How to Grow Nasturtiums: Planting, Care, and Harvesting

Nov 04, 2026by David Schulze

Nasturtiums combine bright flowers, rounded leaves and a relaxed growing habit in one versatile garden plant. Compact varieties brighten borders and containers, while trailing selections spill over edges or climb with guidance. Their peppery flowers and tender leaves can also add flavor and color to food when the plants are correctly identified and grown for edible use.

This guide covers common garden nasturtiums, especially Tropaeolum majus and related garden selections. They are not watercress, despite the botanical genus name Nasturtium being used for watercress. Check the packet for your variety's size and growth habit.

Choosing Bush or Trailing Nasturtiums

Bush types: Compact plants suit small beds, borders and pots. Give them room to spread rather than crowding them tightly.
Trailing types: Longer stems can spill from containers, cover a garden edge or grow up a suitable support with guidance.
Climbing selections: Provide mesh, slender supports or a trellis that the leaf stalks can grasp. They do not cling directly to a flat wall.

Use the variety's mature spread when planning the bed. A small seedling can eventually cover much more ground than expected.

Choosing a Growing Site

Nasturtiums generally flower best in sun, but afternoon shade can help in hot climates. Choose well-drained soil and avoid persistently wet locations. In Texas, a site with morning sun and some protection from intense afternoon heat can be useful.

Average soil is usually sufficient. Avoid heavy feeding and excessive nitrogen, which can produce abundant leaves with fewer flowers. Poor, dry soil is not the goal either: plants still need enough moisture and nutrients for healthy growth.

When to Plant Nasturtiums

Direct sow after the danger of frost has passed and the soil has begun to warm. Nasturtiums prefer mild growing weather and may decline during extreme summer heat, even with adequate watering.

For Texas gardens, plan around your local frost dates and heat patterns rather than a single statewide date. Spring is a practical starting season in many areas. A later planting may provide fall color where enough mild, frost-free growing time remains. Mild-winter areas may have additional planting windows; use local Extension guidance.

If starting indoors, sow about two to four weeks before your expected transplanting date. Avoid holding plants too long in small containers, since they do not appreciate unnecessary root disturbance.

How to Sow Nasturtium Seeds

Prepare the bed: Remove weeds and loosen the soil where roots will establish. For pots, use fresh, well-draining potting mix.
Sow at the right depth: Plant about 1/2 to 1 inch deep, following the packet's directions for your seed.
Water gently: Keep soil evenly moist during germination without leaving it waterlogged.
Allow time for emergence: Seeds often sprout in about one to two weeks under suitable conditions, though temperature and moisture affect timing.
Thin seedlings: Many compact varieties need roughly 10–12 inches between plants, while larger trailing selections may need more room. Follow packet guidance.

A brief overnight soak in room-temperature water may be suggested on some packets, but it is not universally necessary. Follow the supplier's instructions and avoid prolonged soaking. Direct sowing is often the simplest way to establish plants without disturbing their roots.

Transplanting Indoor-Grown Seedlings

Use individual containers so root balls can be moved intact. Provide strong light after emergence, and harden seedlings off gradually before planting outside. Wait until frost danger has passed.

Plant at approximately the same depth the seedling grew in its container, handle roots gently and water thoroughly. Give plants temporary protection from harsh afternoon sun while they adjust.

Watering and Feeding

Maintain consistent moisture while seedlings establish. Once plants are growing, water deeply when the soil begins to dry, adjusting for rainfall, temperature and soil type. Containers need more frequent checks than beds.

Water at the soil surface when practical. Avoid leaving roots saturated or allowing plants to wilt repeatedly. A light mulch around established plants can reduce weeds and conserve moisture; keep it away from the stems.

Do not apply high-nitrogen fertilizer in an attempt to force flowers. Use a soil test for beds and modest, label-directed feeding for containers when needed.

Managing Summer Heat and Encouraging Flowers

Nasturtiums can struggle when temperatures remain very high. Afternoon shade, consistent root moisture and good drainage can reduce stress, but they cannot guarantee a summer-long display in every Texas location.

Remove faded flowers for a tidier appearance and to reduce seed formation. Trim damaged or excessively wandering stems with clean snips. Leave healthy foliage to support new growth.

If plants produce many leaves and few flowers, consider excess nitrogen, insufficient sunlight, plant maturity and weather before changing fertilizer. Sometimes a fresh planting timed for milder weather is more effective than trying to revive declining plants in extreme heat.

Growing Nasturtiums in Containers

Use containers with drainage holes and enough space for the mature variety. Bush types suit pots, while trailing types work well in large planters or hanging baskets that can support their spread.

Place containers where plants receive suitable light without excessive reflected heat. Check moisture frequently, and do not leave pots standing in water. Install a support at planting time if you want vines to climb rather than trail.

Pests and Practical Companion Planting

Inspect tender shoots and leaf undersides for aphids, caterpillars and other pests. Rinse aphids from sturdy plants with water or remove badly affected growth when practical. Identify chewing insects before deciding whether treatment is necessary.

Nasturtiums are sometimes described as a trap crop, but attracting pests does not automatically protect neighboring vegetables. A trap-crop planting needs monitoring and management so pests do not simply build up and spread. Treat companion planting as one part of garden observation, not a guarantee of pest control.

If harvesting for food, use only pest-control products labeled for the edible crop and follow all restrictions and harvest intervals. Avoid spraying flowers while pollinators are visiting.

Harvesting Edible Flowers and Leaves

Harvest only correctly identified edible garden nasturtiums grown with food use in mind. Do not eat flowers from unknown ornamental plants or plants with an uncertain pesticide history. Never eat seed sold for planting.

Pick fresh flowers during the cooler part of the day, after dew has dried, and choose clean, tender leaves. Check for insects, rinse gently as needed and pat dry. Harvest lightly from young plants and leave enough healthy foliage for continued growth.

The flowers and leaves have a peppery flavor. Use small amounts in salads, sandwiches or as a fresh garnish. Keep this as a garden-to-kitchen accent rather than a reason to strip the plants. Refrigerate harvested material promptly in a clean container and use it soon for the best quality.

Collecting Seeds for Next Season

To save planting seed, let selected healthy seed clusters mature. Mature seeds become firm and often loosen or drop from the plant. Collect them before they are lost, and spread them in a dry, airy location to finish drying.

Store fully dry seed in a labeled container in a cool, dry place. Do not confuse green seeds harvested for a culinary preparation with mature, dried seed intended for storage. Seeds from mixed plantings or hybrids may produce plants that differ from the parents.

Remove developing seeds where unwanted volunteers are a concern, and pull seedlings that appear outside the planned planting.

End-of-Season Care

Garden nasturtiums are commonly grown as annuals in frost-prone regions. Frost or severe heat can end their display. Remove diseased material, clean containers and plan the next sowing for a suitable local season.

Self-sown seedlings may appear when conditions improve, but those are new plants. In frost-free climates, persistence varies with the selection and growing conditions.

Frequently Asked Questions

Do nasturtiums need a trellis?

Bush types do not. Trailing and climbing types can spill over an edge or use a suitable support, depending on how you want them to grow.

Why do my nasturtiums have leaves but no flowers?

Too much nitrogen, too little light, plant immaturity or stressful weather can reduce flowering. Check growing conditions before adding fertilizer.

Can nasturtiums grow in shade?

They tolerate partial shade, especially where afternoon heat is intense, but deep shade generally reduces flowering.

Do nasturtiums come back every year?

They are usually grown as annuals in frost-prone gardens. Dropped seeds may produce new seedlings when conditions are right.

Are nasturtiums good cut flowers?

They can be used in small, informal arrangements, but their delicate flowers and shorter stems are not as durable as many dedicated cutting flowers. Cut fresh stems in cool weather and place them promptly in clean water.