WATERING – As the temperatures get warmer, the need for water will increase. However, continue to water only as needed in order to prevent root rot. Additionally, it is a good idea to water your plants early in the day so the leaves will be dry when going into the night hours thus decreasing the chance of any leave fungus.
FEEDING – Your bonsai plants should be full of new growth because of warm temperatures and longer daylight. As a result, the plants will need to be fertilized on a regular basis. There are many types of fertilizers, from synthetics to organics. Some examples are Ironite, Peters, fish emulsion, Osmocote, and Milorganite, just to name a few. Always read the application rate carefully and then cut the rate in half in order to avoid “burning” the roots of the plants with too much fertilizer. Additionally, don’t forget to alternate acid loving plants such as azalea and gardenia plants with an acid fertilizer. Also, you may want to alternate your flowering plants with a “Super Bloom” type of fertilizer.
WIRING – Plants are now actively growing and producing food, consequently the cambium layer will begin to thicken at a much faster rate. For that reason, continue to inspect the wire on all your trees to see when it’s time to remove it. Leaving the wire on the plant for too long will disfigure the branches; therefore, remove the wire if the branch remains in the desired position or if the wire is cutting into the cambium.
PESTS AND DISEASES – The activity of insects and diseases will continue to be on the rise this month as temperatures increases. Therefore, keep a close eye on your collection and look for anything unusual such as curly, stunted new growth; blotchy or spotted, white or pale yellow areas on the leaves; white, cottony patches; spots of brown on the leaves; and insect excrement. Use environmentally friendly treatments such as the encouragement of beneficial insects, spraying the plants with a hard stream of water, hand picking larger harmful insects, and/or the use of soaps and oils. Always remember to spray a small branch first in order to make sure there will be no phytotoxic* reaction to the plant from the soap and oil spray. An example of a plant that will drop all of its leaves if sprayed with soaps and oils is Fukien Tea. *Phytotoxicity is an adverse response in plants due to chemicals applied to the leaves or soil.
TRIMMING – Depending on the size of your collection, this will become a full time job! Always have a pair of scissors in your hand when inspecting your plants. After allowing the new growth to produce about four to six leaves cut it back to about two or three leaves. The result of continually trimming your tree will be twiggy branches thus producing a more refined bonsai.
PRUNING – Continue to do major pruning while trees are rapidly growing. The removal of large branches will encourage new, tender growth. Consequently, wounds heal faster because the plant is manufacturing more food and producing cambium at a faster rate.
LIGHT – Sunlight will begin to get more intense this month. For that reason, keep a close eye on your plants that are more sensitive to Florida’s harsh sun such as maples, azalea plants and shohin (small bonsai). Find a place for them that receives the less intense morning sun and that gets shade from the very intense afternoon sun. Maintain rotating your trees on a weekly basis, thus preventing them from becoming one sided.
TEMPERATURES – The temperatures are warm to hot. Keep a close eye on your plants. They will begin to dry out faster and some will not be able to tolerate Florida’s intense sunlight.
REPOTTING – Now that all your evergreens and deciduous trees have been repotted, it’s time to begin thinking about your tropical trees. Unlike deciduous and evergreens, tropical trees prefer to be repotted when they are actively producing new roots. Therefore, begin to prepare for repotting by making batches of soil and cleaning unused, dirty pots ahead of time. This will make the task of repotting go much faster and more enjoyable. When cleaning pots, use a water and bleach solution to disinfect pots and let them air dry. Also, do not to forget to cut up small pieces of screen to cover the drain holes. The end of April is probably a good time to begin repotting plants such as Fukien Teas and ficus trees. Avoid repotting buttonwoods till June.