How to Grow Nasturtiums from Seed: Easy Edible Flowers for Garden and Table

When I started at Gardener's Supply in the 1990s, my Vermont backyard was mostly lawn. Today, just a bit of original grass remains. Most space now holds trees, shrubs, perennials, annuals, and stonework. Watch a slideshow of my Burlington, VT garden.

I also work at Church Hill Landscapes, maintaining dozens of gardens. I believe all gardening is good gardening.

Not only are nasturtiums beautiful, they're edible.

"What are some easy annuals to start from seed?" When asked, I always include nasturtiums. Seeds are large, can be planted directly in the garden. For earlier starts, plant indoors.

Planting in the Garden (Direct Sowing)

Good for seeds needing little coddling or seedlings suffering transplant shock. For nasturtiums, plant right where they'll grow—no transplanting needed. Wait until frost danger passes. In hot climates, choose a site shaded from hot afternoon sun. Plant seeds 1 inch deep, ~10 inches apart. Can plant closer and thin later. Check seed packet for specifics. Nasturtiums thrive even in poor soil with regular watering.

Mark planting sites with labels to prevent accidental weeding. Distinctive foliage makes seedlings easy to spot.

Planting Indoors

For larger plants and earlier blooms, start seeds indoors.

Cowpots

Large seeds do well in 2¾" or 3" Cowpots. Plant two seeds 1" deep per pot under lights or in a south-facing window. Germination takes 10-12 days. When seedlings have several leaf sets, pinch out the weaker, leaving one per pot. Two seeds insure against germination failure; confident gardeners can use smaller pots with one seed each.

When nighttime temperatures reach the 50s, harden off: move outdoors days, indoors nights. After a couple days, plant in garden. Reduce transplant shock by tearing off Cowpot's top edge and planting pot-and-all. Bury top edge to prevent moisture wicking.

Growing On

Nasturtiums are carefree but need water during dry periods. Thrive in containers and windowboxes. Let soil dry between waterings, but don't let it dry out completely.

Edible flowers taste peppery like watercress. All colors/varieties work in salads or as garnishes. Leaves are edible too.