LED lighting for plant growth

Over the years I have grown my bonsai plants in windowsills, under incandescent light, fluorescent lighst or metal halide high intensity lighting. The best results up to now are clearly growing under metal halide lights. The downsides of metal halides are relative inefficiency with lots of heat released as a by-product and thus higher electrical bills as a result. Some years back I did use and test a commercial LED light in the early day of LED lighting that proved to be toxic to my plants. http://www.bonsaihunk.us/info/LEDvsFluoresc.html

Recently I purchased an LED light from ActiveGrow LED lighting. This is a 300Watt unit with about 180 individual LED lights. It replaced a 4 tube 4 foot long fluorescent light that was growing herbs for our daily consumption. The herbs are growing in a window box in a hydroponic growing system. On the left side remains one of the two original 4 tube fluro lights but on the right side I replaced the fluorescent with the ActiveGrow LED light fixture. Over the last 3-4 weeks the comparison of the growth of the plants on the LED side is 2-3 better than the old fluorescent left side. The growth is thicker, leaves more colorful and leaf texture much firmer indicating ideal growing conditions.

Herbs growing in a hydroponic growing system, right side LED and left side fluorescent lighting

I have to reconsider the use of LED lights for my plant room where I grow my bonsai and have had them growing that way for over 17 years.

Genetics and figs

These are two seed grown Ficus virens, Lipstick fig. Each plant shows some variation in its leaves, bark, growth pattern etc. These characteristics can be influenced by the growth environment. In the case of these two plants the newly emerged leaves are red in color. This color changes to a deep green after a week or two.

Since the two trees are grown in identical soil, identical lighting and identical fertilization the variation in the red color is due to genetics. One consistently has darker red new leaves. I would love to find a clone that has red leaves that remain red! That would be a great addition to the bonsai community.

The virens on the left has bronze colored new leaves while the one on the right has deep, dark red new leaves. Genetics of each is determining this factor.

Give it some time

Bonsai creation is not an instant or immediate process. Sometimes it just takes some time to evolve a suitable design. In this case a seed grown Ficus virens was a very un-attractive youngster. With a bit of patience and the passage of 5 years the tree is beginning to be an enjoyable bonsai. Given another 5 years it may even become outstanding.

Ficus virens 2017

Same tree 2012

Seed grown Ficus microcarpa, Clump style

I collected and sprouted a seed about 13 years ago that resulted in a plant that had low branches which I decided to keep as secondary trunks. The bonsai is what I would call Clump or Sprout style and is not that common in the bonsai world. It may be close to needing a nice container rather than its plastic development pot. Height is about 10 inches.

Ficus microcarpa, seed grown, in the sprout or clump style

One way to create a bonsai

There are many ways to shape raw material into a bonsai. In this case the bonsai was created from a Ficus rubiginosa cutting. At first it was allowed to grow long and healthy in a large container. It was then chopped down to a short segment and it was allowed to grow for several years. Next stage is to select branches and apex.

In the last stages it was moved to a smaller container to develop secondary branches and reduce leaf size. This process has taken 7 years but can be accomplished in a shorter time if grown outdoors in a tropical or sub-tropical area and kept in a large container or the ground until the refinement stage of development.

Even raw materials can be transformed into nice bonsai with this sequence of development.

Large healthy cutting of Ficus rubiginosa has been grown with no trimming to develop trunk size

The plant was chopped back(reduction cut) and allowed to sprout out. 

All new growth is allowed to grow to regain vigor. Tree is kept in a large development pot and not a small bonsai container during this phase.



Seven years after starting the cutting was beginning its transition to a bonsai. Further development will involve more secondary branches and leaf size control. Pot is about 8′ long.                                                                                                                                   


The definitive reference work on Ficus for bonsai. The book is a softcover, 8 by 10 inch volume, with 144 color pages, containing detailed information for the beginner as well as the advanced hobbyist. Click here for more information




Ficus ‘ExoticaJS’ and defoliation

This Ficus ‘ExoticaJS’ has been in training for only a few years from rough pre-bonsai stock. It is an excellent material for bonsai and it is not often available for sale.

Periodically I defoliate many of my bonsai figs. Doing this produces smaller leaves and makes the tree more showable. It also allows me to see defects or problems in the tree more easily than if leaves are covering the tree.

Ficus ‘ExoticaJS’ seen with all its leaves

After defoliation the structure of the tree can be seen and it is apparent that the right lowest branch needs thickening and more sub-branching while the left lowest branch is too thick and needs to be kept from growing too much

Fusing a fig tree

Using fusion to improve a fig tree is a valuable technique. However, it is necessary to use genetically identical material or the fusion my show differences in bark, leaf, etc. that can detract from the uniformity and believability of the design.

In this case seedlings of Ficus virens while very young were fused to create a sprout style tree. On careful examination of the trunks it is clear that they are not identical in bark character.

Ficus virens in a clump style created by fusion of seedling trees

Note that these three trunks do not look identical because genetically they are not the same

The base of your fig

One of the most attractive features of Ficus trees is their amazing, wide-spread surface rootage and the strong buttress of the base of the tree. This occurs more quickly when the tree is kept in relatively shallow containers. The fig responds by developing a very strong base and radiating powerful roots. However, care must be taken in shallow pots to keep the roots from rotting.

Ficus salicaria with powerful basal rootage and buttress base of the trunk

Ficus ingens, the Red Leaf Rock fig

Ficus ingens, the Red Leaf Rock fig, is an African species that is not very commonly used for bonsai. I have been working with several plants and do not find them the easiest species for leaf size control, and proper density of branching.

Here is one before defoliation with old, tired leaves. The appearance is quite messy and disorganized

The leaves are large, worn and old. So defoliation is undertaken.

Without the large leaves one gets a better view of the branching

After defoliation the appearance is much neater and looks more refined.

The new leaves will be red for a week or two after they grow in, giving it its common name.

Root-over-rock style

One of the most interesting styles of bonsai is the root-over-rock design. Simply a tree is designed to grow over a rock. There are many variations to this form but Ficus do very well in this configuration as their roots are aggressive and will cling to a stone if given a chance.

One caution is to use a normal form of a fig and not a dwarf form. The dwarf forms grow more slowly and it will take longer for them to anchor on the stone and to form good branching that will be needed to bring the design to life.

Ficus microcarpa ‘Taiwan Medium Leaf’ in a recent photo – more detailing and refinement of the branches is needed

Five years ago the tree was attached to the rock and it was buried deeply and allowed to grow freely

This is a Ficus microcarpa ‘Taiwan Medium Leaf’. It is one of the smaller microcarpa forms and is much slower growing. Initial work attached the tree to the stone and I buried the stone quite deeply. Growth was allowed with little trimming for several years to get the tree to stabilize and adhere to the rock. In later stages the branches and sub-branches will need to be defined to bring out the best in the bonsai.

The definitive reference work on Ficus
for bonsai. The book is a softcover, 8 by 10 inch volume, with 144 color pages, containing detailed information for the beginner as well as the advanced hobbyist.