|I have planted some semi-dwarf grapes in my backyard, at what height do I begin trailing the vine? And How|
|Pinot Meunier is the only semi-dwarf grapevine that I'm aware of. You can begin training laterals when the stem reaches 20-24" from the ground. A second set of laterals can be trained at 30" above ground level. Typically grapevines are staked upright and all buds that develop along the main stem are rubbed out until the stem reaches the correct height (in this case, 20-24") and the first laterals to develop at this height are trained on a support wire. You can follow the same procedure until the stem reaches 30". At this point, train the next two laterals and pinch out the growing tip so the plant focuses its energy on extending the laterals.
Best wishes with your grapevines!