Smaller and more refined than regular hollyhocks (Alcea rosea), zebra hollyhocks (Malva sylvestris "Zebrina") grow 2 to 4 feet tall and half as wide. Although not true hollyhocks, they are related plants and share the same trumpet-shaped blooms that attract hummingbirds and butterflies. Zebra hollyhocks have 2- to 3-inch-wide, lavender-pink flowers with purple throats and pronounced purple veins that give them their common name. They're a good choice for sunny perennial borders and for hummingbird gardens. Also called zebra mallows, these plants are hardy in U.S. Department of Agriculture plant zones 4 through 8. I live in Las Vegas zone 9b and I have no trouble growing Malva and it comes back every year as a sturdy little bush.
Zebra hollyhocks can bloom as early as May in warmer climates and as late as July in zone 4 to 5. They give good color and bloom to the late summer garden when other plants die back. Plants grow 18 to 45 inches tall in clumps that spread through perennial root systems and by self-seeding. The lavender flowers with deep purple stripes bloom from June into late October. Plant zebra hollyhocks in perennial flower beds, rock gardens, cottage gardens and border areas. The long-blooming flowers attract birds, bees and butterflies to the garden.
Planting Instructions Grow zebra hollyhocks in full sun for the best flower production. They'll tolerate partial shade, but the plants will lean toward the light, so stake them to keep them upright. They'll need at least five or six hours of sunlight daily to bloom well. Amend the soil in the site with organic material such as compost or aged manure. Like true hollyhocks, zebra mallows are heavy feeders and grow best in rich, loamy soil. Spread a 2-inch layer of organic material over the planting area and mix thoroughly into
Check the soil pH with a test kit or pH meter after mixing in the soil amendments. Malva grows best in soil with a pH of 7.0 or a bit higher, which is neutral or slightly alkaline. If the soil is below 7.0, add lime to the planting area to compensate; a local garden center or extension service will advise you on the amount to add, which varies depending on soil composition and climate. Dig a planting hole as deep as the root ball and twice as wide. Remove the plant from its container. Set the plant in the hole, making sure it's at the same depth as it was in the container. Backfill around the roots with the amended soil, then water to settle the roots and remove air pockets in the soil.
Spread a 2- to 3-inch layer of organic mulch over the root zone to keep the soil moist and to discourage weeds. Renew the mulch each spring. Fertilize Malva plants in the spring when new growth emerges and again when the first flowers appear. If the garden is in sandy soil, give the plants a third feeding in mid-summer. Always use a fertilizer formulated for flowering garden plants. The amount of fertilizer to apply will depend on the product chosen, so follow the package directions carefully. Too much fertilizer can damage the plant or promote foliage growth at the expense of flowers. Water when the top 2 or 3 inches of the soil feel dry. Apply enough water so that the top 6 to 8 inches of soil are moist. The actual amount to apply depends on the weather and soil structure, but for most gardens 1 to 2 inches of water per week is sufficient. Zebra mallows are not drought resistant, however, so they need extra water during dry spells and windy weather. Remove flowers as they fade to encourage reblooming. Zebra hollyhocks will continue to bloom until fall if regularly deadheaded. Cut the plants back to ground level after the first frost. Remove all debris from the garden to keep insects, rodents and disease spores from overwintering near your plants.
- Zebra mallow can be short-lived, but it self-seeds readily, so once it's planted, plenty of plants will grow every year. The little seedlings are easy to move around and re-establish themselves quickly.
- Malvas are rarely subject to disease, but leaf-chewing insects can be a bother. Japanese beetles, in particular, find them tasty. Light numbers can be washed off with a garden hose or picked off by hand, but an insecticide will be needed to control heavier infestations.