Jostaberry
Ribes x culverwellii
Family: Grossulariaceae
What it is like
Ribes x culverwellii is a deciduous Shrub growing to 1.8 m (6ft). See above for USDA hardiness. It is hardy to UK zone 6. It is in leaf from April to October, in flower from April to May, and the seeds ripen from August to September. The species is hermaphrodite (has both male and female organs) and is pollinated by Bees. The plant is self-fertile. Suitable for: light (sandy), medium (loamy) and heavy (clay) soils and prefers well-drained soil. Suitable pH: mildly acid, neutral and basic (mildly alkaline) soils. It can grow in semi-shade (light woodland) or no shade. It prefers moist soil.
Height (m): 1.8
Where it is found
Not known in the wild.
A range of garden hybrids.
Conservation Status:
Countries/locations it is found in
How it is used
Food
Rating: 5
Fruit - raw or cooked in pies, jams etc. Intermediate in size and flavour between gooseberries and blackcurrants, tasting more like a gooseberry when under-ripe and more like a blackcurrant when fully ripe. The fruit is rich in vitamin C.
Medicine
Rating: 0
Vitamin C: Plants good for their vitamin C content
Other
Rating: 0
Food Forest: Plants for Edible Forest Gardens and Food Forests.
How it is grown
Easily grown in a moisture retentive but well-drained loamy soil of at least moderate quality. Best grown on a deep sandy loam. Dislikes very heavy clay, chalky soils and thin dry soils, but it can succeed on most soil types if plenty of organic matter is incorporated. Quite tolerant of shade though not fruiting so well in such a position. A group of cultivars of hybrid origin, basically a cross between blackcurrants and gooseberries. Very vigorous plants, producing prolific crops of fruit. They are being grown increasingly in gardens. In general they resist American gooseberry mildew, blackcurrant leaf spot and gall mite. Plants in this genus are notably susceptible to honey fungus. For polyculture design as well as the above-ground architecture (form - tree, shrub etc. and size shown above) information on the habit and root pattern is also useful and given here if available. The plant growth habit is multistemmed with multiple stems from the crown. The root pattern is suckering with new plants from underground runners away from the plant.
Propagating it: Seed - best sown as soon as it is ripe in the autumn in a cold frame. Stored seed requires 3 months cold stratification at between 0 and 5°c and should be sown as early in the year as possible. Under normal storage conditions the seed can remain viable for 17 years or more. Prick out the seedlings into individual pots when they are large enough to handle and grow them on in a cold frame for their first winter, planting them out in late spring of the following year. This plant is a cultivar and will not breed true from seed. Cuttings of half-ripe wood, 10 - 15cm with a heel, July/August in a frame. Cuttings of mature wood of the current year's growth, preferably with a heel of the previous year's growth, November to February in a cold frame or sheltered bed outdoors.
Best place to grow: Woodland Garden Sunny Edge; Dappled Shade;
Habit: Shrub
Hardiness: 5-9
Growth:
Soil: Light (sandy), medium, heavy (clay)
Shade: Semi-shade, no shade
Moisture: Moist