Ligustrum will tolerate indoor growing conditions as long as humidity levels remain reasonably high, a humidity tray will help a lot. A Ligustrum that’s been inside shouldn’t be put outside in the winter without going through the gradual cooling of fall weather. Give it lots of light but not direct afternoon sun.
Ligustrum are very tolerant of both full sun in the summer and deep shade. They are cold hardy and can handle temperatures in the 20s but should be brought inside if it gets below 20° F. The colder the temperatures a Ligustrum are exposed to, the more leaves they drop. This is a natural reaction and causes no permanent damage even when specimens lose all their leaves in severe cold. New growth comes back quickly in the spring. Ligustrum that are left outside during the winter must have spent the autumn outside in order to acclimatize to the cold.
DO NOT PLACE TREES THAT HAVE BEEN INSIDE STRAIGHT OUTSIDE IN THE WINTER. It is better to leave them inside until spring.
Bonsai trees live in small pots and their world dries out much quicker than plants in the ground or in bigger pots, so close attention should be paid to watering. Check and water your bonsai every day. Striking a balance between not enough water and too much water can be a bit tricky but is very important. Give it enough water to keep it from drying out and remaining dry. A Ligustrum will tolerate over watering well and will wilt if it gets too dry for too long.
Water thoroughly and deeply when it needs water and let it catch its breath before watering again. An old bonsai watering trick is to place the entire pot in a sink of water an inch or two deep and let the water absorb from the holes in the bottom of the pot. Another favorite way to know if it needs watering is to lift it. You can get a sense for whether it needs watering by its weight.
An inexpensive moisture meter takes the guesswork out of watering. We sell them. Water slowly so it absorbs into the dirt, otherwise the water will run all over your table. Mist occasionally with a spray bottle too. It helps take the burden off of the roots especially when it’s very hot and dry out. We pot our bonsai trees specifically to drain well, so it’s almost impossible to over water.
Leaves want humidity to keep them green and healthy. Any time your tree is inside, the air is very dry. Mist often during the day. Avoid putting your Bonsai near a draft or vent, which dries out the foliage. A humidity tray is a great way to increase humidity. These shallow trays filled with small stones have water in the bottom of the tray. Make sure the water does not reach the bottom of the Bonsai pot. As the water evaporates, it creates a moister environment.
When new growth appears in the spring it’s time to start feeding your bonsai. Use an organic liquid fertilizer or a chemical fertilizer diluted to one half strength. Fertilize every two weeks during the growing season and once a month in the winter.
Trim to shape through the growing season; remove overlarge leaves and shoots with overlong internodes. Heavy pruning should be done during the late winter or early spring before new growth starts.
Good wiring techniques are used to train Bonsai trees into different shapes and styles. Use the thinnest training wire that will hold the branch in the desired position. Wiring can be carried out anytime, though spring-summer is best. DO NOT WIRE A BONSAI JUST AFTER REPOTTING. Wind the training wire in the direction the branch is bent in order to keep the wire from loosening. Wrapping the wire too tightly will cause scarring. Wrap just tight enough to get the job done. Begin at the base of the Bonsai tree and slowly wrap the wire around the trunk to anchor. Continue along the branch you wish to train. Repeat the process as needed. After about 6 weeks, the branch should be able to maintain the shape on it’s own, and the wire can be removed. Cut the wire carefully from the branch. DO NOT UNWIND WIRES. This could cause the branch to break.
You should repot your Ligustrum annually in the spring (as new buds extend) using a basic soil mix. After repotting, water thoroughly and place Ligustrum in a shady location for several weeks so new roots can grow.
Insects and Diseases:
The usual minor stuff can bother a Ligustrum, like Aphids, leaf spot, scale insects, spider mites, whiteflies and root rot. These can be attacked with the use of insecticides and fungicides in the form of sprays, soapy rinses, or systemic poisons. Use standard insecticides at half the dilution rate.
Spraying your Bonsai once every month or two with a non-toxic insect spray is recommended. Soaps should be rinsed of the next day. DO NOT SPRAY WHEN SOIL IS DRY.
Aphids are soft-bodied insects with pear shaped bodies. They cluster on buds, leaves and tips of shoots. Aphids feed on plant juices causing poor plant growth and distorted leaves. Most products used for aphid control work as contact insecticides. The aphids must be hit directly with spray droplets so they can be absorbed into the insect's body. Insecticidal soaps work well against aphids.
Mites also like to infest the Ligustrum. Identified by small moving pinpoints of red or brown on branch tips, severe infestations leave “spider webs” on branch tips and yellow leaves all over the tree.
Whiteflies resemble bits of ash and suck juices from leaves. Infested leaves turn yellow, die or drop off and are covered with a sticky substance.
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