How to Grow Healthy Grapes

What to Consider Before Planting

The altitude of the location where we want to grow grapevines determines whether it is even feasible in our garden. Growing grapevines freely outside protected positions (south-facing slopes, south-facing house walls) is only possible up to an altitude of 250 m above sea level, otherwise the bushes will freeze in winter and we can expect a harvest on average once every 3 years, in years with milder winters and favorable spring. On the other hand, if we have the opportunity to plant grapevines directly against a building wall that faces south, or southeast or southwest, we can expect a beautiful harvest every year even at 500 m above sea level.

Grapevines require full sun all day; the proximity of taller trees or buildings will always negatively affect the size of the harvest.

Choosing a Variety - Type of Grapevine

The correct choice of variety plays a significant role in terms of resistance to frost and diseases. It should be noted that older and less resistant varieties are still the most commonly sold. Forget about varieties whose names you know from wine bottles in stores. It pays to invest more effort and obtain a quality variety.

Grape varieties are divided into table and wine grapes. The grapes of wine varieties are also tasty, but wine is more difficult to make from table grapes.

From wine grape varieties, for worse soil and climate conditions, we can randomly recommend the variety Hibernal, Medina and the older variety Isabella.

Table grape varieties that are resistant include varieties originating from the territory of the former USSR - Ustojčivyj dokučajevoj, Augustovskyij, Vostorg, Kutuzovskij, as well as modern varieties originating from Czechoslovak territory that are halfway to resistance - Vitra, Pola, Olšava, Ametyst, etc.

From other grape species, we can also recommend Vitis Amurensis, preferably cultivated varieties.

Planting and Pruning Grapevines

With optimal care, grapevines can produce a smaller harvest depending on the variety as early as the second year after planting. For grapevines, as with other fruit plants, to preserve the variety's characteristics, it is necessary to propagate from a part of the plant (cutting), not from seed. We can propagate grapevines ourselves using cuttings, or we can buy grafted seedlings.

We plant the seedling deep, so that the grafting point is several cm above ground level. Grapevines are liana-like plants and require support. In the first year, a stake is sufficient; in subsequent years we build support structures.

Without pruning, grapevines cannot be successfully grown for a longer period.

The basis of pruning all fruit plants is that we cut some parts completely and others only slightly. In simple terms, vine pruning should be deep enough so that next year in autumn the shoots reach the thickness of a pencil. If they are too thick - we pruned too much, if they are weak and not lignified - we pruned too little. The unsurpassed shape that best suits the vine while utilizing its physiological fertility potential is one trunk with one cane or two canes and one renewal spur at the top.

We tie the cane horizontally so that all buds have the same conditions. With vines, the highest positioned part grows most vigorously. This shape, where we have grapes at the same height, we appreciate both during spraying and when applying protective nets. The pictures show the bush before and after pruning. One old cane was replaced with two. Both canes will be tied horizontally again in April.

Green Work

This is the name for work carried out during the growing season. It includes shoot removal, desuckering and shoot shortening. Through these practices we keep the vine bush airy and at a certain size, which helps reduce the possibility of disease attack and makes care easier.

Shoot removal is breaking off shoots early after budding, removing those shoots that do not bear grape clusters and which we will not use for shaping the bush. These would develop unnecessarily at the expense of those bearing grapes.

Suckers we remove similarly as with tomatoes, at least in the area where grape clusters occur. Shoot shortening (tipping) is carried out in July and August, it is necessary to leave shoots sufficiently long, minimum 1 meter, preferably more!

Grapevine Protection

The grapevine is one of the longest cultivated plants on earth, where a large number of varieties have developed thanks to long-term cultivation. Thanks to interstate and intercontinental introduction of vine varieties and species, the global variety assortment has been enriched, however along with new vine species we imported from America the most serious pest and most serious diseases that we must consider when planning grapevine planting.

Phylloxera

At the time of its introduction, it was responsible for the destruction of almost all vineyards in Europe. European vines were not accustomed to this new pest and succumbed to it very easily. Today it is no longer such a threat, as all vineyards are planted on resistant rootstocks that can withstand phylloxera. For home garden conditions, grafted grapevine seedlings are nevertheless recommended.

Downy Mildew Plasmopara viticola

This disease can completely destroy grape clusters and vine leaves. Occurrence is supported by warm and humid weather. At the initial manifestation of the disease, it is characterized by light green, later brown oily spots on the upper side of leaves which are covered with white fungal mycelium on the underside of the leaves. Leaves later dry out and fall off, grape clusters necrotize and dry out.

Chemical Protection Against Grapevine Diseases

Chemical protection products against this disease are divided according to their mode of action into contact and systemic types. Contact preparations are copper oxychloride-based, have shorter effectiveness, with known (minor) side effects.

Systemic preparations have a more complex composition, have longer effectiveness, however their side effects have not been fully researched.

Powdery Mildew – Uncinula necator

The disease manifests as a whitish coating on the leaves, which appear dusted with powdery mildew, hence the synonym Powdery Mildew of Grapevine. White coatings cover the grape clusters, the berry skin hardens and cracks (seed splitting). Sulphur-based preparations are used as contact products against powdery mildew.

Grapevine infection with powdery mildew causes economic damage only if the vine is infected by the end of June.

Grapevine Protection Calendar

The following protection scheme is used for moderately susceptible varieties. For more resistant varieties (see recommended varieties), the first two applications are sufficient, followed only by the last one, applied during grape colouring.

The first treatment of grapevines against downy mildew begins in the pre-flowering period, i.e. in the second half of May or early June. A contact preparation is sufficient for the first treatment.

Further treatment is carried out at 14-day intervals – treatment after flowering. Here it is advisable to treat against powdery mildew as well; both preparations can be mixed in one tank, but direct contact of concentrates must be prevented. It is better to use systemic preparations.

The next treatment should be carried out during cluster closure – when the berries in the clusters begin to touch.

Timing of further applications depends on the weather; if there is a dry period without precipitation, treatment is not necessary. Conversely, if the period is warm and humid, treatment is needed every 14 days in the case of systemic preparations and every 7 days when using contact preparations.

Application Recommendations

It is advisable to use a wetting agent, as the preparation then has better effectiveness. For good effectiveness of systemic preparations, it is necessary to use one type only twice per season, to prevent resistance from developing.