How to Grow and Care for Wallflower Plants

Wallflower is considered a shrub, groundcover, and bedding plant that blooms well alongside spring bulbs and sprouts pretty blossoms through silty cracks in brick or cement walls, which is how it gets its name. Wallflower grows best in warmer climates and very well-draining soil that dries somewhat quickly. The plant can tolerate very alkaline soil.

Wallflower Care

Here are the main care requirements for growing wallflowers.

• Plant wallflowers in a sunny position that is protected from wind.
• Use well-draining soil that's somewhat gritty with sand or small rocks.
  
• Do not plant in wet, soggy, or poorly draining areas, and do not overwater.
• Space the plants about 10 to 12 inches apart in the ground.

Light

Wallflowers should be grown in a bright, sunny location. While they can tolerate part shade they will thrive in full sun. Gardeners in northern climates should choose locations that receive direct sun, whereas gardeners in southern climates should plant in places that receive some afternoon shade.

Soil

Well-drained, dry to medium-dry soils are ideal for wallflowers. Wallflowers do not tolerate wet feet, or having their roots sit in standing water, so avoid planting wallflowers in particularly wet areas of your garden or in poorly draining soil, which leads to rapid decline and plant death. Wallflowers can grow in very alkaline soils (pH 7.0 to 9.0).

Water

Wallflowers are considered drought-tolerant, and as such, they do not require too much water. Only water wallflowers regularly as they are becoming established, and then cut back once they have matured.

Temperature and Humidity

In warm climates (USDA zones 8 to 10) perennial wallflower varieties grow as evergreens. At the lower end of their hardiness range, they can still be grown as perennials but their foliage will likely die back in the winter. Below their hardiness range, wallflower is usually grown as an annual.

Fertilizer

Wallflowers do not require a lot of fertilizer to thrive and in fact, fertilization is generally not recommended. Instead, mix compost into the soil when you are first planting.

Types of Wallflowers

Most wallflowers are cultivars or hybrids. Notable varieties include:

• E. cheiri 'Sunset Apricot': This biennial wallflower has fragrant, yellow-apricot flowers.
• E. cheiri ' 'Sunset Primrose': An evergreen perennial, these wallflowers start lemon yellow and turn primrose as they age.
• 'Winter Passion' and 'Winter Orchid': Both of these wallflowers belong to the trademarked 'Winter' series of compact and mounding perennial hybrids with large, fragrant flower spikes.
• 'Red Jep': This perennial wallflower type is a hybrid with fragrant red to purple flowers.
• E. linifolium 'Bowles’s Mauve': These perennial wallflowers produce rich, mauve blooms.
• 'Walberton’s Fragrant Sunshine': This trademarked perennial hybrid wallflower produces compact, bushy orange blooms.
  

Pruning

Deadheading is important for keeping wallflowers healthy and full-looking. To encourage ongoing blooming, pinch back spent blooms regularly. Once the plants have finished blooming, or in the early spring in warm climates, prune the stems back by at least half to prevent them from getting leggy. In cooler climates, prune them in the fall so there are only a couple of inches left above the soil, and they will reward you with dense new growth once temperatures warm up again.

Propagating Wallflowers

Before you set out to propagate a wallflower, check whether the variety is trademarked or protected by a plant patent, as the propagation of those plants is prohibited. If that's not the case, wallflowers that are grown as biennials or perennials can be propagated through cuttings in the late spring.

1. With a sterilized, sharp knife or pruner, take a cutting that has at least one leaf node.
2. Remove all flowers and flower buds from the cutting and leave only three to four leaves.
3. Dip the cutting in a rooting hormone and insert it in 4-inch pots filled with potting mix.
4. Water it well and keep it evenly moist until new growth appears.
5. When the cutting does not move when you gently tug on it, it's ready to be transplanted into garden soil or a larger container for a patio or deck.

How to Grow Wallflowers From Seed

Wallflowers grow readily from seed. Here's how:

1. Sow the seeds directly into the garden or start them indoors 10 to 12 weeks before the last frost in your area. In locations with warm winters (USDA zone 8 to 10) you can also start the seeds in the late autumn.
2. The seeds require light to germinate so don't cover them with more than 1/8 of an inch of soil.
3. Make sure to provide adequate light for germination.
4. Wallflowers transplant well once established.

Potting and Repotting Wallflowers

Shrub-type wallflowers make excellent container plants as they are low maintenance and don’t require too much water. Choose a container that is large enough to accommodate the root system plus about 6 inches. Ensure your container has adequate drainage as wallflowers do not tolerate having their roots sit in water. Choose a well-draining potting soil.

Repot the plant when its roots fill the container, or grow out of the drainage holes.

Overwintering

When grown in its hardiness range, wallflower does not need any winter protection although it might drop its leaves at the cooler end of the hardiness range.

Outside of its hardiness range, it is best to grow wallflower as an annual. While you can bring a potted plant indoors for the winter, it might get leggy if you don't have a spot in a bright, south-facing window, or add supplemental grow lights.

Common Pests & Plant Diseases

As a part of the Brassicaceae family, wallflowers are susceptible to a host of common garden pests just like their vegetable cousins. These include flea beetles, aphids, and cabbage worms. However, wallflowers are better suited to dry growing conditions than their Brassicaceae relatives, which inadvertently helps to prevent pest infestations.

Wallflowers may be susceptible to clubroot, a disease that also affects plants in the cabbage family. It is not classified as a fungus or bacteria but it does produce spores. Plants with clubroot will look stunted and wilted, or the roots will look swollen and thickened. There is no other treatment but to pull and compost the infected plants.

Prevent infestations and diseases in wallflowers by ensuring that you are not planting them in a garden bed or container that has recently grown other Brassicaceae species as pathogens may remain in the soil from the previous plant.

How to Get Wallflowers to Bloom

Bloom Months

Wallflowers will bloom from early spring (possibly as early as March) through midsummer months.

What Does Wallflower Look and Smell Like?

Wallflowers are beautiful four-petalled blooms in bright colors such as yellow, orange, red, blue, and purple. Wallflowers are sweetly scented. They make great shrubs and ground covers and are excellent additions to any rock garden, border, or container garden.

How to Encourage More Blooms

Promote more blooms by cutting back the plant every once in a while. Make sure the plants are growing in full sun. Do not fertilize to force the plant to produce more flowers.

Caring for Wallflower After It Blooms

If you live in a warm climate, trim it back to about half and deadhead it (unless you have a biennial variety and would like it to reseed itself). In a climate where it won't survive the winter, the wallflower is usually grown as an annual. The end of the bloom on an annual also means the end of the plant's life cycle so you should discard it.

Common Problems With Wallflower

Wallflower plants are generally easy to grow and low-maintenance. Here are some tips to consider if you notice that the plant is behaving differently than you are used to.

Not Blooming

If you have propagated your own plant, and depending on when you started it, the wallflower might not bloom during the first year. A plant purchased from a nursery, on the other hand, should bloom the first year. If it doesn't, it is most likely due to lack of sun, as a wallflower plant needs full sun to bloom at its best.

Becoming Leggy

If wallflowers look leggy, the plants need to be shaped up through pruning. Do this after they bloom in the spring or summer by pruning the stems by half.

Wilting and Limp

Wallflowers may prematurely wilt if they contract clubroot or if they are overwatered. Check for clubfoot. If overwatered, cut back on moisture to see if the plant rebounds in a couple of weeks.