Hardy kiwi is an extraordinarily vigorous woody climber grown for its grape-sized, smooth-skinned fruit, which is eaten whole and tastes like a sweeter kiwi. A mature vine on a strong pergola or fence produces hundreds of fruits in early fall. The small white flowers in late spring are fragrant but not showy, and the heart-shaped leaves are large and handsome.
You need a male and a female plant for fruit (one male pollinates up to eight females), or a self-fertile cultivar such as 'Issai', which crops lighter. Plant in full sun to part shade, in soil that drains, 10 to 15 feet apart, with the structure already built: an established vine weighs hundreds of pounds and flattens an ordinary trellis. It takes three to five years to fruit. Prune hard in late winter, cutting last year's growth back to a few buds, and again in summer to keep it in bounds.
It is hardy to zone 3, but the new growth is caught by late spring frosts, so avoid a frost pocket. Pick the fruit when it softens slightly or when the first ones drop, and ripen the rest indoors; it keeps for weeks in the refrigerator. Cats are drawn to the vine as they are to catnip and can wreck a young plant; protect it until it is woody.
Botrytis (grey mould)
Grey fuzzy mould on petals and stems, worst in cool wet conditions.
Remove affected parts immediately. Improve air circulation. Avoid overhead watering. Apply copper fungicide if severe.
Crown Rot
Lower leaves yellow and wilt; the base of the rosette turns brown and soft, sometimes with white fungal threads at the soil line. Plants collapse in wet conditions.
Remove and destroy affected plants. Improve drainage and avoid overhead watering. Do not mulch directly against the crown. Space plants for airflow and avoid replanting in the same wet spot.
Phytophthora Root Rot
Wilting despite moist soil, yellowing leaves, stunted growth, and dark, decayed roots and crown tissue. Vines may collapse during hot weather.
Plant in well-draining soil and avoid waterlogging. Remove and destroy affected vines. Improve drainage with raised beds or amended soil and avoid overwatering.
Bacterial Blight (Pseudomonas)
Angular dark spots with yellow halos on leaves, wilting shoots, and oozing cankers on canes in spring. Buds may fail to open.
Prune out infected wood in dry weather and disinfect tools between cuts. Avoid overhead watering and excessive nitrogen. Apply copper sprays during dormancy in areas with recurring infection.