Grafting Techniques in Carob Tree
The way to establish a productive garden in carob and to get economical products from wild trees in nature is through grafting. About half of the trees grown from seeds are male and do not produce any pods; the fruit characteristics of the female ones vary from tree to tree. Thanks to grafting, male or wild trees that produce poor quality fruit can be transformed into a known and productive variety.
In this article, we discuss why carob is grafted, the main grafting methods used (T eye, patch, chip and scion grafting), grafting time, rootstock selection and grafting of wild trees in natural populations in the light of sources.
Why Is Carob Grafted?
Carob is a foreign pollinated species; therefore, each tree grown from seed is genetically different. According to the monograph published by IPGRI, wild and illegal carob reproduce by seed, while cultivated varieties are propagated vegetatively as clones. In the monograph, it is emphasized that the transition to vegetative propagation in carob, as in other fruit and bark fruit trees, is the breeder's solution to the great variability brought about by sexual reproduction (Batlle and Tous, 1997).
The graft has three main purposes in carob:
| Securing gender | In natural populations, about half of the trees are male and do not produce pods. With grafting, the tree is transformed into a female or hermit variety. |
| Fixing fruit quality | Grafted varieties usually produce larger and more fleshy pods than wild types. |
| Regulating pollination | The need for pollinators can be met by grafting male or female eyes to some trees in the garden. |
One of the reasons why grafting is so decisive in carob is the difficulty of other vegetative methods. The IPGRI monograph states that carob does not root easily with cuttings and can only be easily propagated by eye grafting. Although promising rooting rates have been obtained in some genotypes in experiments on propagation by cuttings, it is reported that this method has not reached a level that will give consistent results suitable for commercial sapling production. It is stated that there are no reports of successful cultivation of plants produced in the laboratory in the field in tissue culture trials.
According to an assessment cited in the monograph, this difficulty in vegetative propagation is the reason for the relatively late domestication of carob in the Old World.
Rootstock: The Foundation of the Graft
As rootstocks in carob, seedlings grown from open pollinated seeds are used. The IPGRI monograph states that these seedling rootstocks vary greatly in terms of growth strength, growth pattern and cold resistance, but no rootstock trials have been carried out and there is no selected rootstock. The basic condition is that the rootstock forms a well-developed root system.
Wild carob seeds are generally used in rootstock production in Turkey. In the Alanya Carob geographical indication certificate, it is stated that wild carob seeds, called "delice seeds", are used in germination and saplings are produced by grafting the local carob variety to the seedlings obtained (Turkish Patent and Trademark Office, 2025). We discuss growing rootstocks from seeds in detail in our article "How to Grow Carob from Seed?".
When is the rootstock ready for grafting?
It takes time for the rootstock to reach the thickness suitable for grafting. According to the geographical indication document, it takes about 1.5–2 years for the seedlings to reach a diameter of over 10 mm for grafting after germination; in the same document, it is stated that the seedlings are grafted when they reach the "thickness of a pencil". In the document, it is emphasized that the grafting type, grafting time, seedling diameter and timely cultural procedures after grafting affect the grafting success in seedlings.
In the IPGRI monograph, it is stated that rootstocks should be grafted 1 year after germination in the nursery or 2 years after germination after planting in the garden. Julia Morton also states that eye grafting is done when the rootstock trunk reaches a thickness of at least 1 cm (Morton, 1987).
In the Nursery or in the Garden?
Grafting in carob can be done in two different stages. According to the investor guide of the Ministry of Agriculture and Forestry, ungrafted saplings can be planted in the garden facility and grafted at the planting site a year later, or grafted grafted saplings with 1+0 or 2+0 aged grafts can be used in the nursery.
The IPGRI monograph states that, unlike other fruit trees, carob is not usually grafted in the nursery, and that the graft made in the garden one year after planting is superior in terms of the tree's growth power. When establishing a new garden, rootstocks are planted in late February or March and usually grafted in spring the following year.
Graft Methods Used in Carob
The most common grafting methods in carob are bud grafting. According to the IPGRI monograph, the main methods used are T-budding, chip budding, and patch budding (Batlle and Tous, 1997). In the feasibility report of the Western Mediterranean Development Agency, T eye, chip, and patch budding are listed among the graft techniques used in carob (Erbaş, 2024).
| Method | Suitable rootstock thickness | Feature cited in sources |
|---|---|---|
| T-budding | 1–2 cm | The most productive and common method in spring |
| Patch eye graft | Thicker than 2 cm | Mostly in the garden, in spring or autumn |
| Chip budding | May be useful for rootstocks thinner than 1 cm | Requires full overlap of cambiums |
| Dilcikli (British) scion grafting | Pencil-thick scrooks | One of the methods used in sapling production in Alanya |
T-budding
According to the IPGRI monograph, T eye grafting is the most efficient and most common method applied to rootstocks with a diameter of 1–2 cm with well-developed eyes taken from the previous year's scion wood in spring (April-May). It is done when the rootstock bark is easily removed, that is, when the rootstock is active. A T-shaped incision is made in the rootstock bark, the eye removed from the scion branch in the form of a shield is placed in this incision and tied tightly. Morton also states that shield-shaped eye grafting is used in Cyprus, California and Mexico.
Patch budding
Patch eye grafting requires thicker rootstocks. According to the monograph, it is applied to rootstocks thicker than 2 cm and is therefore mostly done in the garden, spring or autumn. In this method, a rectangular piece is removed from the rootstock bark and replaced with a piece of eye-bearing bark of the same size. Like the T eye graft, patch grafting is done when the rootstock bark lifts easily.
Chip budding
In the monograph, it is stated that the eye retention rate is low in rootstocks thinner than 1 cm, and that chip eye grafting may be beneficial for such plants, but in this method, the cambium tissues of the rootstock and scion must be correctly matched. In the Alanya Carob geographical indication certificate, chip eye grafting is counted among the methods used in sapling production.
Scion grafting
In the geographical indication document, the three methods used in sapling production in Alanya are listed as follows: chip eye graft, tongue eye graft and tongue (English) pencil graft. Tongue scion grafting is a suitable method for rootstocks and scions of similar thickness, in which the rootstock and scion are cut obliquely and joined by opening the tongues to interlock. Morton also states that eye grafting and pencil grafting are sometimes used together in carob.
General Rules for Success
The practical rules highlighted in the sources can be summarized as follows:
- A sharp grafting knife should be used for smooth cuts (Batlle and Tous, 1997).
- Various materials can be used as graft ties; the most common is the plastic bond.
- Pencil eyes should be taken from the well-developed wood of the previous year.
- If the graft fails, the rootstocks can be re-grafted in September.
Grafting Time
The grafting time for carob varies according to the method used, the environment and the region. According to the IPGRI monograph, grafting is usually done in the spring, from April to the beginning of June, when the pen eyes are mature and the rootstock bark is easily removed. If the graft fails, re-grafting can be done in September. Morton also states that bud grafting is done in February-March in Cyprus and in April-June in California and Mexico.
In the Alanya Carob geographical indication certificate, it is stated that grafting is done between the end of November and the end of March in sapling production. According to the document, the grafted saplings start to grow in an average of 20-30 days and the shoots reach 10-15 cm in length in the spring. This calendar is different from the eye grafting calendar, which depends on the removal of the rootstock bark in the garden; in practice, the grafting time, method and growing environment should be determined by evaluating them together.
A study conducted in a natural carob population in Turkey dramatically demonstrated the impact of grafting month on success. In this study, the retention rate reached 100 percent in grafts administered in April, while this rate decreased to 36.11 percent in grafts administered in May. Researchers recommended April as the optimal grafting time (Balkıç et al., 2026).
Making Male and Wild Trees Productive with Grafting
Perhaps the most valuable use of the graft in carob is the transformation of existing unproductive trees. There are many wild (delice) carob trees on the Mediterranean and Aegean coasts of Turkey. Some of these trees are male and do not produce any crop; the pods of the female ones are mostly small and less fleshy. These trees, which have a strong root system, can be transformed into a productive variety in a short time with grafting.
Rejuvenation and Graft: A Research from Turkey
In the research conducted by Akdeniz University researchers in a natural forest population, unproductive young and old carob trees were reconstructed by two different methods: hard pruning and burning with hard pruning. The shoots formed after these processes were grafted in April and May 2015 (Balkıç et al., 2026).
The main findings of the study are as follows:
- Both the method and the age of the tree significantly influenced the number of shoots formed.
- The highest number of shoots (114.44 shoots per tree) and the thickest, longest shoots were obtained by hard pruning in older trees.
- The grafting month determined the grafting rate, not the method and tree age: 100 percent in April, 36.11 percent in May.
- It was concluded that both young and old trees are suitable for restructuring, and hard pruning is the recommended method.
Researchers state that orchards established from seeds have a long youth period and require irrigation in the first years; and that the transformation of unproductive trees in natural areas can accelerate carob production and support sustainable cultivation in some regions of Turkey (Balkıç et al., 2026).
Crown Grafting and Male Branch Dropping
In the IPGRI monograph, it is stated that in existing orchards with pollination problems, some female trees can be grafted with a male or male scion with a top graft. In traditional practice, if the rootstock is male, a male branch belonging to the rootstock is left in the middle of the grafted female tree, and if the rootstock is female, a male or hermit eye is grafted onto the tree. In the monograph, it is also stated that a project is being carried out to graft male trees in Morocco in order to increase fruit production. Morton also states that some female trees in Southern Europe are grafted with male branches.
This approach prevents planting separate male trees in the garden from taking up space. We discuss the pollinator tree ratio in detail in our article "Male, Female and Male Trees in the Carob Tree".
Care and Fruiting After Grafting
Care after grafting is as important as the success of the grafting. In the geographical indication certificate, it is emphasized that timely cultural procedures after grafting affect success. The IPGRI monograph also recommends supporting the broodstock against the prevailing wind and watering them regularly in the first summer.
With grafting, the fruiting time is also shortened. According to the observations conveyed in the monograph, trees begin to bear fruit in the 5th-6th year in gardens established with grafted saplings, and in the 7th-8th year in trees grown from seeds and grafted later. While some varieties start to produce 4-5 years after grafting, it has been observed that hereditary types usually bear fruit in the 2nd-3rd year after grafting. Morton also states that grafted trees start to bear fruit in the sixth year.
Frequently Asked Questions
In which month is carob grafted? Eye grafting in the garden is usually done in the spring, between April and the beginning of June, when the rootstock bark is easily removed. In a study conducted in Turkey, a retention rate of 100 percent was obtained in grafts made in April and 36 percent in May.
Which graft method is most commonly used in carob? In international sources, T eye grafting is shown as the most efficient and common method. Patch eye grafting can be preferred for thick rootstocks and chip eye grafting can be preferred for thin rootstocks. In Alanya, chip eye, tongue eye and tongue pencil grafts are used in sapling production.
Does the male carob tree bear fruit with grafting? Yes. When a male tree is grafted with a female or herbaceous variety, the grafted part has the characteristics of that variety and can bear fruit.
Can carob be propagated by cuttings? Carob is difficult to root with cuttings. Although rooting has been achieved in some trials, this method has not reached sufficient consistency for commercial sapling production; the common propagation method is grafting.
From Productive Carob Trees to Products with Carob Türkiye
Grafting is a basic method in carob that ensures both the efficient establishment of new gardens and the introduction of wild trees in nature into the economy. Grafting done at the right time and with the right technique paves the way for the tree to produce quality products for decades.
At Carob Türkiye, we supply carob fruit, crumbs, flour/powder, seeds, and extracts. Our Products Carob Fruit and Our Products You can review it on the pages. For your wholesale and export requests Contact Now You can contact us on our page.
Domestic resources
Balkıç, R., Güler, S., Gübbük, H., "Reconversion of unproductive young and old carob (Ceratonia siliqua L.) trees into production", Black Sea Journal of Agriculture, 9(1), 45–50, 2026. doi.
org/ 10. 47115/ bsagriculture. 1762797 Turkish Patent and Trademark Office, "Alanya Carob / Alanya Carob – Mahreç Sign, Registration No: 1705", 2025. ci.
turkpatent. gov. en/ Files/ GeographicalSigns/ 7bbe4a8b- 399… Republic of Turkey Ministry of Agriculture and Forestry, General Directorate of Forestry, "Carob Orchard Facility Project Feasibility Report and Investor Guide", Ankara, 2020. Eskisehir.
agriculture. gov. en/ DocumentsArchive/ Yat%C4%B1r%C4%B... Erbaş, S., "Carob Agriculture and Industry Feasibility Report", Western Mediterranean Development Agency, Publication No: 153, ISBN 978-605-4752-49-2, 2024. DEVELOPMENT LIBRARY.
gov. en/ assets/ upload/ files/ Keciboy... Foreign sources
Batlle, I., Tous, J., "Carob tree. Ceratonia siliqua L. Promoting the conservation and use of underutilized and neglected crops. 17", Institute of Plant Genetics and Crop Plant Research, Gatersleben / International Plant Genetic Resources Institute, Rome, 1997. ISBN 92-9043-328-X. hdl.
handle. net/ 10568/ 104277 Morton, J. F., "Carob", Fruits of Warm Climates, Miami, 1987. Growables.
Scientific Resourcesorg/ information/ TropicalFruit/ CarobMorton. htm
