Home grown grapes can range from nearly impossible to succeed with to a low care consistent producer depending on the variety selected. Our soil, climate, pests, and diseases will lead to likely failure with European grape varieties. But there are natives and hybrids that thrive here.
Providing a trellis and proper pruning are two requirements for success with grapes. A high trellis with fruit bearing arms on a horizontal wire at a height of six feet provides sunshine and air flow to keep leaves dryer and more disease free. Pruning to prevent overcrowded growth – known as canopy management to grape growers – also allows leaves to dry faster after dew or rain.
Commercial grapes are most commonly grown in areas with significantly lower humidity than the Chattanooga area. And typically they use fungicides. Organic growers have fungicide options including sulfur, copper, and neem. I grow several varieties of grapes without any organic or stronger fungicides. The following varieties have excellent disease resistance and can succeed without spraying: Cayuga (white), America (purple), Norton (deep purple) and any Muscadine variety.
Muscadines require an especially sturdy trellis as a single vine can produce up to 100 pounds of fruit. Many muscadine varieties require cross pollination to set fruit, but some are self-pollinating. Dark varieties of all grapes are attractive to birds so netting is needed to protect the fruits.
The varieties I listed above are all seeded grapes. Resistance to anthracnose would be required to grow any grape without spraying.
The most troublesome pest in Tennessee vineyards is the grape vine borer. Larvae eat the roots and adults emerge for a very short lifespan very close to grape harvest time. But their life cycle can be interrupted with a plastic mulch. A layer of plastic 2 feet in diameter around the trunk that is in place from late May until the end of August prevents the emergence of these pests.
I’ve got two more backyard fruit posts coming: one on the easiest fruits, and one on the quickest to bear.