Grafting

Why Graft Plum?

Grafting fulfills several important tasks when growing plums:

1. Preserving cultivar traits. Cultivar plums do not reproduce true-to-type from seed — a plant with a random set of traits grows from seed. Grafting ensures that the new tree is an exact genetic copy (clone) of the mother cultivar (Gull et al., 2023; Martin, 2019).

2. Accelerating fruit bearing. Grafted plants come into bearing 2–4 years earlier than those grown from seed. Seedling plums may not produce a crop for 5–8 years or more (Westwood, 1993).

3. Adaptation to conditions. Using a specific rootstock allows you to grow a plum that is resistant to drought, waterlogging, frost, or calcareous soils. This is especially important for gardeners in different climatic zones.

4. Obtaining trees of the desired size. With clonal (vegetatively propagated) rootstocks, you can regulate vigor: producing compact dwarf or semi-dwarf trees that are convenient for care and harvesting.

Rootstock and Scion: Two Partners in One Tree

A grafted plant consists of two parts, each performing its own function:

Rootstock — the root system and lower part of the trunk. It supplies the tree with water and mineral nutrients from the soil, determines resistance to adverse conditions, influences tree size and longevity. As I. V. Michurin figuratively put it, "the rootstock is the foundation of the fruit tree" (Kurennoi et al., 1985).

Scion — the upper, above-ground part (the cultivar). It forms the canopy, leaves, flowers, and fruits. The scion determines the flavor, size, and ripening timing of the fruits, as well as their market quality (Martin, 2019).

The interaction between rootstock and scion is a complex physiological process. Through the root system of the rootstock, water and mineral elements enter the plant, while the scion, in turn, supplies the rootstock with photosynthetic products produced in the leaves. The success of grafting depends on how compatible these two genetically different components are.

Why Cultivar Plums Are Not Grown from Seed

In most fruit crops, including plum, seed propagation for cultivar preservation is not applicable for several reasons (Trunov & Samoshchenkov, 2012):

• Heterozygosity and segregation. Plum is a cross-pollinated plant. When one cultivar is pollinated with pollen from another, the seeds receive mixed heredity. Seedlings grown from such seeds turn out to be heterogeneous and lose the traits of the mother plant (Krivko, 2014).

• Late entry into bearing. Seedlings of most stone fruit crops begin to bear fruit considerably later than grafted plants.

• Large size. Trees of seed origin grow vigorously, making care and harvesting difficult.

An exception is some species propagated apomictically (seed formation without fertilization), but cultivar plums do not belong to them (Krivko, 2014).

Thus, grafting is the only reliable way to obtain a sapling of exactly the cultivar you need, with specified characteristics in terms of vigor, resistance, and fruit quality.

2.1. Seed Rootstocks

Seed rootstocks are grown from seeds. Their main advantages are good adaptability to local conditions, a strong taproot system, longevity, and relative low cost. The main drawback is the heterogeneity (variable quality) of seedlings and, as a rule, strong growth of grafted trees.

The following seed rootstocks are used for plums in different regions:

• Cherry plum (Prunus divaricata Ldb.). This is the primary vigorous rootstock for plum in the southern regions of Russia and the North Caucasus. Cherry plum seedlings are drought-tolerant, undemanding to soils, and well compatible with most cultivar plums. However, on heavy, waterlogged soils, cherry plum may suffer (Kurennoi et al., 1985; Potapov et al., 2000).

• Seedlings of cultivar plums (Prunus domestica). In central Russia and the Volga region, seeds of locally adapted, hardy cultivars (e.g., Antonovka, Skorospelka krasnaya, etc.) are used to obtain rootstocks. They are well compatible with grafted cultivars and ensure a good yield of saplings. The winter hardiness of such rootstocks is satisfactory but lower than that of cherry plum.

• Blackthorn (sloe) (Prunus spinosa L.) and damson plum (Prunus insititia L.). These rootstocks are used in the central gardening zone and in more northern areas. Their winter hardiness is higher than that of plum seedlings, they are undemanding, and they are well compatible with cultivars. Trees on blackthorn grow to medium size and are long-lived (Potapov et al., 2000; Westwood, 1993).

• Ussurian plum (Prunus ussuriensis Kov. et Kost.). Used as a rootstock in Siberia and the Far East due to its high frost resistance. Important: not all European plum cultivars are well compatible with this rootstock, so preference is given to locally zoned cultivars (Kurennoi et al., 1985).

• Sand cherry (Bessey's cherry) — Cerasus besseyi. Used in Siberia as a rootstock for plum. It is distinguished by high winter hardiness and drought tolerance, but compatibility with some cultivars may be limited (Westwood, 1993).

Why it is important to use seeds from verified sources

To obtain high-quality seedlings, seeds are harvested in specialized mother-seed orchards or selected from ecologically adapted local forms. Seeds from other climatic zones may produce rootstocks that are insufficiently winter-hardy or poorly compatible with local cultivars (Trunov & Samoshchenkov, 2012).

2.2. Clonal (Vegetatively Propagated) Rootstocks

Clonal rootstocks are propagated vegetatively (by layering, cuttings, micropropagation). They provide genetically uniform planting material, allow regulating tree vigor, and often possess special properties — resistance to diseases, pests, and soil conditions.

For plums and related crops (cherry plum, peach, apricot), clonal rootstocks from domestic and foreign breeding programs are increasingly being used.

Main clonal rootstocks for plum:

• VVA-1 (VNIISPK — All-Russian Research Institute of Fruit Crop Breeding). A dwarf clonal rootstock obtained from crossing Bessey's cherry and apricot. It reduces the growth of grafted trees by 30–50% compared to seed rootstocks. It is well compatible with all plum and cherry plum cultivars. Winter hardiness is high; the rootstock anchors well in the soil and does not produce suckers. Propagated by green cuttings and layering (satisfactorily) (Potapov et al., 2000; Trunov & Samoshchenkov, 2012).

• Kuban-86 (AP-1). A vigorous clonal rootstock, a hybrid of cherry plum and peach. Well compatible with plum, cherry plum, and peach cultivars. Possesses high root winter hardiness, is resistant to waterlogging, and produces a strong root system. Propagated by green and lignified cuttings (Trunov & Samoshchenkov, 2012).

• Druzhba. A medium-vigor clonal rootstock, a hybrid of Bessey's cherry and apricot. Provides good winter hardiness of trees and abundant fruiting. Used in southern regions (Potapov et al., 2000).

• VSB-1. A dwarf rootstock, similar to VVA-1. Reduces tree growth by more than 50%. Can be used for dense plantings (up to 1200 trees/ha) (Trunov & Samoshchenkov, 2012).

Foreign clonal rootstocks, such as Marianna 2624 (a hybrid of cherry plum and P. munsoniana) and Myrobalan 29C, are also known for their resistance to root-knot nematodes and suitability for heavy, wet soils. However, under Russian conditions, their winter hardiness may be insufficient, so preliminary trials in your region are advisable before widespread use (Westwood, 1993; Gull et al., 2023).

2.3. Compatibility of Rootstock and Scion

Compatibility is the ability of two different plants (rootstock and scion) to form a strong and long-lasting physiological union. Criteria for compatibility:

• Botanical proximity. The best compatibility is achieved when using rootstocks of the same species or closely related species within the genus Prunus. Plum (Prunus domestica) is well compatible with cherry plum (P. divaricata), blackthorn (P. spinosa), damson plum (P. insititia), and some other plum species (P. salicina) provided the cultivar-rootstock combinations are properly selected (Westwood, 1993).

• Specific incompatibility. Some plum cultivars may be poorly compatible with certain rootstock species. For example, cultivars President, Kelsey, Stanley, and Robe de Sergeant are poorly compatible with cherry plum rootstock (P. cerasifera). For such cultivars, other rootstocks are preferable (Hartmann et al., 2011; Westwood, 1993).

• Viral and mycoplasmal incompatibility. In some cases, poor union or death of grafted trees is not due to genetic incompatibility but to the presence of viruses (e.g., Plum pox virus) that disrupt the vascular system at the graft union. The use of certified, virus-tested planting material significantly reduces this risk (Potapov et al., 2000).

2.4. Using Cherry Plum, Blackthorn, and Other Rootstocks: Practical Recommendations

Cherry plum (P. divaricata) — a versatile rootstock for the south and central zone

• Advantages: good compatibility with most cultivars, drought tolerance, undemanding to soils.
• Disadvantages: low winter hardiness of roots (withstand down to –12…–15 °C depending on form), so in regions with severe winters (north of Voronezh Oblast), using cherry plum is risky.

Blackthorn and damson plum — for colder regions

• These rootstocks are more winter-hardy (roots withstand down to –20 °C and lower) and grow well on heavy, wet soils. Compatibility with cultivar plums is usually good, although individual cultivars may show incompatibility (Westwood, 1993).

Ussurian plum — for Siberia and the Far East

• Possesses exceptional frost resistance. However, compatibility with European plum cultivars (P. domestica) is often poor, so mainly local Siberian cultivars and hybrids are grafted onto it.

Sand cherry (Bessey's cherry) — as a dwarfing rootstock

• Can be used to produce compact trees in hobby gardens, but often yields short-lived trees due to poor compatibility and mismatched vigor (Westwood, 1993).

2.5. How to Choose a Rootstock for Your Orchard

1. Assess your region's climate. If winters are cold and snowless, choose frost-hardy rootstocks (blackthorn, Ussurian plum, VVA-1). In warm southern regions, cherry plum and its clonal forms can be used.

2. Determine soil type. On heavy clayey, waterlogged sites, use rootstocks resistant to waterlogging (blackthorn, damson plum, Kuban-86). On light sandy soils, drought-tolerant rootstocks (cherry plum) are preferable.

3. Decide on the desired tree size. If space is limited, choose dwarf clonal rootstocks (VVA-1, VSB-1). For large areas and high yields per tree, vigorous seed rootstocks (cherry plum, cultivar plum) can be used.

4. Consider compatibility with the cultivar. Before ordering a rootstock, confirm that your plum cultivar is well compatible with the chosen rootstock. This is especially important for rare or old cultivars (Westwood, 1993).

5. Purchase rootstocks from trusted suppliers. Use only zoned rootstocks recommended for your region. Pay attention to phytosanitary condition (absence of viruses, galls, damage) (Potapov et al., 2000).

In the next chapter, we will explain how to properly prepare and store scion cuttings for spring grafting so that they remain viable until the time of grafting.

3.1. Selecting Shoots for Cuttings

For scion preparation, one-year-old growth (shoots of the current season) with well-ripened wood is used. The quality of the cuttings directly depends on which tree and from which part of the canopy they are taken.

Basic requirements for source shoots:

• Health. Shoots should be taken from absolutely healthy, high-yielding mother trees, free from viruses, bacterial, and fungal diseases (especially Plum pox virus). It is best to use trees that have been certified and tested (Potapov et al., 2000; Gull et al., 2023).

• Good ripening. The shoot must be fully ripened: wood firm, bark glossy, buds well-formed and large. Unripened (herbaceous) or excessively thin shoots root poorly (Hartmann et al., 2011).

• Sufficient length and thickness. Suitable shoots for cutting are at least 50–60 cm long, about 5–8 mm thick (like a standard pencil). Excessively thick (vigorous) shoots ("water sprouts") often have a large pith and root less well. Too thin shoots produce weak growth (Westwood, 1993).

• Position on the tree. The best cuttings come from the middle part of the canopy, from well-lit outer branches. Apical shoots generally have weaker buds, while lower shoots often produce many flower buds, which is undesirable for scion wood (Trunov & Samoshchenkov, 2012).

• Cultivar characteristics. In stone fruits, including plum, short shoots (less than 40 cm) have predominantly flower buds, so medium-length shoots with more vegetative (growth) buds are used for grafting (Potapov et al., 2000).

3.2. Timing of Scion Collection

The optimal time for collecting cuttings depends on the region and the grafting timing. In most cases, plum cuttings are collected during the plant's dormant period.

Main collection periods:

• Autumn (after leaf fall, but before severe frosts). In southern regions with mild winters, cuttings can be collected in November–December. In the central zone, autumn collection is possible, but cuttings must be immediately placed in storage to prevent freezing (Kurennoi et al., 1985).

• Winter (late December – January). The most common timing in regions with stable snow cover. At this time, shoots are in deep dormancy, and cuttings store well until spring. It is important that there are no severe frosts below –15…–20 °C at the time of collection, as tissues may freeze (Westwood, 1993).

• Early spring (before bud swell). In regions with short winters or when grafting must be done on-site (e.g., in April), cuttings can be collected in early spring as soon as snow melts and buds have not yet started to grow. However, by this time physiological processes have already begun in the cuttings, and they store less well (Hartmann et al., 2011).

Important rule: never collect cuttings during thaws or immediately after severe frosts — tissues may be damaged, and take rates will drop sharply (Trunov & Samoshchenkov, 2012).

3.3. Cutting Technique

Proper cutting technique is the key to good union.

• Use a sharp pruner or grafting knife. Cuts should be clean, without bark tearing.
• The cutting should have 3–4 well-developed buds (for whip grafting — usually 3 buds; for bark grafting — 2–3). Cutting length is usually 25–35 cm (Westwood, 1993).
• The top cut is made 1–1.5 cm above the upper bud, straight or slightly slanted. The bottom cut is made just below the lowest bud (or 1 cm below it) at a 45° angle to facilitate insertion into the rootstock.
• Immediately after cutting, bundle the cuttings (25–50 pieces) and label them with cultivar name, date, and collection location. Attach a tag with the cultivar name to each bundle (Kurennoi et al., 1985).

3.4. Storing Scion Wood Before Grafting

The main goal of storage is to keep the cuttings dormant, preventing premature sprouting, drying out, or mold damage. Optimal conditions: temperature –2 to +2 °C, humidity 85–95 %.

Main storage methods:

• In a cellar or basement. Cuttings are placed vertically or horizontally in boxes, packed in moist sand, sawdust, peat, or moss (the substrate should be moist, not wet). Temperature is maintained at 0…+2 °C. Check periodically for mold (Westwood, 1993; Trunov & Samoshchenkov, 2012).

• In a refrigerator. Small batches of cuttings can be stored in the lower compartment (vegetable drawer) at about 0 °C. Wrap cuttings in a damp cloth or paper, then place in a perforated plastic bag for ventilation. They can keep for up to 2–3 months (Hartmann et al., 2011).

• In snow (snow storage). A very reliable method in regions with stable snow cover. Bundles of cuttings are placed on the ground (e.g., on the north side of buildings), covered with at least 50–60 cm of wet snow, and topped with sawdust or straw to protect from melting. This can keep cuttings until May (Kurennoi et al., 1985; Gull et al., 2023).

• In a trench (heeling-in). If no storage is available, dig a trench about 60–70 cm deep on a dry, non-flooded site. Place bundles vertically or horizontally, cover with moist sand, and top with 20–30 cm of soil. They overwinter well this way (Westwood, 1993).

Important precautions:

• Do not allow drying out. If cuttings lose turgor (become wrinkled), place them in cold water for a day before grafting — this sometimes restores viability (Trunov & Samoshchenkov, 2012).
• Do not store cuttings in warmth — they will break dormancy prematurely and become unsuitable for grafting.
• Watch for rodents — mice and rats can damage bark and buds.

How to check cutting quality before grafting

Before starting work, remove cuttings from storage and inspect:

• Bark should be smooth, without cracks or spots.
• Buds should be firm, not dried out, green when cut.
• On a cross-section, wood should be fresh, whitish-green, without browning (a sign of freezing or drying).

If cuttings are slightly dried out, place them in clean water for 24 hours (with a growth stimulant such as Epin). If they are frozen (brown wood on cut), they are unusable (Westwood, 1993).

In the next chapter, we will cover in detail the best times for grafting plum, the differences between spring, summer, and winter grafting, and how to choose the optimal timing based on your region.

4.1. Spring Grafting

Spring is the main and most reliable period for grafting plum with a scion cutting. At this time, active sap flow begins: the rootstock cambium is actively dividing, bark easily separates from wood, ensuring rapid union.

Optimal timing:

• Early – mid-April (depending on region): when buds on the rootstock have swelled but not yet opened, and scion buds are still dormant. In central Russia, this is usually the second–third decade of April; in the south — late March – early April; in Siberia and the Urals — late April – early May (Kurennoi et al., 1985; Potapov et al., 2000).

• Signal to start work: as soon as air temperature is consistently above +5…+7 °C, and soil has thawed to the depth of a spade. At this time, sap flow has already begun in the roots, and the rootstock has "awakened" (Westwood, 1993).

Advantages of spring grafting:

• High take rate (up to 90–95% with good technique).
• In one season, the scion gives good growth, and by autumn you can have a well-formed sapling or a well-developed branch on a top-worked tree.
• Cuttings stored from autumn are still dormant and tolerate the procedure well.

Peculiarities:

• For spring grafting, scion cuttings must be strictly dormant; remove them from storage immediately before work (or 1–2 days in advance to "acclimate").
• The grafting window is limited: once leaves begin to open actively on the rootstock, cambial activity decreases, and take rates decline.
• For spring grafting, the most common methods are improved whip grafting, cleft grafting, or bark grafting (depending on rootstock thickness).

4.2. Summer Grafting

In summer, budding (shield budding) is performed — using a dormant bud of the current season. This is the primary method for producing saplings in nurseries, but it is also successfully used in hobby gardening for top-working or propagating valuable cultivars.

Optimal timing:

• Second half of July – first half of August (for central zone). Exact timing depends on region: in southern areas — mid-July to late August; in northern areas — late July to mid-August (Potapov et al., 2000; Trunov & Samoshchenkov, 2012).
• Readiness indicator: bark on the rootstock should separate easily from wood ("sap flow" — active cambium). In plum, this period coincides with the second flush of shoot growth.
• Finish budding no later than 1.5–2 months before steady cold weather, so the bud has time to take but not start growing (otherwise, the young shoot will freeze in winter) (Westwood, 1993).

Advantages of summer budding:

• High productivity: only one bud is used per rootstock, allowing economical use of scion material.
• By autumn, the bud has taken but does not sprout (remains dormant until spring), so the sapling does not waste energy on growth and winters well.
• Summer budding allows correcting unsuccessful spring grafts (re-budding) (Kurennoi et al., 1985).

Important nuance: for budding, use fully ripened shoots of the current year with well-formed buds. Remove leaves from such shoots (leaving petioles about 1 cm long), and store shoots in damp cloth or water in a cool, shaded place until grafting.

4.3. Autumn Grafting

In autumn, plum grafting is practiced less frequently, mainly in southern regions with mild climates. In the central zone and further north, autumn grafts are not recommended due to the risk of freezing.

Possible timing:

• Late August – September, when the second flush of shoot growth has ended, but at least 1–1.5 months remain before steady frosts (Westwood, 1993).
• Mainly budding or bark grafting (on scaffold branches) for top-working mature trees when spring grafting for some reason failed.

Risks of autumn grafting:

• Short period for union: if less than a month remains before cold weather, the graft may not take and may freeze out.
• In northern and temperate regions, autumn grafting often leads to scion death due to early frosts.

Recommendation: in most cases, in autumn it is better to limit yourself only to those operations that are guaranteed to finish before cold weather, and give preference to spring and summer timings.

4.4. Winter Grafting (Bench Grafting)

Winter grafting is grafting performed indoors during the winter months, using pre-dug and stored rootstocks (one-year-old seedlings or root segments). The grafted plants are then stored in stratification chambers until spring and planted out in the ground in spring.

Timing:

• From mid-December to the end of March depending on region. In the central zone, grafting is performed from January to March; in southern areas — from December to February (Kurennoi et al., 1985; Trunov & Samoshchenkov, 2012).

Technology:

1. In autumn, dig up rootstocks (seedlings or root segments), cut them to 12–15 cm length, wash, and store in a cellar at 0…+2 °C in moist sand.

2. 5–8 days before grafting, bring rootstocks into a warm room (room temperature) to activate cambium. Bring scion cuttings in 1–2 days before work.

3. Perform grafting (usually improved whip grafting or side grafting). Wrap the union with plastic tape, and sometimes dip the scion in melted paraffin to prevent drying.

4. Place grafted plants in a stratification box with moist sand or sawdust and keep for 2–3 weeks at +18…+22 °C for union, then transfer to a cold cellar (0…+2 °C) until spring planting (Westwood, 1993).

Advantages of winter grafting:

• Time saving in the nursery: by spring, you already have ready grafted plants that can be immediately planted out in the nursery row.
• Possibility to graft at a convenient time, without rushing.
• Good take rate (up to 85–95%) when technology is followed.
• Especially effective in regions with continental climates, where conventional summer budding often suffers from winter losses (Kurennoi et al., 1985).

Where used: mainly in large nurseries, but for farmers with storage facilities, winter grafting can be an excellent solution for producing large batches of saplings.

4.5. How to Choose Timing Based on Region

4.6. General Rules for Any Timing

• Rootstock must be more active than the scion. This means before grafting, the rootstock must have "wakened" and started sap flow, while the scion remains dormant. For spring grafting, cuttings are kept cold until the last moment (Westwood, 1993).
• Weather: graft on a dry, calm, not too hot day (preferably morning or evening). Rainy weather and strong sun reduce take rates.
• Tool cleanliness: knives and pruners must be sharp and disinfected (with alcohol or potassium permanganate solution) for each new cultivar or rootstock to prevent infection transfer (Hartmann et al., 2011).

In the next chapter, we will cover the main grafting methods used for plums — from simple whip grafting to budding — and you will learn which method is suitable for different situations.

5.1. Whip Grafting — Grafting a Scion onto a Rootstock of Equal Thickness

Whip grafting is a method where rootstock and scion have approximately equal thickness (usually 0.7–1.5 cm). This method is most often used in spring, before bud break, when the scion cuttings are still dormant and the rootstock has already "awakened" (Westwood, 1993).

5.2. Cleft Grafting

This method is used when the rootstock is significantly thicker than the scion (e.g., when top-working a mature tree or replacing a cultivar on branches 3–10 cm thick). It is also often used for grafting onto a thick stump or trunk (Kurennoi et al., 1985).

Execution technique:

1. Make a clean cut on the stump or scaffold branch, clean it with a knife.

2. In the center of the stump (or offset to the edge if the stump is not very thick), make a cleft 4–5 cm deep using a knife and a small mallet or a special wedge.

3. Insert a scion cutting (or two cuttings from opposite sides) whose lower part is shaped into a double-sided wedge about 3 cm long. It is important that the cambial layers of scion and rootstock match on at least one side. To do this, offset the scion slightly toward the edge of the cleft (Westwood, 1993).

4. Seal the cleft with grafting wax (to prevent drying) and wrap tightly — either with tape or elastic film.

Peculiarities for plum:

• On stone fruits, it is important to avoid getting grafting wax on the cut surfaces, as this can interfere with union. Apply wax only to the exposed surfaces of the stump end (Hartmann et al., 2011).
• To reduce the risk of incompatibility when top-working mature trees, it is better to use scion cuttings of the same cultivar or well-tested compatible combinations.

Advantages:

• Suitable for thick rootstocks when other methods are not applicable.
• Allows top-working a mature tree to replace it with a more valuable cultivar.

5.3. Bark Grafting

Bark grafting is used when the rootstock is significantly thicker than the scion, but the bark separates easily (i.e., during active sap flow — usually in spring). This method is often used for top-working thick scaffold branches of bearing plum trees (Westwood, 1993).

Execution technique:

1. Make a clean cut on the end of the branch or trunk, clean it.

2. On the rootstock bark, make a longitudinal cut 3–4 cm long, carefully separate the bark from the wood (gently pry with a knife).

3. On the lower part of the scion cutting, make a slanted cut about 3–4 cm long (single-sided wedge). The scion should have 2–3 buds.

4. Insert the slanted cut of the scion under the rootstock bark so that it fits tightly against the wood and the cambium contacts the rootstock cambium.

5. Wrap the graft site tightly, and cover open cuts (stump end) with grafting wax.

Advantages:

• Suitable for thick rootstocks with easily separating bark.
• Take rate is high (up to 85–90%) provided the bark separates easily.

Peculiarities: bark grafting is done only during active sap flow (spring), when bark separates readily from wood. If bark does not separate — bark grafting will not succeed (Hartmann et al., 2011).

5.4. Budding — Grafting a Single Bud (Eye)

Budding (shield budding) is the primary method of plum propagation in nurseries and hobby gardens. Budding is done in summer (usually July–August), using one dormant bud with a small piece of bark and wood (shield). This method economizes scion material (one shoot can provide 8–10 buds) and has a high take rate (Potapov et al., 2000; Trunov & Samoshchenkov, 2012).

Two budding methods:

• T-cut budding (under bark). Make a T-shaped cut in the rootstock bark: transverse (about 1 cm) and longitudinal (about 2–3 cm) at the grafting site (usually 5–10 cm above ground for seedlings or higher for clonal rootstocks). Gently open the bark with a knife, insert the shield with bud, press, and wrap tightly (Gull et al., 2023).

• Patch budding (without lifting bark). This method is used on thin rootstocks or when bark separates poorly. On the rootstock, make a cut of a thin strip of bark and wood the same length as the shield. Then insert the shield, and it is held by the remaining bark fragment. This method is convenient for clonal rootstocks and is more productive (15–20% faster) (Trunov & Samoshchenkov, 2012).

Preparing cuttings for budding:

• 1–3 days before budding, cut fully ripened current-season shoots at least 50 cm long from mother trees. Remove leaves, leaving petioles 5–10 mm long, and store in damp cloth or water in the shade.
• For shields, use buds from the middle part of the shoot, where they are most developed and have good vegetative buds.

Aftercare for budding:

• After 2–3 weeks, check take: for a successful bud, the leaf petiole falls off easily on light touch, the bud is green and alive. For an unsuccessful one, the petiole blackens, dries, and does not fall; the bud darkens and shrivels.
• Remove the wrapping after 1–1.5 months (in autumn). If budding was done in late summer, the wrapping can be left until spring to avoid damaging the bud (Westwood, 1993).
• The following spring, before bud break, make a cut above the bud (remove the upper part of the rootstock) to direct all nutrients to the developing shoot from the grafted bud.

Advantages of budding:

• High economy of scion material.
• Excellent take rate (up to 95–98%).
• Possibility of re-budding in the same season if the first attempt fails.

5.5. Other Methods (Briefly)

For plums, side grafting (where the scion is inserted into a side cut on the trunk or branch without removing the top) is also sometimes used — convenient for grafting onto dwarf rootstocks or for replacing individual branches. However, this method is more complex and requires experience (Hartmann et al., 2011).

Inarching (approach grafting) — fusing two growing branches without detaching them from their mother plants — is practically not used in commercial or hobby gardening due to labor intensity (Kurennoi et al., 1985).

5.6. Which Method to Choose — Quick Reference

All methods require sharp, disinfected tools and tight, but not too tight, wrapping. It is important to remember that in stone fruit crops (plum, cherry, apricot), cambium is more active in summer, so summer budding and spring grafting using scion cuttings give the best results (Westwood, 1993).

In the next chapter, we will discuss how to properly care for grafted plants, how to monitor take, when to remove the wrapping, and how to shape a new shoot for healthy tree development.

6.1. Checking Take

The first thing to do 2–3 weeks after grafting (for budding — after 2–3 weeks; for scion grafting — after 3–4 weeks) is to check whether the scion has taken.

How to determine take:

• For budding (eye): in a live bud, the remaining leaf petiole falls off on light touch, the bud looks fresh and green, the bark on the shield is smooth and unwrinkled. In a failed one, the petiole blackens, dries, and does not fall; the bud darkens and the shield shrivels (Potapov et al., 2000; Trunov & Samoshchenkov, 2012).

• For scion grafting: a successful scion retains a fresh appearance; buds swell and begin to open (for spring grafting). If the cutting dries, wrinkles, or blackens — the graft has failed (Westwood, 1993).

What to do in case of failure:

• If budding failed (bud died), you can perform re-budding on the same rootstock on the opposite side of the stem (slightly above or below the first site) in the same season (while bark separates) (Kurennoi et al., 1985).

• If spring scion grafting failed, you have the option of summer budding on the same rootstock or repeating the attempt next spring (if the rootstock survived).

6.2. Removing the Wrapping

The wrapping material (plastic tape, special rubber, electrical tape) protects the graft site from drying and holds the components together. However, it must not be left too long — it can constrict the stem, cause girdling, and disrupt sap flow.

Timing for removing wrapping:

• For budding (summer): remove wrapping 1–1.5 months after grafting (usually late August – September), once the bud has taken well. If budding was done late, wrapping can be left until spring, but in spring it must be removed before sap flow begins (Hartmann et al., 2011).

• For scion grafting (spring): remove wrapping when active growth from the upper bud of the scion begins — usually 4–6 weeks after grafting. By this time, union has occurred, and the wrapping is no longer needed (Westwood, 1993).

• For winter grafting: remove wrapping before planting the grafted plants in the ground or soon after planting, when the scion starts growing (Trunov & Samoshchenkov, 2012).

How to remove wrapping properly:

• Carefully cut the wrapping material with a sharp knife (without damaging the bark), trying not to shift the scion. If a self-degrading film that breaks down in sunlight was used, it can be left on, but still check for constriction.

6.3. Removing Rootstock Suckers

One of the most important post-grafting operations is controlling suckers that appear on the rootstock below the graft site. These suckers (wild shoots) take up nutrients and water, slow down scion development, and if left unchecked, can completely overwhelm it (Potapov et al., 2000).

Why suckers appear:

The rootstock, especially from seed, has its own dormant buds that, when plant integrity is disturbed (cutting, grafting), awaken and produce shoots. This is a natural plant response to injury (Westwood, 1993).

How to remove suckers:

• Systematically, as they appear. Remove suckers at least once a month during the growing season. They grow most vigorously in the first half of summer.

• Removal methods:
• Hand-breaking — when shoots are still herbaceous (up to 5–10 cm long), they can be easily broken off without damaging the bark. This is the most effective and safe method (Hartmann et al., 2011).
• Cutting with pruners — for larger shoots. Cut them at the base, as close to the trunk as possible, leaving no stubs (otherwise new shoots will grow from them).
• Avoid mechanical damage — when cultivating the soil in the root zone, try not to damage rootstock roots, as this provokes sucker growth.

Special attention: in plum and cherry plum, suckers form very actively. If not removed regularly, the scion will weaken and may die (Trunov & Samoshchenkov, 2012).

6.4. Shaping the New Shoot

After the scion has started growing, it is important to properly shape it into the future tree. Several operations are performed:

1. Removing competitors and extra shoots (for scion grafting)

• All buds on the scion usually sprout, producing several shoots. Leave one, the strongest and most vertical shoot — it will become the trunk extension. Remove the remaining shoots when they reach 5–10 cm in length (pinch or cut them out) (Westwood, 1993).

2. Canopy shaping (for budding and grafting)

• The following spring (after wintering), make a cut to a stub above the grafted bud — remove the upper part of the rootstock, leaving a stub 10–15 cm long, to which the young shoot will later be tied to grow vertically (Kurennoi et al., 1985). The stub is cut off later, when the shoot has strengthened.
• For scion grafting, if the scion was long, it can also be cut back in spring to a height of 50–60 cm above ground to encourage side branching (for canopy shaping).

3. Tying

• Young shoots are often fragile and can break in the wind. Tie them to a stake (or to the left stub) with soft material (twine, tape). Regularly loosen the ties so they do not cut into the bark.

4. Pinching

• When the one-year-old shoot reaches 60–80 cm, to stimulate branching, you can pinch it (remove the tip), leaving 50–60 cm. Do this in June – early July so that side shoots have time to ripen by autumn (Hartmann et al., 2011).

6.5. Watering and Fertilizing

Grafted plants need enhanced nutrition and moisture, as their root system (especially on clonal rootstocks) is still weak while the scion is growing actively.

• Watering: in the first year after grafting and planting, water regularly, especially in dry weather. The soil should be moist to a depth of 30–40 cm. Frequency — about once a week in hot periods (Westwood, 1993).

• Fertilizing: 1–1.5 months after scion growth begins, apply the first feeding with a complete fertilizer (azophoska, nitroammophoska) — 30–40 g per 10 liters of water under the root. In late summer — feed with phosphorus-potassium fertilizers for better wood ripening (Potapov et al., 2000).

• Mulching: it is useful to mulch the root zone with humus, compost, or mown grass to a layer of 5–8 cm — this conserves moisture and suppresses weeds.

6.6. Protection from Diseases and Pests

Young grafts are more vulnerable to diseases and pests than mature trees.

• Most common problems: aphids, leafrollers, fungal diseases (clusterosporiosis, moniliosis). Regularly inspect young shoots and at the first signs of damage, treat with approved insecticides and fungicides (Gull et al., 2023).

• Prevention: in spring, before bud break, it is recommended to spray the tree with 3% Bordeaux mixture or copper sulfate (to prevent fungal infections).

6.7. Winter Protection

In regions with harsh winters, young grafted plants (especially if grafted on a less winter-hardy rootstock) need protection from frost and sunscald.

• Covering: trunks and the graft site can be wrapped with white non-woven fabric (spunbond) or tied with fir branches.
• Hilling: mound soil or humus around the base of the trunk (and the graft site if low) to a height of 15–20 cm before frost sets in.
• Snow retention: in areas with little snow, ensure snow accumulates around young trees.

6.8. What to Do If the Graft Fails

Do not despair — even experienced gardeners have a failure rate of 5–10%. If the scion has died:

• Remove all dried parts, but keep the rootstock.
• Next season, repeat the graft on the same rootstock (if healthy) or use it for other cultivars.
• Analyze the mistakes: perhaps the cuttings were of poor quality, improperly stored, or technique was flawed. Correct them next time.