Farm Horizons, June 2013
Plant some edibles in your landscaping: gooseberries and currants
By Christine Schlueter
With edible landscaping becoming more popular, it’s time to get acquainted with the gooseberries and currants.
The University of Minnesota has the following tips for you on growing, planting and harvesting them.
Currants and gooseberries are highly tolerant of less-than-perfect sites. Although full sun will result in the healthiest, most productive planting, the shrubs can perform quite well on as little as half-day sun. A soil pH of 5.5 to 7 (moderately acidic to neutral) is optimal, but growth is fine in alkaline soils as well.
Because named cultivars have root systems that are fibrous and shallow, they do not tolerate dry sites without supplemental water. Keep in mind that trees not only cast shade, but compete for water and nutrients as well; a planting location beyond the canopy of shade trees is preferable.
Because currants and gooseberries bloom very early in spring, their flowers are susceptible to late-season freezes. North-facing slopes and sites that experience winter shade would both work well.
If possible, prepare your planting site the fall before you actually plant. Because currants and gooseberries do not perform well under dry or waterlogged conditions, most soils will benefit from the addition of organic material such as shredded peat or compost before planting.
Rid the proposed planting site of all perennial weeds as they are much more difficult to control after planting. Test your soil for pH and nutrient needs; professional soil testing may be done through your county extension office.
Plants ordered from mail-order sources are usually sent bare-root, while those purchased from a local nursery may either be bare-root or potted. Set out either bare-root or potted plants in spring as soon as the soil can be worked; do not be afraid to plant early in the season, as even a plant that is beginning to leaf out can tolerate temperatures as cold as 19 degrees Fahrenheit.
When handling bare-root plants, make certain to keep the plants cool and moist until they go into the ground; the delicate root systems must not be allowed to dry or become waterlogged. Just before planting, soak the roots of bare-root plants in a bucket of clean water for three to four hours.
Currants and gooseberries should be planted at least an inch deeper than they were in the nursery, in holes deeper and wider than their root systems. If lower canes are covered with soil to a depth of two to three buds, this will encourage a larger root system and the development of numerous renewal canes, a strategy that will maximize the useful lifespan of the plant.
Plants may be spaced as close as three feet apart for a hedge-type system in rows at least six feet apart. Black currants are more vigorous and should be spaced four to five feet apart in rows at least eight feet apart. Currants and gooseberries are self-fertile, but research suggests that planting more than one cultivar results in better yields.
After planting, prune all canes back to four to six above-ground buds; the resulting low bud count encourages the development of vigorous new canes.
At planting time you should also provide two to four inches of an organic mulch such as wood chips, pine needles, or compost. Mulching cools the soil, conserves water and suppresses weeds, actions that are preferable in a partially shaded site and essential in a sunny spot.
Beginning the year after planting, renew mulch annually. If you use a low-nitrogen mulch such as wood chips or sawdust, you may need to apply extra nitrogen at fertilization. Signs of nitrogen deficiency include yellowing leaves (older leaves yellow first) and poor growth.You can fertilize yearly with a balanced fertilizer such as 10-10-10 or compost.
You should prune established currant and gooseberry shrubs to encourage vigor and fruit production, improve sun penetration into the bush, and maintain good air circulation to minimize disease.
During the first three years of growth, allow four or five canes to develop per year, removing only weak or damaged wood. Beginning in the fourth year, prune out the oldest wood annually in early spring before growth begins. In addition, remove any weak new growth. A mature bush should have 9 to 12 canes once pruning is completed. Fruit is produced on one-, two-, and three-year-old wood.
The easiest way to tell if the berries are ripe is by tasting, they should be on the sweeter side. When using the fruit for jam, you should harvest it before it is fully ripe so that natural fruit pectin levels will be higher.
Cool picked fruit quickly, placing it in covered containers or closed bags to maintain humidity levels and prevent drying when storing fruit in a frost-free refrigerator. Promptly cooled berries will keep in the refrigerator for up to several weeks.