Flowering White Serissa is an evergreen or semi-evergreen flowering shrub that is native to Southeast Asia and is found commonly in India, China and Japan. It grows in wet meadows and open sub-tropical woodlands. Also known as “Snow Rose” or “Tree of a Thousand Stars” because of the tiny white flowers that it produces 2-3 times per year. It’s naturally miniature leaves and gnarled trunk makes it a popular Bonsai tree. With the right conditions it can flower continuously, though there are more flowers from spring to autumn.
Serissa are primarily outdoor trees but can be put inside during the winter. They grow best in high light and thrive in sunny, warm locations. Better lighting conditions will result in more frequent flowering. The best location for your Snow Rose is in full sun but be careful not to place it where it gets direct afternoon sun in the summer. Use a humidity tray to keep moisture levels up.
Although some people leave their Snow Rose outside during the winter, the Serissa should be kept indoors when temperatures begin dipping below 55° F. When bringing an outdoor Serissa inside, do not position near a heat source, or it will lose leaves. If kept outdoors year round, leaves will drop as temperatures become colder.
Generally, any changes in light, temperature and watering will cause a Snow Rose to drop its leaves. Don’t panic, it’s okay…the tree will soon re-grow its leaves.
The more sunlight and warmth your Bonsai receives, the more often it will need water. More Bonsai die due to improper watering than any other cause. Check your Bonsai daily by sticking your finger into the soil. Do not water the tree if the soil is damp or cool. Bonsai generally need to be watered every couple of days, but there is no set schedule. When the topsoil feels dry, water thoroughly and deeply. An old Bonsai watering trick is to place the entire pot in a sink of water an inch or two deep. Let the water absorb from the holes in the bottom of the pot. An inexpensive moisture meter takes the guesswork out of watering.
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 but, DO NOT MIST WHILE IN BLOOM as this causes the flowers to rot. 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
Fertilizing a Bonsai is essential to its health because nutrients in the soil are washed away with each watering. Fertilizer is like vitamins and minerals for a plant. 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. Most Bonsai should be fertilized once or twice per month during the growing season and once a month in the winter. Water your tree BEFORE fertilizing. DO NOT FERTILIZE A WEAK OR FRESHLY REPOTTED TREE! This will cause stress to the tree by burning the roots.
To keep a Bonsai miniature, it needs to be trimmed and pruned as new growth appears. Never remove all the new growth at one time. Shape is determined by the overall look that you want to achieve. Sit at eye level with your Bonsai tree and use Bonsai trimming shears. Your cuts should be smooth or slightly concave so the wound will heal quickly.
When in bloom, remove fading flowers to encourage further flower production. Prune as needed; Serissa is a fast grower and may need to be pruned often to maintain its shape. Serissa will grow air roots and is often used in exposed root over rock styles except formal upright and broom.
Wire to shape your Snow Rose during the spring and summer growing season. 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. 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.
A Bonsai should be repotted periodically to supply the plant with fresh soil. When the roots can be seen growing out the sides of the Bonsai container...it’s time. For a Serissa this occurs every 1-2 years in early spring. Prune roots moderately. After repotting, water thoroughly. DO NOT FERTILIZE FOR 3-4 WEEKS.
INSECTS & DISEASE:
Serissa are generally not as susceptible to pests and diseases as they are to sudden changes in conditions such as light, temperature, etc. But, keep an eye out for the usual suspects such as aphids, spider mites, scale, and root aphids that are common Bonsai pests. These can be attacked with the use of insecticides and fungicides in the form of sprays, soapy rinses, or systemic poisons. 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 Bonsai. 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.
Scale is the most common insect that attacks a Bonsai. Scale is usually identified by brown or black bumps on the branches. These bumps contain insects under a protective waxy shell. A very sticky secretion that discolors the branches may also be present.