Grapes are a versatile crop. With their wide variety of cultivars and species, they can produce fruit even in cold climates with short summers. However, if improperly cared for, they will disappoint even in the warmest and sunniest regions. One of the most important measures for creating a healthy, actively fruiting bush is pruning.
One of the most common methods is treatment in the spring immediately after planting. By following simple rules and choosing the right technique, you can avoid overcrowding and other common problems such as pea-like growth and even frost damage.
Why is spring pruning important?
All grape varieties are classified as vigorous and bushy, medium-sized and dwarf, but they all require pruning. Since this plant is a fruiting vine, it needs help to direct its energy toward either foliage production, if the planting is ornamental, or berries, if the goal is a bountiful harvest.
Some modern varieties are created specifically to combine these two characteristics: with lush, decorative foliage, they produce a good harvest; however, these are more of a technical variety with low taste scores.
Pruning is important in any season because it allows you to:
- reduce density, improve illumination;
- get rid of diseased shoots, branches and leaves;
- improve the level and quality of pollination.
Treatment can be carried out not only in spring but also in autumn, but the former option is more common due to its numerous advantages. Firstly, spring treatments can increase yields by 60-80 percent during the current season. This occurs by directing all the plant's energy toward fruit formation, improving sunlight access to the berries, and, importantly, pollinating a higher percentage of flower stalks.
Secondly, during this period, you can shape the bush itself, including its width and height. Excessive growth will prevent a full harvest, but pruning will help even the largest bush to be properly distributed within its designated area.
The third benefit is increased frost resistance. After awakening, grapevines begin to produce fruiting shoots almost immediately, but frosts can occur several times before summer temperatures return. Pruning acts as a hardening off process, making the vine more resilient and robust.
The fourth reason to prune in the spring is the opportunity to remove all parts of the plant damaged by cold weather without harming the bush even with improper pruning. Pruning requires precision: remove as many excess leaves and side shoots as possible, while still leaving the branches and vines that are capable of producing the largest harvest. If mistakes were made during pruning in the fall, the grapevines have time to recover, and the results after wintering may be disappointing. Conversely, recovery occurs over the summer if the errors were not critical.
There's also one significant drawback to spring pruning methods: the risk of completely ruining the vines by pruning too late. When light and temperature reach a certain level, sap begins to flow. After pruning, liquid will leak from all cuts, causing the vine to "cry," as pruning enthusiasts call it. Saving the plant in this case is extremely difficult, and in most cases, it dies within one or two seasons.
Sap flow rarely begins in March and most often occurs in April in most regions of the country. The plant "orients" itself to soil temperature, not air temperature. As soon as it reaches 6 degrees Celsius, the grapes can begin to move sap and nourish the vines.
How to trim correctly
Regardless of the pruning method chosen, whether with or without trunk formation, it's important to follow a few basic rules. All branches should be pruned only on one side and only with sharp pruning shears. This will prevent damage to the rest of the bush. It's important to find an bud on the shoot to determine the direction of the cut; the line should point away from it, not the other way around. It's important to understand the difference between a fruiting shoot and a replacement branch: the former should be positioned higher than the latter.
Selecting branches for removal is easy. First of all, look for any that are frozen, diseased, discolored, have suspicious spots, or are attacked by bugs. Secondly, look for branches that are too thin or too thick. The former will not produce fruit due to excessive foliage growth, while the latter are unlikely to support a sufficiently large cluster. Anything larger than 12 mm and smaller than 4 mm in diameter should be removed.
Standard molding
Standard bushes produce the best yields in southern climates and temperate zones. So-called "pure" standard bushes are suitable for hot, sunny summers lasting 150-170 days, while cordons, which are not raised too high above the ground, are suitable for a shorter growing season.
This type of pruning should begin in the first year of planting. Only two buds, the ones that look the strongest and healthiest, should be left. Over the summer, these will produce and grow two shoots, which should be protected for the winter, as the risk of grapevine mortality is greatest during the first year.
In the second year, the trunk begins to form. The strongest shoot should be pruned back to three buds, the weaker shoot to two. Tie the main shoot to a vertical support, and set the reserve shoot slightly to the side. Later, the support can be moved horizontally to form a proper bush. Pinch off all buds below the branches to leave a clean trunk.
The third year should begin with pinching out all the buds on the trunk, as they will inevitably reappear. Each shoot should have two strong shoots; leave these and prune out the rest. The optimal size is two buds. Only one offshoot should be left on the reserve shoot.
Forming a reserve bush is essential, since in a few years it is these shoots that will allow the bush to be rejuvenated after the entire main trunk has been pruned.
Formless molding
In the first year, it's sufficient to remove only diseased branches and young shoots. Spring-pruned vines must be prepared for winter in the fall: in warm climates, cover the base with soil; in cold climates, cover it completely.
Next year, you can leave 2 to 6 shoots, depending on the number of strong and developed branches. It's also important to consider the space allocated to the specific bush, as each shoot will form a fruiting branch. Prune the vine to 4 buds, culling 2 of them, and train the remaining two to produce strong, clean shoots.
In the third and subsequent years, the main goal is to select fertile branches of optimal length. Two buds should be left on the vine. Then, two shoots should be formed, each of which is tied vertically. This creates branching. Work is always carried out on the lowest formations. This principle is then used in cultivation, since after four years, the vine is considered fully formed. Rejuvenation will be required after six to eight years.
Arched pruning
Arched grapes not only look unique, they also take up minimal space and can be planted above functional areas. Proper pruning and proper care allow you to harvest even more fruit from such an arch than from a flat trellis.
Arched bushes are standard bushes, so pruning in the first few years is similar to that already described. However, only one shoot should be left until it reaches its support, such as a wire, at the desired height. Regular renewal of the arch without excessive growth is achieved by replacing the vines. This can only be done in the fall, so for this type of bush, spring pruning is more of a supplementary process. When pruning before the growing season, the main goal is to form up to six branches. These are the optimal sizes for arches.
Arched bushes thrive in any climate except extremely cold ones, where complete winter cover is required.
Emergency pruning: how to tidy up your bush
It's not always possible to prune vines in time in the spring. New owners often have to tidy up vines that weren't pruned correctly before. Furthermore, treatment can prevent grapevine diseases and impact the final harvest, even if problems are already evident.
Neglected vines don't always fail to produce fruit; they often bear fruit even in this state. However, this doesn't mean they don't require care. Grapes that produce any amount are pruned annually. Treatment of fruiting vines should primarily consist of removing excess buds in the spring; the optimal number is 2 to 4. In addition, it's necessary to regularly prune out all infected vines and any that didn't survive the winter well. Don't leave them behind in the hopes of reviving next season. This will only reduce the yield.
Damaged vines should also be pruned only when dormant, to avoid further injury. You can determine whether a vine has already died and will no longer produce fruit by making control cuts at three points at equal distances. If the cut is dry and light, the shoot can be removed. Pay particular attention to pruning the youngest shoots, as they drain the sap and strength from the entire vine, which will be needed to repair any existing damage. Leaving vines unpruned if there are any "injuries" present will only worsen the vine's condition.
Cold Test: Pruning Frozen Shrubs
Even well-protected grapes can be damaged by severe frosts. This is especially common in winters when the snow cover is thin and the soil lacks sufficient natural protection. The buds and buds bear the brunt of the damage.
Grapes have one not-so-pleasant characteristic for their owners: actively fruiting vines and shoots are afraid of the cold, while replacement, reserve ones often survive even the harshest winters.
Frozen vines
Avoid extensive pruning and pinching of frozen grapevines. A bountiful harvest cannot be expected in such a year; it's important to preserve the plant itself. First, it's important to determine which vines are still alive, and second, which buds are still viable. To do this, make control cuts to check the color of the internal structure and whether sap is flowing through these branches. Spring pruning should be performed after assessing the extent of losses.
If less than 60 percent of buds are damaged and the remaining buds survive, the treatment should be standardized. However, the dead parts should be removed, and then pruning should be planned based on the resulting shape. If frost has killed more than 80 percent of the buds, annual vines have been damaged, and changes have begun in the bark of the main trunk, two treatment stages should be planned. All new shoots are pruned, and strong, vigorous vines are pruned short to further develop the branches, leaving just 2-4 buds. After this, after a few weeks, the remaining green shoots are cut out. Completely dead branches can be left on the support until fall; it is not necessary to remove them in the spring, especially if this could damage the living green parts.
Some plant owners use root restoration techniques when the above-ground portion of the tree freezes completely. The living portion is dug out of the ground to a depth of approximately 30 centimeters, then waited for shoots to emerge, and pruning is performed only the following year using one of the standard methods.
Frozen roots
Root freezing is dangerous. If more than 70 percent of the roots are lost, there's no point in trying to restore the vine; it's best to uproot it and plant a new one. To actively restore the grapevine, it's important to feed the root system with nitrogen fertilizers in the spring.
To improve the health of living roots, water generously with warm water between 40 and 50 degrees Celsius. In spring, cover the ground beneath the bush with black geotextile to help warm the soil.
Determining the condition of the roots is very simple: dig a hole half a meter from the main shoot, preferably at several points. If the roots are brown or black, they are not viable. If they are white, they are not damaged.
Unexpected frosts
Frosts in May and even June, along with sudden cold snaps at night, are not uncommon even in southern regions. If grapes are damaged, don't immediately prune the shoots completely. You can trim them back by two-thirds to allow new ones to develop. This won't significantly affect the yield, but it will save valuable varieties and young vines.
If the main branches and vines have been severely damaged as a result of unexpected temperature changes, they should not be removed completely at once; however, it is necessary to limit the pruning of reserve branches.
Grapes after hail
Hail can cause serious damage to vineyards at any time of year. Before pruning, it's best to treat the vines with antifungal agents. This should be done even if the first berries have already begun to appear. Vines and shoots are pruned using the same principles as for sudden spring frosts. The most damaged and weakest branches are removed, while the remaining ones are shortened to allow for possible recovery.
What to do after pruning
Proper care after pruning can further increase the yield or even correct any pruning errors. Cuts should be immediately treated with a paste. This is useful both when sap is actively flowing, to stop the process, and to prevent fungal infections. Signs of powdery mildew may appear immediately after pruning, especially on bushes without resistance to the disease. Treatment with milk can be helpful: dilute it 1:10 with lukewarm water.
To ensure the bushes "open up," develop vigorously after pruning, and generally enter the growth stage as early as possible, it's essential to provide fertilizer. Ammonium sulfate and superphosphates are suitable for this purpose.
Simply watering the soil is ineffective for grapes. Fertilizers should be applied to a depth of 30-40 centimeters.
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Reviews
Vitaly: Over the past seven years, I've completely switched to the arched method of growing grapes and am very happy with it. I've even created a path in my garden and even a recreation and play area for children. I love how the bunches literally hang down, separate from the leaves, making harvesting much easier. The yield is also amazing. Every year I water the grapes with an ash solution immediately after pruning, and the plants have never had any diseases.
Yuri: We plant grapes in our Amur region. We always choose frost-resistant varieties and train them into standard trunks; these survive the winter better here. In recent years, we've always covered them with two layers of geotextile, and we've never had any frost damage. If the grapes are slow to wake up, I water them with warm water and start pruning them right away, before the sap starts to flow.
Pruning grapes is a must in any climate and for any variety. This heat-loving plant requires maximum light and excellent soil ventilation, which can only be achieved by eliminating overcrowding. Spring pruning is an alternative to fall pruning, especially if the plant faces a difficult and long winter.
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