Although regional weather conditions ultimately dictate the timing for planting grape vines, optimal planting occurs in late winter, if weather conditions allow, or early spring, if irrigation is available. The possibility for late winter planting exists only if the danger of freezing temperatures has passed. Preparation of your own dormant cuttings for planting presents different factors that determine planting time. Early spring remains the best time to plant cuttings, but the readiness of the cuttings themselves for permanent planting overrides seasonal timing. The appearance of roots or a callus ring on the cutting's base signals its readiness for planting.
Obtaining grape vines for planting can influence the timing of planting. To avoid problems with plant availability and quality when ordering grape vines from the nursery, order them prior to January or February. The best rooted cuttings, often termed the best by the nursery, are the first to go and remaining vines may be of lesser quality -- vines too weak to survive. Ensure that the nursery guarantees shipment of the vines at or near your desired time frame for planting, as grape vines should be planted immediately and preferably not stored.
Storing dormant vines destroys their roots and buds and forestalls the vine from optimal growth, potentially resulting in the plant's death. Circumstances sometimes prevent immediate planting. Vines may require storage if delivery occurs before the site is ready for planting -- soil preparation, irrigation or trellis construction may not be complete, for example. Unpacking the vines, covering their root system with soil and placing them in a cool or shady location until planting is known as "heeling-in." Under proper conditions, vines remain healthy in the heel bed for up to four months. Water the heel bed periodically to maintain moist roots. Allowing the roots to dry out while "heeling" them in results in poor growth or vine death.
Grape vines planted in pots and held indoors during cold weather facilitates year-round grape production if the vine is old enough to bear fruit, given adequate access to sunlight and an ideal placement in a wooden planter to protect the vine's roots from excessive heat or sun damage. One method of pot-growing entails planting a vine in a pot in which the main shoot remains attached to a healthy fruiting cane from a parent vine, resulting in up to five times greater grape production.
When transplanting a potted vine to a permanent outdoor location, seasonal conditions dictate timing. Plant potted vines in the early spring after the risk of frost is over. (See References 1)