Q: When are Interlaken grapes ready to harvest?
A: 'Interlaken' is a very early ripening variety. The grapes are typically ready for harvest in mid-to-late summer, usually from late August into September, depending on your local climate . They ripen 2-3 weeks before the classic Concord grape .

Q: How cold hardy is this grape? Is it suitable for a short growing season?
A: Yes, it is well-regarded for its suitability in cooler climates with shorter growing seasons . It is generally considered hardy in USDA zones 5 through 9 . However, some sources note that while vigorous, its winter hardiness is moderate, and it may be less hardy than varieties like Himrod or Concord in extremely cold regions (below -10°F) . Good site selection and winter protection can help in marginal areas.

Q: How should I prune an Interlaken grape vine?
A: Prune during dormancy (December-March) . 'Interlaken' is best pruned using a cane pruning method . Select two healthy canes on each side of the trunk, prune off up to 90% of the previous year's growth, and shorten the retained fruiting canes to about 7-10 buds per cane . This technique ensures good fruit production.

Q: What are its main disease concerns?
A: While a vigorous grower, 'Interlaken' can be susceptible to common grape diseases. It is reported to have high susceptibility to black rot and powdery mildew, with moderate susceptibility to botrytis . Good air circulation, proper pruning, and planting in full sun are crucial preventative measures.