost, once the soil has warmed. Prepare the bed with compost as soon as the ground can be worked, and harden off indoor seedlings for a week before they move out. Summer is for water, mulch, and watching: keep soil evenly moist, keep weeds down, and check weekly for pests. Harvest begins as soon as crops ripen — and picking often keeps plants producing. Fall is for the last harvests and cleanup: In mild-winter areas, a late planting can carry the harvest into cool weather; elsewhere, finish up before hard frost. Pull spent annuals, compost healthy foliage, and sow a cover crop or mulch bare beds. Winter is for planning. In winter, rest: clean tools, order seed early for the best selection, and sketch next year’s bed plan while the garden sleeps.

Harvest

Harvest time is the payoff. Pick nasturtium at its peak and handle it gently — flavor and storage life are decided in these small moments.

Pick the bright flowers and round leaves daily for salads, where they add a peppery, watercress-like bite. The flowers keep best picked in the cool of morning. Pro tip: let some flowers form their fat, ridged seeds, which can be pickled like capers or dried and saved; they stay viable for several years. While you are at it, our guide to growing zinnias covers harvest timing for a classic companion crop. The Old Farmer’s Almanac harvest charts give backup timing by region.

Storing and Preserving the Harvest

Cut nasturtiums last longest when you treat them right from the stem up. Cut in the cool of morning, strip any leaves that would sit below the waterline, and place stems in clean water immediately — a long drink before arranging doubles vase life. Recut stems every few days and change the water; cloudy water means bacteria, and bacteria mean wilt. For seed saving, let a few of your best flowers dry fully on the plant, then collect seed on a dry day and store it cool, dark, and dry in labeled envelopes. Home-saved seed of open-pollinated varieties grows true and costs nothing. Leave some spent flowers standing into fall too — the seed heads feed birds and give the garden winter interest.

Troubleshooting

Aphids love nasturtiums — that is the trap-crop bargain; pull badly infested plants. Flea beetles chew seedlings — use row cover. All leaves and no flowers means too much fertilizer. Whiteflies in greenhouses — ventilate well. When in doubt, the National Agricultural Library runs a plant-problem diagnostic worth bookmarking.

Frequently Asked Questions

How long does nasturtium take to grow?

About 50 to 60 days from planting to harvest, depending on variety and weather. Warm seasons and good soil hit the early end of that range.

Can I grow nasturtium in containers?

Yes — nasturtium suits containers well. Use a pot at least 12 inches wide and deep with drainage holes, good potting mix, and a sunny spot. Pots dry fast, so check water daily in summer.

What is the hardest part of growing nasturtium?

Flowers and leaves are edible with a peppery bite. Poor soil means more blooms; rich soil means all leaves. Master that one point and most other problems never show up.

When should I plant nasturtium?

Work backward from your frost dates: Sow seed directly about 1 weeks after your last spring frost, once the soil has warmed. Check your USDA zone planting dates on our planting calendar to pin down your exact window.

References

Lady Bird Johnson Wildflower Center. (n.d.). Tropaeolum majus. Native Plant Database. https://www.wildflower.org/plants/

Missouri Botanical Garden. (n.d.). Tropaeolum majus. Plant Finder. https://www.missouribotanicalgarden.org/

Clemson Cooperative Extension. (n.d.). Nasturtium. Home & Garden Information Center. https://hgic.clemson.edu/

U.S. Department of Agriculture. (n.d.). Tropaeolum majus. National Agricultural Library. https://www.nal.usda.gov/