How to Plant and Grow Wallflower

Native to southern Europe, wallflowers are cool-season plants hardy in Zones 3-10 with a lovely fragrance. They come in an abundance of colors. Wallflower is a short-lived perennial or biennial often grown as an annual with a long season of blooms. They vary in size from low groundcovers to small shrubs. Sow wallflowers a few weeks before the last frost date for your region to have them blooming in late spring.

Where to Plant Wallflowers

These plants like well-drained soils so much that they're named for it: Wallflowers can often be found growing out of the mortar between rocks and bricks on the side of a wall. They suit rock gardens, border fronts, raised beds, and containers. They prefer sunny spots.

How and When to Plant Wallflowers

Plant wallflower seeds in the spring, 10 to 12 weeks before the final frost. Where it's warmer, the seeds can be planted in the fall. Don't completely cover them with soil when planting—they need sun to develop.

If you're out of wallflower's hardiness range, plant nursery starts as annuals. Dig a hole about the same width and depth as the planting container. Remove the plant and loosen the roots a bit from the root ball before placing in the hole. Backfill with soil, tamp lightly, and water well.

Wallflower Care Tips

Wallflowers grow best when planted in average, dry to medium, and well-drained soils.

Light

Place wallflowers in an area of the garden where they receive full sun in northern climates. In southern climates, they appreciate some afternoon shade.

Soil and Water

Plant wallflowers in alkaline soil (pH 7.0-9.0) that's well-draining. They need mostly dry soil to keep their roots dry, so they stay healthy. Since they're drought-tolerant, they don't need a lot of watering except when they're first growing. Once they're established, cut back on watering frequency.

Temperature and Humidity

In places where it's warmer, wallflowers can be treated as a perennial, but where it gets cold, they're better used as an annual since their foliage will die back in cooler weather.

Fertilizer

Fertilizing wallflowers is not recommended. Amend the soil with compost when you plant them and they should do fine.

Pruning

Deadhead wallflowers regularly to allow new blooms to emerge. When plants stop blooming, trim them back to half their size in warmer climates, and in cooler climates, cut them to a few inches above the ground when the weather cools.

If you plan on growing them as a perennial, shear them back after the initial bloom to promote dense, bushy growth. If left too long, they become woody and leggy and will produce fewer and fewer flowers. Pruning also prevents plants from reseeding, but you may wish to allow them to set some seeds because they're short-lived.

Potting and Repotting Wallflower

To pot low-maintenance wallflowers, use a well-draining container at least 6 inches larger than the root of the plant. When the roots start to show through the drainage holes, repot to a larger container.

Pests and Problems

Since wallflowers prefer drier conditions than many other plants, they're less susceptible to insects like fleas and cabbage worms. Avoid planting near vegetables to reduce the opportunity for infestation. Diseases that can affect wallflowers include powdery mildew and rust. Neem oil can get rid of powdery mildew, and a weekly sprinkling of sulfur can treat rust.

How to Propagate Wallflower

Propagate wallflowers with plant cuttings. Cut a stem with at least one leaf node, dip in rooting hormone and insert into potting mix after removing all flowers and leaves on the bottom half of the cutting. A 4-inch pot is best. Water and wait for it to pull back when you tug on it, which indicates roots have formed. Then your cutting is ready for planting.

Types of Wallflower

'Bowles Mauve' Wallflower

'Bowles Mauve' is a classic variety with gray-green leaves, pale purple flowers, and a pleasant fragrance. Zones 6-10

'Fire King' Wallflower

Erysimum 'Fire King' bears striking orange-red flowers on 16-inch-tall plants. Zones 3-7

'Orange Bedder' Wallflower

Erysimum 'Orange Bedder' bears bright clusters of orange flowers on compact, 1-foot-tall plants. Zones 3-7

Wallflower Companion Plants

Diascia

Found with increasing frequency in garden centers, diascia is a snapdragon-like flower you can plant early in the spring. It blooms in a wide range of pinks—from cool, bubblegum pinks to warmer peach, coral, and salmon. A perennial in the southernmost states, it's a cool-season annual elsewhere. Plant it a few weeks before your region's last frost for early fall color. Zones 8-11

Snapdragon

Snapdragon is a cool-season annual that blooms in early spring when warm-season annuals are just being planted. The flowers come in gorgeous colors, including variations on each flower. Plus, snapdragons are an outstanding cut flower. They're also great for fall color. Zones 7-10

Stock

Plant stock in spring several weeks before your region's last frost date; this annual thrives in cool temperatures and stops blooming once hot weather arrives. It makes a great cut flower, perfuming bouquets and borders. It grows best in full sun or part shade and moist, well-drained soil. Zones 7-10