These small shrubs are much loved as bonsai for their tiny flowers which may occur 2-3 times yearly, their gnarled trunks, and naturally miniature leaves. Most bonsai are S. foetida, of which many cultivars are available. Probably the two most common bonsai purchased by the casual bonsai buyer in American are Juniperus and Serissa. Judging from the number of junked junipers and shriveled Serissas, beginners would be far happier with Elm and Ficus. Serissa is a notoriously fussy bonsai. The good news is that they aren’t hard to keep alive. But considering that most people buy Serissa on impulse because the plant is so spectacular at the store, the bad news is that most buyers panic and either over or under watering the plant. You will soon discover that the Serissa will drop its leaves if it has too much water, too little water, if it’s too hot or too cold, if it’s moved, or if there is a shift in lighting or temperature. When this happens, continue to care for it as normal and it will regrow its leaves and recover.
LIGHTING – Partial sun for S. foetida, full sun for S. crassiramea. If kept indoors, it needs 1000 lumens. Use of grow lamps for 12 hours daily is beneficial. Too little light will result in leggy growth.
TEMPERATURE -Hardy to Zone 9, growers usually bring them indoors when temps drop to 50 degrees. Ideal temps range from 50-68 degrees. The plant dislikes sudden change in lighting and many die from lack of light when brought indoors.
WATERING – Keep Serissa evenly moist. It generally needs lots of water during warm weather, so much so that some authorities recommend placing it in a tray of water. Others warn against this as it encourages root rot. Serissa is not a natural water-lover like bald cypress so a water tray should not be necessary if you faithfully water at the first sign of dryness. However, if Serissa dries out, it will soon drop its leaves. If this occurs, remember to reduce watering until the leaves return or root rot may ensue. Some recommend misting in dry weather or even daily misting. Do not mist while the plant is in bloom, however, because it causes the flowers to rot. Placing them on a moisture try is another option.
FEEDING – Feed every 10-14 days during growth, every 4-6 weeks in winter. Use liquid bonsai food or half-strength plant food. Serissa likes slightly acidic soil conditions so the occasional application of Miracid is appreciated.
PRUNING & WIRING – When in bloom, remove faded flowers to encourage further flower production. Prune as needed. The Serissa is a fast grower and may need radical or repeated pruning to maintain its shape. Will bud back on old wood. In fact, some recommend occasionally pruning back beyond old growth to also help maintain shape. Wire during the growth period. It will grow air roots and is often used in exposed root or root over rock styles. Eliminate unwanted suckers extended from the base. Serissa is suitable for all styles except formal upright and broom. Also suitable for extra small to medium sizes.
PROPAGATION – Cuttings roots quite easily. Lesniewicz recommends using 4-inch cuttings in a glass of water from early summer onwards. The Samsons recommend bottom heat which would induce faster rooting.
REPOTTING – Every 1-2 years in the spring. The newly pruned roots will emit a bad odor. Prune roots moderately and use basic bonsai soil.
PESTS & DISEASES – Red spider mites, scale, wooly aphis, and mildew are all possible problems. Pests are usually not as much of a problem as a sudden change in conditions such as light, temp, etc.