Grapevine

Grapevines planted in the ground are largely hardy, but need protection at the sensitive graft union: in late autumn, mound soil around the lower trunk and cover it with a layer of leaves, straw or brushwood; give young vines and container plants extra protection (wrap the trunk or pot in hessian, and place containers against the house wall on an insulating base). Stop nitrogen feeding from midsummer and prune only in late winter (February/March, after the hardest frosts); if late frost threatens, protect young buds with horticultural fleece.

The most reliable method in the home garden is propagation by cuttings with ripened wood (hardwood cuttings). In late summer to early autumn (end of August to early October), or alternatively in late winter, cut one-year-old, well-ripened shoots about 20 to 25 cm long with four to five buds. Make the cut at an angle just below a bud. Remove all leaves except the top one or two. Overwinter the cuttings cool and frost-free in moist sand or seed compost, protected from drying out. In early spring, as soon as the buds swell and before the sap rises, you can soak the cuttings in water for a few days and then plant them so that two buds stay above ground. By autumn they are usually rooted well enough for their outdoor position.

The layering method is particularly suitable if you only need one or two new vines and a strong, flexible cane is available. For this, choose a healthy, long cane close to the ground in early summer, gently pull it down to the soil and bury the middle section in a groove about 10 cm deep. At least two buds must lie underground, with the shoot tip sticking out. Keep the spot evenly moist. After rooting in autumn, separate the layer from the mother plant and transplant it to its final position.

Grafting is the standard in viticulture and is required by law in German wine-growing regions, since because of phylloxera only vines grafted onto phylloxera-resistant rootstocks may be planted there. For a home garden outside designated wine-growing regions, grafting is not essential, but it is recommended if you want to keep a particular table grape or wine variety absolutely true to type and robust. The common omega cut joins scion and rootstock with a positive fit; grafting takes place in winter or early spring, before the sap rises. Without hands-on experience this method is demanding. Cuttings or layering suit beginners better.

Note on sowing: Propagation by seed is not suitable for varieties, since the grapevine is highly heterozygous and the seedlings segregate genetically; the variety's characteristics are lost. Sowing is therefore used only in breeding.