Preparation of the vineyard site is very important since vineyards, once established, are maintained for many years. Correcting site imperfections and improving the site will add greatly to the longevity and productivity of a vineyard. Some activities (ie. land levelling, drainage) can only be done prior to planting. Other activities (liming soil and managing weeds) can take a few years to accomplish. Ideally, a vineyard site should be prepared at least a year or two prior to planting. Activities to prepare the site for planting include soil preparation, drainage, weed reduction, removal of wild hosts, deciding when to plant and determining what to plant.

Soil Preparation

Soil preparation includes adjusting fertility and pH, correcting drainage problems and land leveling. Conduct soil tests a year in advance of planting grape vines, or two years before planting where pH adjustment may be necessary. For vineyards soil samples should be taken at two depths at: 0"-8" and 8"-16" in an 'X' pattern. The samples collected at these two depths should be analyzed separately. Information on soil sampling and a list of accredited labs can be found in the OMAFRA Factsheet, Soil sampling and analysis for managing crop nutrients. For information on nutrition in grapes refer to the OMAFRA website.

If the soil pH is below 5.0, consider applying agricultural limestone to raise the pH to a more desirable level (5.5-6.5). Lime applications should be made the year before planting and the limestone incorporated into the soil as deeply as possible. Fertility adjustments should be made based on the soil tests. OMAF is currently developing nutrient recommendations for our growing conditions.

One year prior to planting the site should be plowed, sub-soiled, land levelled (where necessary) to prepare the site for planting. If restrictive soil layers are present, ripping or subsoiling may be beneficial prior to planting. Trees, shrubs, rocks, and other debris also should be physically removed from the site. If the site has sod, and is on sloping ground where erosion may be an issue, it is best to apply a contact herbicide only to the row area where the vines will be planted (leaving the row middles in sod). The herbicide treated sod can then be sub-soiled, amended with fertilizers and prepared for planting. If the site is on level ground and there are no issues with erosion, the entire site can be plowed and amended with fertilizer and planted to a cover crop, like hybrid sudan, the summer before planting. A small grain cover crop should be planted the fall prior to planting vines.

Drainage

Adequate water drainage is critical in preparation of a vineyard site. Wet soils can reduce vine root growth, and can adversely affect vines that are acclimating to the cold in the autumn. Wet soils are also very susceptible to soil compaction which destroys soil structure and oxygen levels in the soil. Poor soil drainage is indicated by standing water and equipment ruts. Drainage tiles might be needed for proper drainage, and are much easier placed in the ground prior to vineyard planting than after. A list of contractors who can assist with drainage can be found on the OMAFRA website.

Weed reduction/avoidance in the preplant years

Weed management is critical before planting a new vineyard, as weed control is much more difficult after vines have been planted. Control perennial weeds with a two year strategy, targeting the most sensitive growth stage e.g. early bud in thistles. Plant a cover crop to smother weeds, especially in the fall before planting - this will prevent winter annuals from establishing. Use herbicides such as glyphosate to control weeds in the late summer or early autumn before planting.

Removal of wild hosts host species

Prior to planting a vineyard clear out any wild hosts (grape vines etc) that may be hosts or vectors for disease or insect pressure.

Deciding when to plant

In the cool climate regions of Ontario, vines do best when planted as early in the spring as possible (May, prior to budbreak). Delay planting until the soil is not too wet, and when soil temperatures begin to rise. Avoid planting in the fall due to potential issues with frost heaving. Avoid planting in temperatures that approach 30ºC as they can injure the vines and buds.

Ideally, the site should be prepared the previous fall, with only row marking to be completed the year of planting. Communicate with your nursery to ensure that vines arrive early in good condition.

Determining what to plant

It is best to purchase certified grapevines, which have been tested for certain grapevine diseases. This testing does not guarantee disease-free vines, and vines should be visually inspected for visible deformities, insects, or other indications of disease. Most nurseries recommend ordering vines in the fall, for planting in the spring. A list of nurseries that sell grapevines in Ontario can be found at www.grapegrowersofontario.com/node/85. Prior to planting, select cultivars that are desired by your market and cultivars that will mature fruit and wood in your region. Use rootstock and variety combinations that work for your climatic conditions and soil type. A varietal plan is available that will provide useful information on supply and demand of grapes.