cutting

Cutting (Vegetative Propagation by Cuttings)
A cutting is a part of a stem, leaf, or root that is separated from the parent plant and placed under suitable conditions in order to produce roots.
Cuttings are classified into different types and are generally divided into three main groups: root cuttings, stem cuttings, and leaf cuttings. Below, several important methods are explained.
A) Root Cuttings
Plants such as silk tree (Albizia) and tuberous begonia can be propagated using this method. Root cuttings are planted either horizontally or vertically in the growing medium. In the case of vertical planting, care must be taken to ensure that the end of the root that was closer to the crown of the parent plant is placed upward.
B) Stem Cuttings
This method is more common than other types. In this method, a part of the stem that has a lateral or terminal bud is separated from the parent plant and placed in a suitable environment for root formation.
After roots are produced, the cutting is planted independently. The stem selected for preparing cuttings may be one of the following three types: hardwood, semi-hardwood, or herbaceous. Accordingly, stem cuttings are divided into three groups.
In hardwood cuttings, the cutting is taken from the woody part of the parent plant’s stem, meaning a section that has fully matured. In semi-hardwood cuttings, the cutting is taken from a partially woody section. Herbaceous cuttings are taken from the youngest part of the stem. In bud cuttings, only the buds present on the stem are used.
Hardwood cuttings are further divided into three types based on how much old wood they contain:
Simple hardwood cutting
This type is prepared from a one-year-old shoot and contains no wood from the previous year.
Heel cutting
In this type, a small piece of two-year-old wood remains attached to the one-year-old shoot.
Mallet cutting
In this type, several centimeters of two-year-old wood remain attached to the one-year-old shoot; therefore, it contains more old wood than a heel cutting.
C) Bud Cuttings
If there is not enough stem material to prepare regular stem cuttings—which usually contain several buds—it is possible to prepare several cuttings from a single stem, each containing only one bud. To do this, the stem is divided into small pieces measuring 1–2 centimeters. Each piece is then planted in sand or soil like a complete cutting.
If the diameter of the main or parent stem is large, the cutting—similar to a mallet cutting—can be split into two halves lengthwise before planting. This method has produced satisfactory results in the propagation of mulberry and grapevines.
D) Leaf Cuttings
In some plants, leaves can also be used for propagation. Lemon and orange trees can be propagated through leaf cuttings, provided that a small portion of the parent stem remains attached to the leaf at the time of cutting.
Conditions for Successful Cutting Propagation
Plants cannot grow under all conditions. In particular, plant organs that have just been separated from the parent plant require more suitable conditions and greater care. Therefore, these conditions must be well understood and properly provided. In addition, the cutting itself must possess certain characteristics.
This section discusses the conditions and characteristics required for successful cuttings.
A) Internal Conditions
Internal conditions refer to the characteristics of the plant itself. That is, the cutting must have certain qualities so that, when placed in a suitable environment, it can develop into a healthy and vigorous new plant.
Some of these conditions include:
Age of the cutting
Depending on the plant species, the age of the cutting—meaning the age of the plant part from which the cutting is taken—varies. In many cuttings, the age is about one year, while in others it may be older. For example, trees such as olive can produce roots from branches that are several years old. Today, however, young olive shoots are also widely used for cuttings, and for optimal rooting they are kept in greenhouses where humidity is maintained by misting (mist propagation houses).
Amount of stored reserves in the cutting
Since a cutting initially lacks roots (except for root cuttings), the greater the amount of stored nutrients in its tissues, the higher the likelihood of successful rooting. Therefore, it is better to take cuttings from the parent plant during the early or middle stages of dormancy, when plant sap has not yet begun to flow and reserves have not been consumed.
Polarity or orientation of the cutting
When placing the cutting in the soil, care must be taken to ensure that the end of the stem that was oriented toward the terminal bud on the parent plant remains facing upward. If the upper end of the cutting is placed underground and the lower end above the soil, rooting will be impaired.
Nature and structure of the plant
Some plants, such as certain fruit trees and pines, are structurally and physiologically unable to produce roots from cuttings, even when all other conditions are met. Alternative propagation methods must be used for such plants.
B) External Conditions
External or environmental factors that influence the success of cuttings include the following:
Type of growing medium
The rooting medium is used to retain moisture around the cutting and provide suitable conditions for root growth. It may consist of washed sand, sawdust, peat, or mixtures of sand, peat, and water. In all cases, the medium must retain adequate moisture while also holding sufficient air between its particles.
Peat refers to materials obtained from the decomposition of organic matter in wetlands.
Today, at the East Malling Research Station—one of the most well-known research centers for rootstock breeding and production—a rooting medium consisting of a 7.5 cm layer of pine bark granules placed over a 20 cm layer of fine sand is used. The sand layer ensures proper drainage of the medium.
Air
Since air is essential for root formation, the rooting medium must be well aerated. Even mature or hardwood cuttings should be planted at a slight angle to improve access to air and bring them closer to the soil surface.
Temperature
Although the optimal temperature for rooting varies by plant species, in general, suitable temperatures range from 21–27°C during the day and about 15°C at night. Hardwood cuttings should be planted during the plant’s dormant period. To prevent the aerial parts from breaking dormancy before roots form, it is preferable to plant them on heated greenhouse benches or otherwise ensure that the rooting medium remains warm. In some cases, electric heating elements are placed in the rooting medium to provide bottom heat, which is essential for rooting cuttings of trees such as apple.
Humidity
Adequate humidity is another critical factor for successful cutting propagation. In young cuttings that retain leaves, the humidity of the surrounding air must be higher than that of the soil. For this purpose, misting systems are used in large greenhouses to provide continuous humidity, especially for young or herbaceous cuttings of plants such as olive. In these greenhouses, water is sprayed as a fine mist over the cuttings or the rooting bed. Sometimes, to prevent moisture loss before rooting, the aerial parts of the cutting are temporarily covered with plastic.
Light
Light appears to inhibit root initiation, while darkness promotes it. Studies have shown that light has a negative effect on the initiation of roots. Experimental exposure of the lower parts of poplar and willow cuttings to white light during rooting has been shown to inhibit root growth. Soft and herbaceous cuttings respond to light due to its role in photosynthesis and carbohydrate production, whereas hardwood cuttings of deciduous plants—which contain sufficient food reserves and lack leaves—root better in darkness. Naturally, once roots are formed, light becomes essential.
Preparation of Cuttings
Preparing cuttings is a simple method that requires less time and patience than seed propagation. The following points should be observed:
Hardwood cuttings are prepared during the plant’s dormant period, mostly from shoots that developed during the previous growing season. Cuttings of easily propagated plants are usually taken from autumn to early winter. These cuttings are either planted immediately in a nursery bed—an area with good drainage, irrigation, and protection where cuttings remain for one year—or directly in the orchard.
Soils that are stony, heavy, poorly structured, or prone to waterlogging in winter should not be used. Although planting cuttings in early winter is preferred, it often continues until autumn. In early spring, care must be taken to prevent the cuttings from drying out, and irrigation may be necessary.
The length of hardwood cuttings is usually 25–40 cm, with about half of their length placed underground. In areas where drying is likely, two-thirds to three-quarters of the cutting should be buried. The soil must be carefully and thoroughly prepared. If deeply plowed, cuttings can be inserted without using a shovel.
In another method, placing cuttings in black polyethylene sheets spread over the soil has yielded better results. To accelerate rooting, the base of the cutting can be treated with rooting hormones, such as indole-3-butyric acid (IBA), which is available in powder or liquid form.
After planting, water the cutting and place it inside a polyethylene bag, ensuring that the cutting does not come into direct contact with the plastic. Most cuttings require light after rooting but should be protected from direct sunlight and frost. To maintain humidity, regular misting is necessary.
When new shoots appear, this indicates that rooting has occurred. At this stage, the polyethylene cover should be removed and the cutting gradually acclimated to direct sunlight, although it should still be protected from intense summer sun.
In spring, a small amount of chemical fertilizer may be applied. The cutting must be protected from frost during the following winter, and irrigation must be carefully controlled to prevent root rot caused by excessive watering.
While cutting propagation is possible throughout the year for some plant species, it is best carried out in spring and early summer, when sap flow increases and new leaf growth begins.