Nasturtium in Zone 8A — Texas

Nasturtiums are a fantastic addition to any Texas garden. Their peppery flavor brightens salads and the vibrant flowers add a splash of color to your garden beds. Plus, they're incredibly easy to grow, offering a high reward for minimal effort in our unpredictable weather.

Even with the extreme heat and unpredictable weather we face here, nasturtiums thrive with the right timing. Our long growing season, nearly 260 days in Zone 8A, gives you plenty of opportunity to enjoy these beauties.

Starting nasturtiums indoors is possible, but honestly, direct sowing is the way to go in Texas. Nasturtiums don't love being transplanted, and with our long growing season, you're better off sowing directly into the ground.

If you *really* want to get a head start, you can start seeds indoors in early to late February, about four weeks before you plan to transplant. Use seed trays with good drainage and provide warmth and plenty of light. Bottom watering helps prevent damping off.

Keep in mind that Texas springs can be early, so watch the weather carefully and be ready to adjust your transplanting schedule if needed.

Transplant your nasturtium seedlings outdoors in mid-March through early April, after the last expected frost. Before transplanting, harden off your seedlings by gradually exposing them to outdoor conditions for about a week. This will help them adjust to the Texas sun and wind.

Space your transplants 10-12 inches apart. Keep an eye on the weather forecast – those late cold snaps can still happen, so be prepared to cover your seedlings if necessary.

Direct sowing is the preferred method for nasturtiums in Texas. Sow your seeds directly into the garden from mid-March through mid-September. This gives you a long window of opportunity to get them established.

Choose a spot with full sun to part shade. Prepare the soil by loosening it and removing any weeds. Nasturtiums aren't picky about soil, but good drainage is essential. Plant seeds about ½ inch deep and space them 10-12 inches apart. They need soil temperatures of at least 55 degrees to germinate.

Nasturtiums are drought-tolerant and thrive in slightly dry conditions, which makes them perfect for Texas gardens. Overwatering is a common mistake that can lead to more leaves than flowers.

During the spring and fall, when temperatures are milder, water only when the top two inches of soil feel dry to the touch – use the finger test. In the heat of the Texas summer, you might need to water once a week, providing about an inch of water each time if rainfall is scarce. Water at the base of the plant to avoid wetting the foliage, which can encourage fungal diseases, especially with our variable humidity.

Signs of underwatering include wilting leaves and stunted growth. Overwatering can cause yellowing leaves and root rot.

A light layer of mulch around your nasturtiums can help retain moisture and suppress weeds, but avoid heavy mulching, as it can keep the soil too wet.

You can expect your first nasturtium harvest from early May through mid-November, about 55 days after planting. Both the flowers and leaves are edible, so harvest them as needed.

Pick the flowers when they are fully open for the best flavor and visual appeal. For the leaves, snip them off with scissors or pinch them off with your fingers. To harvest seeds for pickling, wait until the pods are plump and green.

Regular harvesting encourages continued production. As the first frost approaches in mid- November, harvest any remaining flowers and leaves. You can also collect the seed pods for pickling.

Here are the top three common problems with nasturtiums in Texas:

Aphids

• What it looks like: Clusters of tiny green, black, or white insects on stems and undersides of leaves. Leaves may be distorted or sticky.
• What causes it: Aphids are attracted to stressed plants. In Texas, the extreme heat and drought can weaken plants, making them susceptible.
• How to fix/prevent it: Nasturtiums are often used as a trap crop for aphids, drawing them away from other plants. You can blast aphids off with a strong stream of water from the hose.

Cabbage Caterpillars

• What it looks like: Holes in leaves, often with green droppings nearby. You might see small green caterpillars on the plant.
• What causes it: Cabbage white butterflies lay their eggs on nasturtiums, and the caterpillars hatch and feed on the leaves.
• How to fix/prevent it: Handpick caterpillars off the plants.

Black Fly

• What it looks like: Small black flies clustering around new growth. Stunted or distorted growth.
• What causes it: These flies are attracted to plants with tender new growth.
• How to fix/prevent it: Similar to aphids, a strong stream of water can dislodge them.

Texas-Specific Challenges: The hot-to-extreme heat and variable humidity of Texas can stress nasturtiums, making them more susceptible to pests and diseases. Ensure adequate watering, especially during dry spells, but avoid overwatering.

Nasturtiums make great companions for several plants in your Texas garden. They attract beneficial insects and can even deter some pests.

Good companions include tomatoes, cucumbers, squash, broccoli, and cabbage. They help repel pests that might otherwise attack these vegetables. Nasturtiums act as a trap crop, drawing pests away from your more valuable plants.

Avoid planting nasturtiums near . There are no known bad companions for nasturtiums.