Why Rootstock Matters
The rootstock influences:
- Phylloxera resistance — the primary reason for grafting
- Vigour — how vigorously the vine grows
- Drought tolerance — some rootstocks access deeper water
- Soil adaptation — tolerance for limestone, clay, or sandy soils
- Ripening timing — rootstock can advance or delay grape maturity
Common Rootstock Varieties
- SO4 — widely used; tolerates wet soils, moderate vigour
- 110R — drought-resistant; popular in Mediterranean climates
- 3309C — low vigour; forces concentration; excellent for premium wines
- 101-14 — moderate vigour; good for fertile soils
- Riparia Gloire — very low vigour; ideal for high-density plantings
The Grafting Process
A bud or scion from the desired grape variety is joined to the rootstock. The graft union heals over weeks, creating a single plant with American roots and European fruiting wood. This is how virtually every vineyard in the world is established.
Ungrafted Vines
A few regions have never been affected by phylloxera — notably Chile, parts of Australia, and some sandy-soil vineyards. These pre-phylloxera, own-rooted vines are prized for their longevity and unique character.