THE COMPLETE OWNER’S GUIDE TO LIGUSTRUM BONSAI TREES
The bonsai is not you working on the tree; you have to have the tree work on you.
John Naka, horticulturist and master bonsai cultivator
If you’ve been interested in the hobby of bonsai cultivation for any length of time, you’ve probably already realized how expansive the practice is. Bonsai has a rich culture and a deep history surrounding it, with practitioners having often dedicated their lives to what everyone else might simply view as cute little trees.
If you consider yourself an intermediate member of the bonsai cultivation community, you may be wondering what the next logical step in your bonsai career is. Perhaps you already have a juniper, ficus, or other beginner-appropriate bonsai tree, and you’re looking to expand your collection. As you may know, some bonsai are notoriously finicky and difficult to care for—if you don’t yet have the expertise or time to dedicate to one of these kinds of bonsai, a Ligustrum bonsai tree might be the perfect solution.
Ligustrum bonsai are excellent choices for both beginners and intermediate bonsai enthusiasts. This is because they tend to be rather hearty and capable of survival in a variety of different temperatures, soils, and locations. Additionally, compared to some other popular types of bonsai, Ligustrum require a bit less maintenance. If you’re looking for a beautiful and unique addition to your bonsai collection, or a great way to start practicing this ancient art, a member of the Ligustrum family is a wonderful place to begin.
In this article, you’ll learn about the following so you can go from Ligustrum newbie to virtuoso:
- Helpful information about the Ligustrum genus and which species are most commonly used in bonsai.
- Which styles and forms of bonsai are ideal for Ligustrum.
- Proper care and maintenance for your Ligustrum bonsai, including soil and fertilizer types, watering needs, how to best conduct pruning, and more.
- Potential hazards to protect your Ligustrum from.
ABOUT LIGUSTRUM SHRUBS AND TREES
Ligustrum, also referred to as a privet, is a genus of approximately 50 different species of shrubs which sometimes form into trees. These plants are most commonly found in Europe, Australia, Asia, and Northern Africa, but can be cultivated in most environments with relative ease. In some areas the plant is considered a pest, because most species can spread quite rapidly and produce berries which are somewhat poisonous if consumed. In fact, Australia has banned the cultivation of Ligustrum. However, despite these potentially negative properties, the plants are quite popular for bonsai because of their hardiness and aesthetic appeal.
In bonsai form, Ligustrum is quite beautiful. The bark is generally smooth and light, and in the spring most species will bud with white flowers. In the fall, dark purple berries will form. While there are approximately 50 species of Ligustrum, there are three species which are most common for use with bonsai. If you’ve acquired your Ligustrum from a nursery, it’s likely that that yours is one of the species below.
CHINESE PRIVET (LIGUSTRUM SINENSE)
The Chinese privet, or Ligustrum Sinense, is native to China, Vietnam, and Taiwan, however it has been naturalized to much of the Northern and Southern United States. It’s generally used as an ornamental plant for hedges in landscaping, and in fact has become so popular in the Southern United States that it’s escaped cultivation and runs wild in over one million hectares. As bonsai, the Chinese Privet is popular for its wide trunks and reasonable degree of malleability for styling.
OVAL LEAF PRIVET (LIGUSTRUM OVALIFOLIUM)
The oval leaf privet is a favorite of the genus for bonsai for its wide availability, beautiful white flowers which appear in the summer, and evergreen oval shaped leaves. Ligustrum Ovalifolium is also native to Asia, mostly growing in Japan and Korea. In some nurseries it may be labeled as a Japanese Privet, however it’s worth noting that this species is actually different than Ligustrum japonicum. If you’re out and looking for this specific species, keep that in mind.
This species of Ligustrum grows quickly, and unlike some of its brethren, grows much taller and wider when left unchecked, capable of reaching 10-15 feet in height and width. The leaves are green on the top, and yellowish green on the bottom. The fruits, which appear as dark purple drupes, are poisonous to people as with other Ligustrum species, but will be safely eaten by birds—important to remember if you keep your bonsai outside.
COMMON PRIVET (LIGUSTRUM VULGARE)
Ligustrum Vulgare, or the common privet, is a species of Ligustrum from Europe and parts of Africa and Asia. These shrubs don’t grow quite as large as oval leaf privets, reaching around 9 feet tall. They differ from other species with their darker bark which has lenticel spots, and their fruits are glossy and black. However, the leaves are still green and the flowers are a creamy white color. Several cultivars exist with slight differences between them, so when you’re in a nursery, expect some minor variations even though this Ligustrum may still be called a common privet.
STYLING A LIGUSTRUM BONSAI
Ligustrum bonsai are typically best styled in the following shapes or forms:
INFORMAL UPRIGHT.
In this style, the bonsai has been manipulated to appear as a natural tree might grow; the trunk is upright and ‘S’ shaped, and at each turn in this pattern branching should occur. The trunk will be thicker at the base than at the top of the bonsai.
SLANTING.
Thanks to Ligustrum’s relative strength and hardiness, the slanting form is possible to achieve. As you might imagine a tree would grow if it were in a predominantly shaded area, or if it were subjected to constant winds blowing in one direction, the slanted style of bonsai involves the tree leaning approximately 70 degrees relative to its base. Ligustrum in this style generally have slightly bent trunks which are still thicker at the bottom than at the top.
CASCADE.
A Ligustrum in the cascade bonsai style are intended to emulate the way a tree might grow if it were on the precipice of a steep cliff. The trunk grows downwards in an upside down ‘U’ shape, and pots are typically taller to accommodate this “drooping” effect. Branches grow horizontally, which is not only typical in nature, but will help to stabilize and balance the tree.
SEMI-CASCADE.
This style of bonsai is notoriously difficult to achieve for some species of tree or plant, but Ligustrum takes to it quite well. Think of this style as the less extreme version of the cascade style, as the tree grows upward for a short length, and then bends outward to the side and down a bit. This is commonly seen in nature when a tree is leaning over a river or lake.
It is worth mentioning here that
FORMAL UPRIGHT
is perhaps not the best style for Ligustrum, as this is not how the plant would grow in nature—thus you may have a harder time getting your bonsai to conform to this style, although as with most things in bonsai, it is not impossible.
LIGUSTRUM BONSAI CARE AND MAINTENANCE
While Ligustrum bonsai are noted for their hardiness, they still must receive some degree of attention and care from their owners. In the below sections you’ll learn about the most important facets of Ligustrum ownership.
POSITIONING
Ligustrum are capable of thriving without their owners having to be overly concerned regarding placement. For best results, place your bonsai in an area where it will receive a mixture of sun and shade. In the case of nearly all Ligustrum species, err on the side of more shade when in doubt.
While Ligustrum is commonly marketed as an “indoor” bonsai species, it’s worth noting that this is something of a misnomer: there are no “indoor” trees in nature. However, your Ligustrum bonsai will be capable of survival both indoors and out.
If you plan on keeping it outside, it will only need protection (or to be brought indoors) in rather extreme temperatures. Ligustrum owners report a wide range of temperatures that the tree can survive in, going as cold as below zero degrees Fahrenheit. However, if it’s winter and you’d like to play it safe with your bonsai, bring your Ligustrum inside once the thermometer dips below 20 degrees Fahrenheit.
SOIL
As with most elements of their environment, Ligustrum bonsai are not outrageously picky concerning their soil—in fact, they can happily survive in “poor” soils which would easily cause the demise of other bonsai. However, if you’d like to provide your Ligustrum with the ideal soil, try and find a blend that’s around 60% aggregate (the “dirt” part of soil) and 40% organic (plant and animal residues). Ligustrum bonsai owners have also reported success with 100% Akadama (red ball earth), a commonly used mineral for bonsai and other potted plants.
Aggregate for a Ligustrum might be composed of decomposted granite, diatomaceous earth, or even clay pellets commonly used for some species of orchid. The organic matter in the soil can come from nearly any pre-composted potting soil. Both components are readily available at most garden centers.
Be prepared to re-pot your Ligustrum every 24 to 36 months—see more below under “Potting and Repotting”.
FERTILIZER
For year-round feeding, which should take place once every two to three months, a general fertilizer is more than appropriate for a Ligustrum bonsai. However, if during the spring and early summer you wish to promote ideal growth and flowering, you may find benefit in using a nitrogen rich fertilizer.
WATERING
Unlike some other species of bonsai, Ligustrum bonsai do not require watering as often (or with as much precision timing) as others. However, your Ligustrum will benefit from regular watering—approximately once per day. If the weather is especially warm, you may need to water it twice, but keep in mind that even considering the hardy nature of the Ligustrum it can be over-watered, which can result in root-rot. A pot and soil combination which promotes easy draining can help prevent this, and you may even wish to invest in a moisture meter in order to remove the guesswork from watering.
A good rule of thumb is to water your Ligustrum if the topsoil looks and feels dry.
POTTING AND REPOTTING
Potting requirements for Ligustrum are quite lax. Generally speaking, select a pot which will accommodate your intended bonsai style, while being large enough to provide the plant for room to expand its roots. The area where you’ll need to pay more attention as a Ligustrum owner is in repotting and root pruning.
If your Ligustrum is quite young, you’ll likely want to repot it once a year. Older bonsai will only require repotting every 24 to 36 months. The Ligustrum genus is known for a dense and quite fibrous system of roots, and these will need to be trimmed at the same time that you move your bonsai to a larger pot. In fact, without pruning the roots, your Ligustrum will likely stop growing. This is due to the roots becoming so dense that—somewhat ironically—they cut off the flow of nutrients necessary for growth.
PRUNING
Ligustrum can be shaped and trained through both pruning methods and wiring methods (which we’ll explore next). Generally, you can expect long shoots to grow during the growth season during late spring and early summer. These shoots should be trimmed from the bottom of the trunk quickly, as they can prevent the upper branches from receiving nutrients.
If you choose to prune the rest of your Ligustrum as well, the clip and grow method will likely produce the best results. This method is simple to follow for Ligustrum—allow the branches to grow out, perhaps a bit longer than you’d allow for other species. Then clip, wait for regrowth, and repeat. This can result in a natural bending appearance in the branches that develop over time.
WIRING
Wire shaping works well for Ligustrum thanks to the flexibility and durability of the bark of this genus. If you choose to wire shape, be vigilant—Ligustrum grows quickly, and branches will thicken rapidly, and this can result in scarring if left unchecked for too long. Wire scars are a common aesthetic problem for other species, but Ligustrum tends to heal from these markings rather quickly as long as the wires were not left on for too long. If you choose to wire your bonsai, you’ll see best results if you do so during the late spring or early summer during the growth period.
POTENTIAL HAZARDS
The most common issues encountered by Ligustrum bonsai owners—and bonsai owners in general—are insects and disease. However, in most cases, both of these problems can be easily avoided with some simple preventative care.
INSECTS
Aphids, spider mites, whiteflies, and other common plant insects can become a problem for a Ligustrum bonsai, but are easily preventable.
Aphids are probably the most common plant pest, and if you’ve been interested in bonsai or botany for any duration of time, you’ve likely dealt with them before. Easily identified by their pear shaped bodies, these insects tend to cluster together on the tips of a Ligustrum’s shoots and leaves.
Spider mites—called this due to the “spider web” type patterns that can be left on leaves and branch tips after these little buggers eat through them—you’ll notice very small little brown or red infestations on the tips of branches. They may even appear to move in particularly large infestations.
Whiteflies are easy to miss if you aren’t paying attention. They simply look like small bits of ash or gray discoloration on leaves. If you notice this, or leaves seem to be turning yellow or start dropping off for no apparent reason, it very well may be the result of a whitefly infestation.
To prevent or remove insects like these, use a standard insecticide in a spray bottle at half the usual rate of dilution. Spray your Ligustrum conservatively once every month if indoors, and once every two months if outdoors. Never spray your Ligustrum (or any other bonsai) when the soil is dry, as the insecticide will then be absorbed by the soil.
It’s unlikely with this genus, but if your Ligustrum responds poorly to insecticide, further dilute the solution during the next round of spraying, and spray the bonsai 24 hours after each session with clean water.
DISEASES
Root rot is by far the most common disease which can affect your Ligustrum bonsai. This can be identified by brown roots—particularly on Ligustrum species which have a lighter bark—or roots with a “mushy” or soft texture. The leaves on the tree will likely become discolored and yellow or brown, and any new branches that appear during the growth season will be weak.
Root rot is easily prevented by not over watering your bonsai, but if you’re having difficulty telling whether or not this is something you’re doing, there are a few suggestions you can implement.
First, ensure that the pot and soil that you’re using for your Ligustrum has proper drainage. If you’re following the advice from earlier in this piece, your soil should be roughly 60% aggregate—if this is the case, odds are your soil isn’t the culprit, so consider repotting your Ligustrum to a pot with better drainage.
You may also wish to purchase and use a moisture meter. This can be a big help, particularly for novices to bonsai, but for anyone who needs to get used to the watering requirements of a new tree. A general rule of thumb is to water your Ligustrum only until water begins to gently run out of the holes at the bottom of your pot.
Ligustrum owners may also find that their bonsai is susceptible to scabbing or “canker” diseases, which manifest in the bark of your tree swelling or bloating, leaves turning yellowish or brown, or growth being stunted. For most species of bonsai tree this kind of infection occurs after pruning, however it’s more common to see this in Ligustrum after the growth season if the owner decided to use too much of a nitrogen rich fertilizer.
To prevent, make sure that you’re not overdoing it with nitrogen fertilizer—follow the instructions as accurately as possible—but if it’s already too late, the solution to a canker infection is to cut off the affected areas of your Ligustrum. This might be painful to do, but it’s the only way to prevent this kind of disease from spreading, and you’ll be saving the tree’s life. After you’ve trimmed off the affected areas, your Ligustrum will benefit from the application of a bonsai “wound paste,” (or “cut paste”) which is a form of sealant that’s readily available in many garden centers or bonsai shops.
FINAL THOUGHTS
With proper care—and even sometimes without it—you can expect your Ligustrum bonsai to thrive for many years. Whether you have a Chinese, oval leaf, or common privet, or any of the dozens of other species within this genus, you’ll be delighted by this tree’s ability to withstand different environments, temperatures, lighting, and soil types. Ligustrum bonsai can take just about anything their owner’s throw at them, which is why they’re so ideal for beginners or busy individuals.
If you’re attempting a new style or shape for the first time, especially if you’re learning to wire shape a bonsai, Ligustrum again stand out as an excellent choice. They’re resistant to wire scarring and can take a certain degree of the “abuse” that’s common for learners of a new shape.
It’s safe to say that Ligustrum bonsai deserve a spot in any collection. Not only are they very tough as far as bonsai trees go, they can be made to appear very beautiful. It’s a common misconception made by beginners to the practice of bonsai that in order for a tree to be beautiful it must be exotic or rare—as though this practice were some kind of competition.
While rare bonsai are nice and might even eventually become the cornerstone of your collection, Ligustrum shouldn’t be ignored just because they’re common. These trees can be shaped into long-lasting, hardy, gorgeous examples of bonsai at its best.