Glade Mallow

This big, easily cultivated perennial has big bold foliage that's valuable for adding structure to a planting. The basal leaves are up to...Read More 18" long and wide, held on long petioles. Few perennials hardy in Z6a where I garden have such showy bold tropical-esque leaves, and of those most are bog plants. Out of bloom, it looks a bit like a ligularia. This makes a great change from the ubiquitous hostas, where the soil is moist.

It likes consistently moist soil but is less demanding of moisture than the usual cast of characters: Rodgersia, Rheum palmatum, Petasites, Darmera peltata, etc.

I agree that the flowers are not especially ornamental. The flowering stems can be cut out as they appear, leaving the more ornamental basal foliage.

This is a monster plant that can quickly reach 10' tall and 4' across under ideal conditions. It grows from a hollow, occasionally branched taproot over a foot deep. It also increases slowly by short rhizomes to form a multistemmed clump, but is not aggressive. Well-established multi-crowned plants several years old can be divided or transplanted with care in early spring before they develop significant topgrowth. I wouldn't try transplanting or dividing at any other time of year. At planting, plants should be spaced not much closer than 4'.

It is reportedly hardy enough to survive the winter in containers in Z5.

Needs protection from wind. Even the basal foliage will show season-long damage from exposure to wind.

Tolerates a good deal of shade, and prefers light shade to full sun, unless the soil is consistently moist. In hot sun, the leaves will flag at mid-day and recover in the evening, like a ligularia.

Easy to grow from seed. Needs at least one moist cold dormancy to germinate. If you want to harvest seeds, you need at least one male plant and one female.

An uncommon endemic of the midwest, in nature it grows on riverbanks, in ditches and riverbottom prairies, openings in floodplain forests, and similar moist soil locations. It's considered a facultative wetland plant. It is rare or endangered over most of its range. According to BONAP, it's native to MN, IA, WI, IL, IN, and OH. It's thought to be adventive elsewhere.

This is a plant that I think should be used more, especially by those gardeners looking for a 'tropical' effect. Yes, it's a Midwest nat...Read Moreive, but the large leaves and lush growth of the plant make it seem more like something from the Amazon.

The description above lists the height at six feet, but this refers to the flower stalks. My plant is quite mature, I've had it for 13 years, and it gets four feet tall by four to five feet wide. The tiny little white mallow flowers are at the tops of tall stems; I usually remove the flowering stem when it appears as the flowers aren't particularly attractive and I see no point in having the plant expend energy on unwanted flowers.

I strongly disagree with the part about keeping this plant constantly moist. Mine grows in a standard garden setting and gets only rainfall for water, which during a Michigan summer often means little or none in August. My glade mallow never shows signs of wilting even when it gets dry.

Glade mallow makes a large taproot and so should be planted in its final spot. If you're not sure where you want it, leave the plant in its pot and move it around rather than planting it and then moving it. Also, because of that taproot resist any requests to divide what appears to be a clump. All the growth is coming off that large root and so you will must likely end up killing the whole plant. If you want more, let your plant set seeds and raise up the seedlings.

I cultivate this species from seeds. Plants are full frost hardy in Poland (zone 6). My plants grow in light shade on sandy soil.

Planted it several years ago, but lost the tag. Plant was idenified this year for me by Ken Robertson of the Illinois Natural HIstory Soc...Read Moreiety at the University of IL. It's growing well in full sun, gravely soil (old driveway), but I do water it.

Napaea dioica is dioecious (male and female plants), diploid. It was introduced by John Clayton in his Flora Virginica and taken up by Karl von Linne (Linnaeus) in his Species Plantarum. As the starting point for nomenclatural priority is the Species Plantarum, authorship is conventionally ascribed to Linnaeus.

It's found in the wild in WI, IL, VA, VT, and parts of PA. It is on the endangered list in Minnesota.