The QBG seeks to preserve plants in several ways, including the vegetative propagation of plants, which is the best way to produce plants that are genetically identical to the original plant. The QBG uses several methods of propagation, the most important of which are vegetative cuttings, woody branches, air and ground laying, and accurate propagation.
Examples of models of propagation by vegetative methods used in the garden include:
1. Propagating plants by grafting
Grafting is the process of transferring part from one plant to another, so that the first grows on the second. The first is called the graft, and the second is the parent. It is a method used in the propagation of species and varieties with good productive specifications, to both produce plants free of diseases and to shorten the period of time for the growth of sustainable evergreen plants that are difficult to propagate by cuttings, laying, or other vegetative propagation methods. Grafting is one of the most important types of vegetative propagation that needs extreme craftsmanship. In hot countries, the mango tree is popular with grafting to impart a good taste to the fruit on trees with a strong root system. This method worked well for the Christ’s thorn tree.
2. Plant propagation by ground layering
Ground layering is very common among creeping plant species, and successful examples are the Arak tree and Indian Costus tree. Ground layering is done through the following steps:
- Choose a branch of the newly growing healthy plant that is close to the ground and is flexible, so that it can be bent to remain below the surface of the soil, while removing the leaves from the area to be propagated.
- At the bottom of the stem, make a small incision in the outer bark; this reveals the cambium tissue from which the roots are formed. Then add the rooting hormone around that portion.
- Place a wooden stick in the cut fabric to keep it open and bring the exposed part of the cambium tissue toward the soil.
- Tie the stem under the ground and cover that part of the stem with soil, while keeping it moist. This allows the cambium roots to grow.
- You may need to remove some leaves from the end of the wounded stem to prevent it from wilting.
- Attach the stem to an upright stick, so that it grows upright and straight.
3. Plant propagation by air layering
Air layering has been used successfully with arak, figs, umbrella thorn, vachellia flava, agarwood, and olive trees:
- Remove leaves from a healthy 3 cm branch of the growth bud. The new roots will form in that region.
- Make an annular cut into the stem, and add rooting hormone to that portion.
- Cover that part with silt or water-saturated peat moss, cover with a plastic bag, and tie carefully.
- When the young roots begin to grow profusely, cut off that portion of the stem to become a new plant with the same characteristics as the original plant.
4. Propagate plants by cuttings
This is a type of vegetative propagation used to produce plants identical to the original plant and is a fast way to produce plants. It is used by specialists in the nursery here at the QBG because it requires specialized skills and experience in plant growth. This method has been used in the QBG successfully with the arak tree, the pomegranate tree, and the olive tree:
- Cut a soft portion of the original plant 10 to 15 cm long.
- Cuttings are placed in a rooting hormone at a concentration of 2500-4000 ppm for 10 seconds.
- Pre-plant pits in pre-mixed soil, place each individual cutting in a hole and gently press to expel air pockets.
- Water them gently, with the pots placed in a plastic tunnel. Alternatively, you can put them in a transparent bag.
- Gently close the top of the bag with an elastic band, and keep this container in a warm, well-lit place but not in direct sunlight.
5. Platelet propagation
There are many plants that reproduce with plant parts, such as grapevines, roots, ground stems, and plant staples located underground. All or some parts of them can be taken and divided into small parts and then replanted again to grow and become new plants. This method has been used with ginger, Indian premium, lemon, and bananas.