How to Make Mustang Grapes Bear Fruit

Prune established mustang grapevines in late winter before they begin their spring growth. Grapevines bear fruit on new wood and bear their best harvests with pruning. Cut away all but four to six lateral canes on the grapevines. Prune each of these cants to five to 12 buds. Each bud produces new shoots for foliage and grape production.

Put a trellis or arbor behind the grapevines if you don't have one. Tie the lateral canes and main vine to the trellis or arbor, and train your remaining lateral canes along the wires of a trellis. The grapevines need full sun and air exposure if they're to grow and produce fruit.

Amend the soil around each grapevine for better drainage and soil conditioning. Grapevines grow and fruit best when they have adequate nutrition and loose soil for deep, healthy root growth. Turn 4 to 5 inches of organic compost into the top layer of soil, and dig as deep as you can without disturbing the roots. Compost also allows water to drain down to the roots more easily.

Fertilize the mustang grapevines to encourage foliage growth, blooming and fruiting. Give each grapevine 1 pound of 10-10-10 fertilizer before new spring growth starts. Mix the fertilizer into the soil around the grapevine with 6 to 12 inches of space between the grapevine and the fertilizer trunk.

Water the grapevines with 2 inches of water after fertilizing, and every week thereafter. Mustang grapevines are hardy to drought but can't produce fruit without adequate moisture. Mulch the soil around the grapevines with 2 inches of organic mulch to maintain moisture and warmth.