http://ofbonsai.org/species-specific/tropical/willow-leaf-fig-ficus-salicifolia

The tree grows to about 15 feet in my area and will produce some aerial roots if the canopy is allowed to spread, the trunk will develop a buttress with nice surface roots, the bark is grey although it will become red if it is exposed to the sun. The leaves are alternate, lance late, although the new leaves are curved and tawny in color as they mature they straighten and develop a healthy green color. The green figs are small about .25″ turning a brick red with brown spots when ripe.
Growing Conditions

Our growing conditions in Vero Beach are subtropical, we get frost and occasionally we will have a hard freeze this usually lasts for one night. All of my bonsai are growing outdoors therefore it is necessary to cover them when we expect a freeze. Since my bonsai are growing on pedestals I have made a bag using agricultural winterization cloth that will fit over each plant, it is easy to put on and easy to remove.

Since Ficus Salicifolia is succulent it can go for long periods without water, if the plant is not watered in a reasonable time it will drop its leaves. It can live in this condition for a short time if it is healthy and in a humid environment. Ideally the plant should be watered thoroughly and the soil be allowed to approach dryness before the next watering. Any well draining bonsai soil is a good growing medium for this Ficus.

We do get a lot of rain in Summer which is not a problem if you use a well draining soil, since our Winters are dry, this can be good since the plants are not growing as much.

Most Ficus are not heavy feeders but they do respond to regular applications of a balanced fertilizer, if you use a liquid plant food it is important to apply it on a regular schedule during the entire growing season. A slow release formula that may last three months or more might be better for someone that does not have the time to maintain this strict schedule. Always follow the directions on the label.

They can be grown indoors if given the right environment. Light is usually the limiting factor but humidity, air circulation and temperature are just as important if you want to keep the plant healthy.
Propagation

All plants are started from cuttings you can use tip or cuttings as large as you have available. I start mine in perlite but any well draining soil will do, early spring has proved to be the best time to take cuttings. Large cuttings are started in 6″ pots and are allowed to grow in them until the following spring before transplanting to your normal soil. It takes about twelve weeks for them to root in my environment. If you are rooting them under mist it is important to have good air circulation to reduce the possibility of fungus.

Air layering is another method to propagate this plant, large caliper trunks can be used thus reducing the time required to produce an old looking bonsai.

Another method is used to create a group planting from a root cutting. When the root ball is cut from a large bonsai the roots that were removed will sprout if they are planted so that the top of the root ball is even with the soil surface. After the first year of growth remove any trunks that will not be needed for your forest, allow the trunks that will be your main trees to grow unchecked in order to develop a large caliper, the remaining trunks should be shortened accordingly to create a variety of sizes for your forest.
Insects and Diseases

Insects and diseases have not been a problem if the plant is healthy and good air circulation and light is provided. Over crowding is the usual cause of fungus, fungicides can be used as a preventive or if the plant is heavily infested leaf removal may be the best solution. If fungicides are used always follow the directions on the label.
Creating Bonsai

This plant can be used for any style but since it is an upright tree it is not normally used for cascades. It develops a trunk with a flared base and heavy surface roots. When cut back hard new buds appear over much of the trunk so that you have many choices for selecting branches. Aerial roots are a plus if you wish to create a banyan style, a humid environment and a large canopy of foliage will encourage their formation. The direction of the roots can be controlled by placing a split soda straw between the root and the soil as soon as the root appears.

It is important to split the straw its entire length so it can be removed after the root grows through the center of the straw into the soil.

When styling this tree you can be as drastic with your root pruning and top pruning as you wish to create the style you want, this plant is very forgiving, ideal material for the beginning bonsai artist. Wiring is only required for the initial styling after that the clip and grow method is usually used to develop the bonsai. Since the roots can be drastically reduced it is possible to plant the tree in a very shallow pot, which is very appropriate for a banyan style. Being able to drastically reduce the height of the plant it is possible to create a low ratio of tree height to trunk caliper. This bonsai is usually seen as a single trunk upright style, but it is ideal for group plantings, literati, driftwood etc.
Trunk

Start the styling by finding the front of the tree, first look at the trunk if it is straight any side could be used as the front, if it is slanted it could lean to the right or to left but never backwards. If the trunk is curved it is usually viewed from the side that shows the most interesting movement.

The length of the trunk is determined by several factors. A short tree will make the trunk look bigger and older than a tall tree with the same size caliper; a tall skinny tree looks juvenile. If the trunk is straight shorten it to the point where the taper stops, if the trunk is curved you may want to continue up the trunk until it becomes uninteresting.
Roots

Next remove the soil so that the surface roots are exposed, examine them from all sides pick the side with the most impressive roots and flare of the base, ideally the surface roots will be in proportion to the size of the trunk and will radiate out from the trunk. Choose the side with the most pleasing appearance.
Branches

The arrangement of the branches is sometimes determined by what is available. If your plant has a lot of branches to pick from, start by choosing your lowest branch, which should be on the right or left side. The second branch should be on the opposite side and slightly higher except on a banyan style, both branches should come slightly forward. Ideally a back branch will start between these two main branches. The other branches will revolve around the trunk and will become closer together as they near the apex. No branch should be allowed to grow directly above the one below it and no branch should be heavier than any one below it.

Wire all branches after you have selected the ones you want and adjust them to suit the style you have chosen. Be sure to remove the wires before they damage the bark, this may be as soon as a few weeks, depending on your growing conditions.
Potting

Pot your plant the same as any other bonsai keeping in mind that it is always possible to choose the correct size pot because you may reduce the root ball to fit any pot. Choosing the correct pot for your bonsai is very important. The pot should compliment the tree and be in proportion to the size of the tree. The length of the pot should be approximately two thirds to three fourths the height or width of the tree whichever is greater. The depth of the pot should be large enough to accommodate the roots the height should approximate the caliper of the trunk. Peculiarities of the specific tree may require you to deviate from these guidelines. The pot should always balance the tree; a massive looking tree will need a heavy looking pot while a younger looking tree will need a more delicate pot. Literate style is usually potted in a shallow round pot, banyan style looks good in shallow oval pots, blooming plants are enjoyed for their flowers therefore a glazed pot could be used to compliment the color of the flowers and cascades need a tall pot.

Make sure the plant is securely wired in the pot and always plant in dry well draining bonsai soil. Study the bonsai and make any adjustments you may need to make before you water it. It is not necessary to soak the soil immediately, in my humid environment I sometimes wait until the next day before drenching the soil.

It is important to give the bonsai proper aftercare, it should be placed in an area where it will get filtered sun and good air circulation the soil should be kept moist but not wet
Refinement

Refinement should start as soon as the plant is healthy and growing vigorously. First remove all the leaves and the unwanted branches, shorten the branches to fit in your silhouette. After new buds appear it will be necessary to remove all the unwanted buds that have sprouted on the trunk and branches, keep any new buds that are needed to complete the design. Rewire all primary and secondary branches that need to be repositioned. Study the design and remove any growth that is too long or is growing outside the silhouette, remove all terminal buds except those you wish to lengthen.

The next flush of growth will develop with smaller leaves and if pinching is continued on a regular schedule throughout the growing season the leaves will remain small. Pinching is the removal of the young tender growth at the end of each branch, it may be the terminal bud or it may be longer and include several leaves. The leaves on this plant are alternate and revolve around the stem. There is a bud at the base of each leaf, if we pinch back to a leaf that is growing on the side of a branch the new bud that sprouts will grow on that side. Therefore it is possible to direct the terminal growth of each branch in the direction we wish by pinching back to the leaf that is growing in the direction.

When pinching always keep in mind the shape you are trying to create and pinch accordingly. When looking at a branch from the top it should have a triangular appearance. The side view will have a flat bottom with no growth extending downwards, the top should be contoured so that the highest part should be closest to the trunk, and the end of the branch will taper to a point.

When working with mame bonsai we sometimes need to shorten a branch to a leaf that is not growing in the direction we desire. We can correct this by wiring the tip of the branch and twisting it in the direction you want the terminal bud to grow. The wire needs to be removed shortly after the new buds starts to grow.