General description: Interlaken is a seedless table grape cultivar. It’s produces some of the tastiest fruit among seedless varieties grown in Poland. The grapes are greenish-yellow and have a sweet taste. Interlaken is resistant to frost and diseases.

Fruit: Interlaken has grape clusters of medium size. The berries are also medium-sized, round, and greenish yellow in colour. They are very tasty, sweet, and juicy.

Ripening: Interlaken grapes are usually fully ripe by mid-September.

Leaves: This grapevine has medium-sized, five-lobed, green leaves with lightly serrated margins.

Cultivation requirements: This grapevine requires a sunny and warm location. It prefers light, well-drained soil, and doesn’t like heavy, wet substrates. It grows and bears fruit best in slightly acidic soils. It can be cultivated throughout temperate climes, even in areas with a climate unfavourable for other grape varieties. Seedlings should be planted every 1-1.5 meters, 10-15 cm deeper than in the pot they came in. Very small seedlings should be planted in a shallow hole and only covered wholly with soil in autumn. This significantly increases the frost resistance of grapevines and increases the efficiency of watering freshly planted vines.

Care: To build a powerful root system, grapevines need a lot of water. Caring for a newly planted seedling is basically limited to systematic watering. It is especially important to pay attention to watering in early summer and as the grapes ripen. Each young vine requires up to three buckets of water per watering.

Pruning: In the first year after planting, it’s recommended to keep only one to three stems. In the following years, trimming depends on how the vine is to be shaped. Thinning out, in order to obtain high quality fruit, is advised. This shrub grows vigorously and is suitable for forming into the shape of a tall pergola. It thickens fast and may require careful pruning in summer as it produces many fresh shoots in the warmer months. Generally, stems should be pruned to a moderate length and care should be taken whilst selecting which stems and shoots are to be cut, to leave well-fruiting ones on the plant. It is best to leave pruning until late autumn and winter (well before the beginning of vegetation), although, as mentioned, trimming in summer helps control expansion and should be done after new shoots are partially lignified.

Props: This grapevine is perfect for growing on all kinds of fences, pergolas and arbours, trellises and other garden support structures.

Overwintering: Interlaken withstands temperature drops of down to -24°C, however it is recommended to protect the vine for the winter (for e.g., by using agrotextiles). At the beginning of November, cover young seedlings by piling a mound of soil with peat about 30 cm in height over the plants. This not only insulates them from the cold, but also shields them against flooding during the thaw.

Origin: USA.