| Golden Gate Ficus (Ficus microcarpa) Imported from China, 4 to 6 years old Tropical/Indoor Bonsai Care Climate Suited to bright, humid, equatorial climates, tropical bonsai prefer common room temperatures, between 65 and 75 degrees F, 3 to 4 hours of direct sunlight, and humidity levels of about 75%. If your home tends to be dry, a cool mist humidifier, tabletop fountain, or a ceramic bonsai humidity tray can help mimic the moist, tropical climate ideal for growing indoor bonsai. Placement Indoor bonsai are tropical plants adaptable to indoor conditions. Select a spot with good air circulation, but avoid cold drafts, drying heat vents, and appliances with heat exhausts. They prefer sunny areas, but avoid intense midday sun. If a tree is unhappy for some reason, it may loose its leaves (defoliate). This doesn’t mean it is dead. Make sure it has the right growing conditions, be patient, don’t overwater, and wait for a new set of leaves to come out. Your tree should spend the summer outdoors if possible, but be careful with the transition. Move it gradually from a partially shady spot into more sun. Ficus can withstand outdoor summer temperatures up to 100 degrees F as long as they are watered adequately. Bring bonsai indoors when night temperatures fall below 60 degrees F. Do not allow tropical bonsai to freeze. Watering Watering is perhaps the hardest thing to learn about bonsai. Bonsai are planted in very fast-draining soil mixes, so it is necessary to water them frequently. Water thoroughly until water flows out the drainage holes. Exactly how often you should water depends on the location of the plant and what growth stage it is in (more growth requires more water, slow growth periods will use less). Indoors it may be necessary to water only 2 or 3 time a week. The soil surface should be dry before re-watering. Do not over water! The soil should not remain soggy. Stick your finger or a chopstick into the dirt. It should be dry 1/3 to 1/2 way down the pot before you re-water. On the other hand, bonsai should never be allowed to dry out. Outside in the summer heat it is usually necessary to water daily, and maybe twice a day on the hottest days. Use a can with a rose or a hose attachment that won’t disturb the soil in the pot. Soil and fertilizer Bonsai spend years in a small amount of soil and eventually deplete the available nutrients. Providing supplemental nutrition is essential for a healthy tree. Most water soluble and time-released fertilizers work well, but commercial products like Miracle-Gro are generally used at half strength. Organic fertilizers with fewer harsh salts are available from bonsai retailers. Repotting In Minnesota, tropicals will generally need to be repotted every 1 to 2 years. Your tree needs repotting when you can see a lot of roots growing out of the bottom of the pot or when the soil gets compacted or shows a build-up of salts. Do not use regular potting soil. Information on soil mixes and repotting techniques is available in any basic bonsai book. Pre-mixed bonsai soil is available from many vendors. Check on line or call your local bonsai club for help. Members of the Minnesota Bonsai Society are eligible to attend our free monthly beginners’ classes for hands-on help with potting (and everything else you need to know to keep your trees alive and healthy). The ficus you are working on today will need repotting in about a year. Ficus are generally repotted during the hottest part of the summer, when they are growing vigorously. In Minnesota, that should be around mid-July. Training All bonsai require training. As the tree grows, trim the branches back to maintain the shape of the tree. Trimming encourages secondary branches to develop (ramification) and produces a more interesting tree. When new shoots develop on the trunk or branches, decide if they will add to the overall design of the tree. If not, remove them. Allowing the plant to grow unchecked changes the tree from a bonsai to a potted plant. Ficus will secrete a milky sap when they are cut. This is normal, and helps protect the tree. Rinse excess sap off the cuts with water, and use a good wound seal on any large cuts. Back to Home Page |