Plant propagation is the process of creating new plants from a parent stock. For citrus, this is often done to expand a collection, maintain specific fruit characteristics, or grow trees suitable for container life. Unlike many other plants, citrus propagation often involves a two-part process where the desired fruit variety is grown atop a different, more resilient root system. The choice of method—seed, cutting, or grafting—depends on the grower’s goal for the resulting tree.
Propagation by Seed
Growing citrus from seed is the simplest method for the home gardener, requiring minimal special equipment. Clean the seeds of any fruit pulp by rinsing them to prevent fungal growth. Plant the seeds soon after extraction, as citrus seeds lose viability quickly, about a quarter to a half-inch deep in a sterile, well-draining potting medium.
The soil should be kept consistently moist and warm, ideally around 70 degrees Fahrenheit, promoting germination within two to three weeks. The main drawback is that the resulting tree will likely not be “true-to-type,” meaning the fruit may differ from the parent due to genetic variability. Furthermore, trees grown from seed enter a juvenile phase and can take five to fifteen years before they produce fruit. Seed propagation is primarily used to grow hardy rootstock for later grafting.
Propagating Citrus Through Cuttings
Propagating citrus through cuttings is a form of asexual reproduction that yields a genetic clone of the parent plant. This method ensures the new tree will have the exact same fruit characteristics as the original. The best material is semi-hardwood taken from healthy, disease-free branches, typically during the late spring or early summer. A cutting should be roughly four to six inches long and include several leaf nodes.
Prepare the cutting by making a clean cut just below a node and removing the leaves from the lower half. Trim the remaining upper leaves to reduce water loss through transpiration. The base of the cutting must be dipped into a rooting powder or gel containing a root-stimulating hormone, such as indole-3-acetic acid (IAA) or naphthalene acetic acid (NAA). Cuttings are then inserted into a highly porous rooting medium, such as a mix of perlite and peat moss. Success requires creating a high-humidity environment, often achieved by covering the pot with a plastic bag or dome, to minimize stress until new roots form.
The Art of Grafting and Budding
Grafting and budding are the most reliable methods for commercial propagation because they combine the desired fruit variety with a robust root system. This technique ensures the tree produces “true-to-type” fruit and confers important traits like disease resistance, tolerance to specific soil conditions, or dwarfing for container growing. A finished citrus tree consists of the scion (the desired fruit-bearing wood) and the rootstock (which forms the base and root system).
The fundamental principle of a successful graft is the precise alignment of the cambium layers of both the scion and the rootstock. The cambium is the thin layer of actively dividing cells located between the wood and the bark. Budding, a specialized type of grafting, is often preferred for citrus.
T-Budding
T-budding involves creating a T-shaped incision in the rootstock’s bark and inserting a single bud, attached to a sliver of bark, beneath the flaps.
Chip Budding
Chip budding involves removing a small wedge of wood and bark from the rootstock and replacing it with a corresponding piece containing the scion bud.
Specialized tools, like a sharp budding knife, are used to make clean, smooth cuts. The union must be immediately and securely wrapped with grafting tape or Parafilm to prevent desiccation and hold the cambium layers in close contact while they fuse. Successful grafts typically show a healthy, green bud after two to four weeks.
Essential Aftercare for New Citrus Plants
Once a cutting has rooted or a graft has successfully taken, the new citrus plant requires careful attention. If the plant was in a high-humidity environment, it must be “hardened off” by gradually exposing it to lower humidity and more direct sunlight over several weeks. This slow transition prevents leaf scorch and shock.
New citrus plants thrive in a well-aerated, fast-draining potting mix; heavy garden soil or mixes that retain too much moisture can damage the developing root system. Place the new plant in a location that receives full sun, as citrus demands high light levels for strong growth. Watering is the most crucial step during the first year. The soil should be kept consistently moist but never waterlogged, which is a common cause of failure. Deep watering two to four times a week is a general guideline for the first year, but frequency should be adjusted by checking the top one to two inches of soil for dryness.