Latin Name

Wisteria sinensis 'Kofuji'

Common Name

Miniature Chinese wisteria

Family

Fabaceae, the Pea family.

What kind of plant is it?

Woody vine, although growth is so congested that growth long enough to twine is unusual.  Think of 'Kofuji' as a shrub that only occasionally remembers its vining heritage.

Hardiness

Zones 5 - 9. 

Habit

Dense and shrubby, looking more like a miniature tree than a vine. 

Rate of Growth

Slow.

Size in ten years

A clump two feet wide and tall. 

Texture

Unusually delicate.  Ferny.

Grown for

its extreme dwarfishness and restraint:  Uncontrolled Chinese (or Japanese) wisteria is infamous for rambunctious and far-reaching growth, with profuse whips that, especially if they race along the ground, can lengthen to fifteen or twenty feet in a season.  'Kofuji' is reticent about growing even an inch a year, with twiggy non-vining stems that (usually) don't so much as hint that the plant descends from such an enormous and aggressive species.    

its foliage:  Although the foliage has the same pinnate form as full-size wisteria, whose leaves can be 12 to 16 inches long, those of 'Kofuji' are two inches long at best, with leaflets of barely a half inch.  'Kofuji' is so petite that it could find employment as a stunt-double for the legendarily tiny-leaved elm, Ulmus parviflora 'Hokkaido'.

its natural air of bonsai:  With its tree-like form but Lilliputian foliage and overall size, 'Kofuji' seems to have done most of the work to form a bonsai for you.  If given intensive bonsai training—which typically results in reduced foliage and flower size, not just reduced overall size—would the result be a mini-miniature 'Kofuji' that is only six inches overall, with pinnate leaves a half-inch long, and leaflets barely a sixteenth of an inch?  Oh my, the experiment that needs doing! 

Flowering season

Spring: 'Kofuji' is a shy bloomer, with only occasional inch-long clusters of tiny lavender flowers.

Color combinations

Because flowering is modest, 'Kofuji' is grown for its texture, startlingly diminutive size, and sheer "Who knew?" value.  Its green foliage goes with everything.

Plant partners

'Kofuji' is so tiny that it could easily be swamped by plants that, in any normal garden setting, would themselves be classed as dwarfs.  Best used as the "big guy" amid a planting of other extreme miniatures and mosses.  Underplant with a specimen clump of the tiniest of dwarf hostas, which would look as deliciously monstrous in this context as a gunnera would in a full-sized garden.   

Where to use it in your garden

To my eye, 'Kofuji' is too tiny to be effective in anything other than containers, where it can strut its stuff as the "tree" in a pint-sized landscape.  Wisteria sinensis is so hardy that 'Kofuji' can be included in trough plantings that overwinter without protection in Zone 6 and warmer.

Culture

Full sun, in humus-rich soil that also has decent drainge.

How to handle it

Plant in Spring or Fall.  If planted in-ground, site where surface water drains quickly away; wisterias are not comfortable in ground that is too wet.  The shrub needs little maintenance, other than to keep neighboring vegetation from growing so large that 'Kofuji' is cast into shade.       

How to handle it: Another option—or two!

If planted in a container, keep in mind that 'Kofuji' needs some coolness in Winter, and is quite happy growing in climates where the temperatures fall to below zero.  The container needs to be as cold-tolerant as 'Kofuji' itself.  Good drainage is as essential to container "hardiness" as it is for most plants.  Put even containers that are solidly Winter-hardy up on small blocks or, as long as they, too, are Winter-hardy, on pot-feet:  Containers are more susceptible to Winter damage if their bases rest where water can collect and freeze, even briefly. 

If you're gardening in Zone 5, show a bit of kindness in late Fall and mulch around the container with actual mulch.  If you have multiple containers and they can be grouped together, surround them with hay bales, instead.  The mulch or hay doesn't keep the container (or the plants it contains) warm, per se.  Instead, it slows down the cycle of freezing and thawing that, otherwise, might happen almost daily.  Ideally, mulched plants are kept frozen for extended periods, and take longer to thaw as well as to re-freeze.  This slower cycle more closely imitates the plant's experience when growing in-ground. 

I have a hypertufa container that is currently planted with a dwarf willow.  I'm finding it impossible to keep the container watered enough to make the willow happy.   Better to transplant the willow to a garden bed, and replant the container with something—say, mini-wisteria—that honestly appreciates decent drainage. 

Downsides

'Kofuji' is shy to flower, so don't expect the dramatic display that's typical for wisteria. 

Variants

To my knowledge, there are no other dwarf forms of Wisteria sinensis—or of any other Wisteria species.  No garden is complete without one of the normal-sized cultivars, whose eager and massive flowering will make it the automatic star of Spring.  Diligent control of rampant growth is essential for both heavy bloom as well as appealing form and restrained size.  See the article on Wisteria sinensis 'Rosea' for an introduction to growing full-sized Chinese wisteria.   

Availability

On-line.

Propagation

By cuttings.

Native habitat

Wisteris sinensis is native to China.  If the cultivar name is any indication, 'Kofuji' was first identified in Japan.