News and Announcements!

Rick Dunst, Viticulturist, Double A Vineyards, Inc.

Winter injury caused by low winter temperatures is an important limiting factor to grape production in many regions the United States. Our Grapevine Characteristics Chart lists grape varieties by their winter hardiness according to USDA hardiness zone. Hardiness is determined by using a number of sources, including university publications, variety release bulletins, and our own and other grower’s experiences.

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Rick Dunst, Viticulturist, Double A Vineyards, Inc.

There are many factors that influence whether or not a specific grape selection will survive and be capable of producing high quality fruit at a certain location, including winter hardiness, length of growing season, and risk of spring frost. A common measure of the growing season is Growing Degree Days (GDD). Grapevine development during the growing season is strongly influenced by air temperature, with little plant development occurring below 50°F. GDD estimates the heat accumulation of the growing season. GDD are calculated by subtracting 50 from the average daily temperature; if that value is less than 0, then the GDD accumulation for that day is zero (there are no negative GDD values). The average daily temperature can be calculated as the daily high temperature plus the daily low temperature divided by 2, so

Daily GDD = (high + low)/2 – 50 Read More »

Rick Dunst, Viticulturist, Double A Vineyards, Inc.

Selecting the proper rootstock for your vineyard is just as important as variety selection. Rootstocks are used to induce or reduce scion vigor or to overcome specific soil limitations caused by physical factors such as soil pH and high salt content, or biological factors such as phylloxera, nematodes, and cotton root rot. While some cultivars are commonly grown successfully on their own roots, others require the use of a specific rootstock for optimal vineyard production.

Traditionally, grapevines were grown on their own roots and, where practical, this is still a common practice. Native American varieties such as ‘Concord’ are tolerant (but not completely resistant) to root feeding by phylloxera, and with few exceptions, the ‘Concord’ industry in the Great Lakes region is comprised of thousands of acres of own-rooted vines. The main advantage of growing own-rooted vines is that vines can be renewed from new growth from buds that push at or below ground level if the trunk system is injured or killed by winter or mechanical damage. They are also easier to produce in the nursery, so initial vineyard establishment costs are lower for own-rooted vines than for grafted vines. Read More »

Shipping Update

We are now accepting online orders to be shipped the Spring of 2015!! 

(Books, Accessories, Chemicals, and Chemical Application Accessories will be sent out on a year round basis). 

Any chemical orders placed between now and the end of February will be held for Spring delivery as we do not inventory these products through the winter months.


Warranty/Return Policy:

Warranty:Warranty applicable only to rooted vines and plants. We are not liable for crop loss or damage from causes beyond our control. We will gladly replace any stock which proves to be untrue to variety or fails to grow the year that it is planted. We are not responsible for losses sustained over the winter. Under no circumstances is our liability greater than the cost of the stock purchased. It is mutually agreed that this is the total extent of our liability involving any matter concerning our product. All claims must be submitted by August, 15th of the year the product is delivered. For losses in excess of 10% we require notice within 30 days of planting so we can verify practices. Only applicable to vines planted by June 1st.


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