The Iowa Gardener: How to grow the regal hollyhock

One of my favorite flowers growing up was hollyhocks. There was a stand of them, along the side of the horse shed on the family farm. My grandmother had planted them long ago, but somehow, magically, they grew back again and again each year, in an assortment of bright pastels on regal, tall stalks that soared above my head.

Hollyhocks (Alcea rosea) are a beloved, old-fashioned cottage garden staple. They come in a couple of different forms, either single (cup-shaped) or double (like pom-pons). They bloom in a variety of colors: blue, pink, purple, red, white, yellow, and even black, for a few weeks, any time starting in June or as late as August.

Best of all, they grow on dramatically tall stalks that range from 4 to 8 feet tall. (Don’t overdo the fertilizer, especially a nitrogen-based type, if you want them to stay strong and more compact.)

Hollyhocks attract birds and butterflies and unlike so many plants, do well even when grown close to a black walnut tree, as long as they get plenty of sun.

They are not fussy about soil, but they don’t like wet spots. And they absolutely need full sun, that is, six or more hours of full, unfiltered light a day.

Hollyhocks, in fact, are easy to grow. All it takes is a little know-how. And if you choose the right type, you can — like my grandmother — have a stand of hollyhocks that brings cheer and beauty year after year — maybe even decade after decade.

Here’s how:

Choose your seed. You often can find hollyhocks already started at the garden center, but they’re so easy to start from seed, it’s a pity not to. Also, seed selection is far better than a selection of established plants, so you can choose just the type of hollyhocks you want.

If you want your hollyhocks to reseed every year, be sure to choose an heirloom cultivar rather than a hybridized type. Read label directions carefully or do a quick check online to figure out what kind it is.

Start seeds indoors or out. Indoors, start seeds no earlier than mid-March. Seedlings can be placed outside in late May. Or you can sow seeds directly in the soil around May 1. Plant the seeds about 1/4 inch deep and about 1 foot apart (thin to about 2 feet apart after the plants have sprouted).

Hollyhocks have long taproots, so if seeds are started indoors, use tall, individual pots and transplant as soon as possible avoid damage.

The trickiest thing about hollyhocks is understanding them. Some are annuals (growing, blooming, and dying all in the same year). But most are biennials, which means they take two years to mature and bloom, and then they die. And just to make things more confusing, some hollyhocks will act like a short-lived perennial and keep blooming for a few years before dying out.

But if you choose the heirloom types that will grow true from seed each year, and allow the flower heads to ripen on the plant, hollyhocks will self-sow and create a stand — like the one by the horse shed — that is a mix of one-year and two-year plants and will bloom beautifully every year.

Hollyhocks also are now available in dwarf cultivars, growing just 30 or so inches high. These hollyhocks behave as annuals, blooming the first year, and sometimes also will behave as a perennial, coming back year after year.

In fall, after frost fells the plants, cut them off to just an inch or two. Don’t pull them out, even if it’s their second year and they’ve bloomed. But do cut back all the hollyhocks to about the ground level. This will prevent fungal disease, including rust, from overwintering.

When rabbit populations are high, they’ll nibble hollyhocks. They don’t seem to bother them, though, when populations are low. If you do have a rabbit problem, plant your hollyhocks in an area enclosed in chicken wire — the only sure way to keep rabbits away from plants. Deer don’t seem to like hollyhocks.

Hollyhocks appreciate regular water, but only on the ground. Their leaves are prone to rust if they stay wet too much (which is why some of the most gorgeous hollyhock stands are in the arid Southwest).

In Iowa, leaf miners can be a problem. They leave distinctive little squiggly lines all over the leaves. Fortunately, though, the damage is almost always merely cosmetic. Pluck off the offending leaves, if they really bother you.

Veronica Lorson Fowler is co-publisher of The Iowa Gardener website at theiowagardener.com.