Buttonwood bonsai care includes lots of sun and water.
Tropical hobbyists grow their Conocarpus in as much sun as each yard allows. Vigorous growth begins in spring and continues through mid-summer.
This plant likes water, however, when planted in heavy soil, fungus and/or root rot can become a problem! Coarse, fast draining soil is always best.
Safeguard all your tropical bonsai from frosts.
It may not kill them, but it will burn the leaves and you may have some residual damage such and dead branches.
If you have small buttonwood, bring them indoors when cold nights even threaten. Otherwise, place them under cover for protection. Even a cool night of 50 F (10 C) can cause a buttonwood bonsai to wilt, although it rarely causes damage.
Root pruning and timing of it are one of the most important parts of these buttonwood bonsai care notes.
CAUTION: Conocarpus roots are brittle at the point they connect to the trunk - and can break away easily. It is not unusual for a collected specimen to have very few primary roots (sometimes only one!)
There is often what looks like lots of root ramification. This can be a deceiving situation. Never ‘comb out’ buttonwood roots! Lightly hose off the old soil first ... to determine what’s really going on.
Timing is very important. The best time to repot and/or root prune this plant is during the season of warmest nights. But, don’t wait too long. Allow the tree recovery time.
In South Florida it's better to root prune this tree during May, June or July, not late August. The tree then has time to re-establish new roots before an early (although improbable) cool spell.
In more tropical climates (e.g. the Caribbean) timing root pruning is not a problem. Outside of those tropical regions, timing is a serious consideration.
During the winter months Conocarpus erectus has a natural “dormancy” period. As with many tropicals, this dormancy is not necessarily one with fallen leaves. However, the leaves can become unattractive during this interval. This is not the time to try to make it look better.
While the tree is resting, additional branches are forming. These buds will explode into the new growth of spring. This new growth causes old leaves to drop; it is a natural process.
Another ‘slow down’ period for your buttonwood is in the heat of summer. Again, it may not look 100%, but don’t encourage any special buttonwood care to make it better, let it rest.
As with any dead wood, watch for borers and termites. “Sawdust” may be the first sign. Old trees frequently have heavily textured bark ... good hiding places for damaging bugs. A wire brush is ideal for both the dead wood and cleaning the bark of buttonwood. At first, it may seem you are removing too much bark, probably not. You may be pleasantly surprised at the new color and texture exposed from the brushing.
Two pests which can be more annoying than harmful are the leaf-cutting bee and the citrus root weevil.
(Citrus root weevils are often called “greenies” because of their pastel green color.) Damage from both of these critters appears in the form of chewed leaves.
Moving your bonsai may be all that's needed to discourage the leaf-cutting bee. Removing the difficult-to-see, pastel green beetle by hand will best take care of him. Neither of these pests arrives en masse.
If you have mites, aphids or mealy bugs, the tree most likely needs more sun and/or better air circulation. Make sure your buttonwood bonsai care includes fertilizing on a regular basis. A healthy tree has fewer problems.
The leaves are particularly sensitive to chemicals … never use Malathion on this plant. If necessary, consider using a spray with a pyrethrin or soap base. For buttonwood, I have used and recommend both:Safer Brand Insect Killing Soap, 32 oz.
The jin and shari of Conocarpus erectus trees are very desirable as driftwood bonsai.
Conocarpus driftwood is very hard (at one time used for buttons).
The features can be enhanced by hard brushing and hand carving. They can even be created with power tools.
It is difficult to replicate the inherent beauty of driftwood, but it can be done.
Practice on throw-away pieces of wood first.
Dead wood on any bonsai requires maintenance. Buttonwood bonsai care is no exception. To prevent rot, brush it, keep it clean! Cleaning with a pressure cleaner is often the best way to get into the fine crevices.
These cleaners also remove loose bark and rotting decay.
To prevent rot, treat with lime sulfur. (Use lime sulfur outdoors; the smell resembles rotten eggs.) Lime sulfur is available from most bonsai dealers. To see instructions for applying, go to the National Arboretum page on applying lime sulfur.
Buttonwood bonsai care indoors can be a little tricky. When grown in low light (not its favorite location) buttonwood is highly susceptible to scale insects, mealybugs, mites, etiolation (lengthening of space on stems between leaves) and large leaves.
Rather than fight these problems continually, move the tree into high artificial light. Many growers have experienced good results with fluorescent lights.
Water with warmish water. Water straight from the tap in winter, may be too cold. Another helpful tip for other than tropical environments is: Use a propagation mat to keep the buttonwood’s feet warm.