Condensed and compiled by Les Lonsdale
1. “You must use composted pine bark, not fresh!”
Doesn’t fresh pine bark make nitrogen in the soil ‘unavailable’? Many bonsai nurseries have dispelled this myth. The ‘proof is in the pudding’, so to speak. There seems to be no appreciable differences in trees grown both ways.
2. “Always replace the inner root ball core during repotting.”
For yamadori or nursery plants this may be a good idea for the first repotting, especially for deciduous trees. You want to remove any clay or fine potting soil from the inner root ball. But, once the root ball is surrounded by bonsai media, the inner root core should not be disturbed, as it holds the lion’s share of fine feeder roots that lead to shorter internodes and smaller leaves.
As a tree matures, the soil used around the roots should become finer (less coarse). Coarse soil = coarse roots (fast, coarse top growth). Fine soil = finer roots (smaller leaves, shorter internodes).
3. “Sharp sand makes roots fork and increases ramification.”
False. The terminal point of a root contains a hard ‘cap’ which protects the root, keeping it from being damaged as it snakes it way through the soil. The splitting occurs further back on the lateral sides of the root. Water, oxygen, and nutrients cause root ramification, as well as root pruning.
4. “Always top-‐prune when repotting and root-‐pruning.”
Although one can get away with this when repotting most deciduous trees, this practice can be detrimental to conifers. Conifers do not store as much food in their roots as do deciduous trees. Instead, their energy stores come from the abundance of greenery. If some of that is removed at the same time as a lot of roots, recovery time can take much longer. Auxins, which encourage root growth are also found in the growing tips. Removing these tips will retard root growth as well.
5. “Repot after blooming.”
This technique works well in Japan where June is a wet/humid month, but if you live in part of the country with hot/arid Summers, it might not be such a good idea. It is best to repot in early Spring with the rest of the deciduous trees; then, one month later, fertilize with a low nitrogen/high phosphorus fertilizer in order to encourage blooms.
6. “Repotting in Fall is just as good as in Spring.”
This statement is only valid in warm climates where there are no hard freezes, or unless you can protect the new roots from freezing until Spring. Even then, trees are ‘programmed’ to grow in the Spring and rest in the Fall/Winter (except for tropical species). So, there will be a better success rate and faster recovery from repotting when performed in the Spring.
7. “The larger the pot, the faster the tree will grow.”
This statement is true only within limits. To get optimal growth out of juvenile trees, you should only double the size of the pot at the most. Any larger of a pot will create an undesirable environment for the roots of the developing tree. There will not be enough roots to absorb the water in the overly large pot, which will create a water-‐logged environment and limit air exchange. Also, the excess water will not encourage the roots to seek out water, therefore limiting ramification of the existing roots. During the hot summer months, the plant won’t have enough roots to supply the transpiration needed for the leaves. Gauge the up-‐pot to the tree; slow-‐growing trees need less up-‐potting than fast-‐ growing ones.
8. “Water droplets on leaves in the sun create burns, so don’t water in the heat of the day.”
This has been proven by science to be an ‘old wives’ tale’ with no truth to it. Optically, it is impossible as the focal length of an ellipsoid droplet is too long to hit the leaf. Watering in the heat of the day in the Summer can actually be beneficial as the evaporation of the water actually cools the leaves, soil, and pot.
9. “Temperate trees still need light in the Winter.”
This is not true. Some trees are covered with a snow blanket for much of the Winter. In true dormancy, there is no photosynthesis taking place, so light is optional. Of course, in warmer climates where some trees may not be in complete dormancy, light can still be beneficial.
10. “Trees from colder zones will not live in warmer zones due to a lack of winter dormancy.”
Although it is true that most fruiting trees need a certain amount of dormancy [at least 40 days below 40°F] in order to bloom/set fruit, this is not the reason that some trees cannot survive long when out of their growing zones. It has been found that the reason is actually the ‘day/night differential’ {DIF}.
If a temperate tree from a northern climate does not experience a DIF range of at least 20° during most of the year (that is, the nighttime temp. must drop at least 20 degrees below the daytime temperature and vice versa), the tree will begin to languish. Eventually, disease will over-‐take and the tree will die.
11. “Plant hardiness zone maps correspond to ‘root hardiness’.”
No, don’t be misled. The hardiness zone maps refer to the top of the tree, not the roots. It is assumed that the roots will be in the ground, therefore protected from excessively cold temperatures. We who grow our trees in pots need to be aware of ‘root hardiness’ zones also! There are charts available on the Internet, as well as on page 87 of this book.
NOTE added by Les (not in the book): The opposite is also true; that is, roots are not able to withstand very hot temperatures either. In the ground, it doesn’t matter how hot it is, the roots stay cool. Once in a pot, we become responsible for keeping the roots from over-‐heating. Plastic and mica pots do not present a problem, but clay/ceramic pots can get over 150°F when the Summer sun is on them. There are various ways to protect the pots from the sun (burlap, aluminum foil, placing pot behind another pot, shade cloth, etc). It may be a ‘hassle’ to go to the trouble of protecting ceramic pots during the Summer, but otherwise, you risk losing a valuable tree that you worked so hard to grow!
12. “Withholding fertilizer and water is the best way to keep leaves/needles short for all trees.”
Although this was an accepted method in Japan before better methods were discovered, this left trees weak and unhealthy. Now, this method is usually only applied to single-‐flush trees (Jap. Beech, White, Mugo, Scots, and Shore pines, etc) that cannot be de-‐candled or defoliated, in order to increase ramification and smaller leaves. On these type trees too much fertilizer/water will produce large leaves/needles so both are restricted.
For deciduous trees, the best methods for developing short internodes, smaller leaves is pinching, defoliation, and knowing when to delay fertilizer and when to apply it.
13. “If it’s a 2-‐needle pine we can de-‐candle it.”
This statement is only valid when referring to double-‐flush Japanese species (Jap. Black and Red pines). It is not true when referring to many European/N. American 2-‐needle pines which are single flush trees (Mugo, Shore, etc). These should not be de-‐candled. [The loblolly (3-‐needle) pine can be de-‐ candled].
Determine if your pine is a double-‐flush pine before de-‐candling.
14. “The right chemical will solve any problem.”
Although chemicals have their place, there are sometimes less-‐toxic techniques that can solve problems that chemicals cannot.
Plan A: Providing a tree with proper water, fertilizer, lighting, soil mix, etc. goes a long way in keeping it healthy. A healthy tree has built-‐in mechanisms/chemicals that help to fight off disease/pests, reducing the necessity of using artificial chemicals.
Plan B: Using water spray and/or mild soap mixes, or manually removing the pests, in order to avoid stronger chemicals. Keeping junipers misted daily keeps spider-‐mites from wanting to make a home.
Plan C: ‘Boxing technique’: This involves taking a sick/ailing tree out of its pot and placing it in a slightly oversized box with good drainage surrounded by pure pumice. Within a year or two the tree will usually be completely rejuvenated and ready for its show pot again.
15. “ Constantly pinch junipers.”
NO! The growing tips of junipers are the ‘engines’ of the tree. If they aren’t growing, the engine ‘stalls’. The proper way to style junipers is to shape them with wire and cut off branches that don’t fit the profile. Also, cut off ‘runners’ that quickly out-‐grow the other slower-‐growing foliage (unless you want a new branch there).
Learn the proper time of year for branch vs foliage pruning (branches: early Spring; foliage: Fall) Over time as pads eventually over-‐extend, cut back to shorter branches, but please, “Teacher, leave those tips alone!”
NOTE: Scale junipers are treated differently from needle junipers. For instance, needle junipers allow much more shoot cutting than scale junipers. Read up on the specifics for your particular type of juniper.
16. “To thicken the trunk, grow sacrifice branches low on the trunk.”
This is not the best way to thicken the trunk. 1st, it creates large, ugly scars on the trunk when the sacrifice branches are finally removed. 2nd, usually large accompanying roots grow under the soil below the sacrifice branch, and 3rd, usually the trunk only thickens on the side of the tree where the branch is, so growing the branch in the back (to hide the scar) defeats the purpose of the technique.
A better method is to grow the sacrifice branch at the top of the tree. When removed, the scar will be smaller and can usually be positioned in the back. The trunk thickens more uniformly as well as the roots.
17. “It is best to water on a schedule, in the morning or in the evening.”
People on busy schedules or on vacation may be able to get away with automatically-‐timed watering – for a while, but in the long run the trees will suffer. Trees with marginal root systems will get over-‐ watered, weakening the root system even more. Trees with a pot full of roots may suffer from under-‐ watering which can cause some root death, which can lead to root-‐rot. Also, automatic systems can fail at the worst times!
Different types of trees in different degrees of development have different watering needs. Accent plants and deciduous trees need more water than conifers. One waters best by observation; trees go through cycles of water needs depending on the seasons.
Also, without personally watering each tree you might miss important signals that the tree is sending such as not absorbing water into the pot, which might mean that there is a drainage problem.
NOTE: deciduous trees sign of under-‐watering = burned leaf edges pine tree sign of over-‐watering = burned needle tips
18. “Any water is good water.”
Not true. pH, as well as the hardness of water can affect the long-‐term health of your trees. Above a pH of 8 most plants cannot process and uptake several nutrients/elements. At a pH below 5.5 there will be calcium, phosphorus, and magnesium deficiencies. Chelated iron and/or sulfur can offset a high pH, but it is a slow, more long-‐term effect and not immediate.
The best way to lower the pH on a large watering scale is by using a siphon in a bucket of acidic water attached to a hose. The siphon measures out the acidic water at a fixed ratio, mixing it in with the hose water. On a smaller scale, white vinegar can be added to the water bucket. Another way is to collect rainwater which is usually at the correct pH.
Hard water is hard on plants, as it has excess Ca++ and Mg++ salts that hinder nutrient uptake. Leaves will be yellow and look washed-‐out. A hardness level > 150 needs to be dealt with, but don’t use a water-‐softening system as that adds sodium to the water. Better solutions would be an RO (reverse osmosis) system or rainwater.
19. “The more fertilizer the better!”
There is truth to the saying, “Too much of a good thing”. Too much phosphorus limits magnesium and iron uptake and can also limit mycorrhizae growth. Too strong of a fertilizer on mature trees can ruin the compact, short internodes, and small leaves. In short, you want young developing trees to grow fast and mature trees to grow slow. Pines have their own optimal fertilizer schedule. (see #22)
Too much fertilizer can also lead to pests and diseases, as the leaves will grow oversized and will be too thin, and lack sufficient defense mechanisms.
Too much organic mix in the soil can mimic over-fertilization due to the high CEC (cationic exchange capacity) which can retain and build-‐up fertilizer salts more than if using a volcanic media. Liquid chemical fertilizer applied at less frequent intervals are better for such high-‐organic soil mixes.
Larger, highly ramified trees need a more constant supply of fertilizer, but better if it is organic, and best if applied in tea bags. That way the tree gets a constant supply of low-‐dose fertilizer, and the amount can be adjusted easily by adding or taking away bags. Tea bags are also ideal for trees that will be publicly displayed, as the bags can be removed before showing, and then put back on later.
20. “Foliar feeding doesn’t work.”
Actually, it has been proven scientifically that most plants can absorb nutrients through their stomata, or cracks in the leaves. This technique is beneficial for trees with poor root systems or poor drainage or extreme pH, and good for slowing excessive salt build-‐up in the soil. Individual weak branches can be selectively foliar fed for balancing energy and growth. Trees with thick waxy leaves are the least likely to benefit from this type of feeding.
21. “Bonsai should be fertilized with 0-‐10-‐10 in the Fall; withhold the nitrogen!”
The fear is that nitrogen in the Fall will cause the tree to push new growth that might freeze before hardening off. However, studies have shown that trees need nitrogen in the Fall as well as in Spring and Summer. They pull it out of dying leaves and store it to help ensure a strong Spring flush. Also, once a tree begins to ‘shut down’ in the Fall, it will not put out new growth just because nitrogen is present.
The problem usually occurs if trees are hard-‐pruned too late in the growing season, too close to the first frost. Late growing-‐season pruning should be curtailed until after trees begin going into dormancy.
Nitrogen application can improve cold hardiness in conifers and helps them to come out of dormancy at a slower rate, thus reducing Spring frost damage.
The exception would be with tropical species that do not experience true dormancy. Late applications of nitrogen can push new growth which could be a problem if there are frosts/freezes.
22. “Fertilizing is easy, just broadcast it freely on everything!”
If this advice is followed in an effort to simplify things and fertilize all trees equally, eventually one will end up with a garden full of ‘wanna-‐be’ bonsai, either stunted and starving, or gangly and coarse.
Different types of trees need different concentrations of fertilizers at different times:
• Trees in training need more fertilizer and earlier in the Spring than do mature trees.
• Fat-‐trunk large trees need more fertilizer than do smaller thin-‐trunk trees.
• Black pines need more in Spring, none just before de-‐candling, and then more in the Fall.
• Maples, if fed too early will lose their delicate ramification and put forth thicker branches and huge leaves.
• Junipers need more; accent plants need less.
• ETC, ETC
This is why organic fertilizer cakes work well (or loose fertilizer in tea bags), as they can be added or taken off, and levels of fertilization can be adjusted easily. Liquid fertilizers from a watering can will suffice also, but more memory is involved in order to remember when you fertilized which trees.
23. “Stop fertilizing in the Summer!”
This statement is only valid in the hottest of climates where Summers reach > 95°F on a frequent basis. In that case, then yes, most temperate trees will enter a semi-‐dormancy state, so fertilizer would be wasted and could cause salt-‐buildup in the soil.
Otherwise, keep fertilizing your trees during the Summer, as long as you see that your trees are still putting out new growth.
24. “Vitamin B1 and other growth enhancers must be good.”
Vitamin B1 has been sold for over 80 years and touted as being excellent for preventing transplant shock, as well as being an excellent root stimulator, even though it was discredited and proven to be of no value as far back as 75 years ago. But ‘good advertising’ and traditions persist!
Superthrive has created two camps; those who swear by it and those who think that it is worthless.
Other ‘growth enhancers’ such as humic acid, seaweed, HB-‐101, silicon, and bio-‐char all have their mixed reviews with some negative and some positive results.
If one is willing to spend the extra $$ for these products, fine. However, good horticultural techniques and general fertilizers have done a good job without the use of these ‘snake oils’ for hundreds of years. You be the judge…
25. “Wound sealant is a waste of time – not needed.”
This is the current thought in some arboriculture circles these days due to Dr. Alex Shigo, a highly respected pathologist who gave this advice after studying the healing process of trees. His premise was that trees have their own defense mechanisms against pathogen invasion through compartmentalization. He believed that sealing a wound would actually trap pathogens and moisture inside the wound making matters worse. Though his premise was not ‘wrong’, it applies more to ‘yard’ trees rather than to bonsai trees.
Yard trees do not have to be aesthetically pleasing and die-‐back is not such an issue, but these are issues with our little trees. A sealant seals in moisture so that the cambium of the freshly cut area has a chance to callus properly without drying out and dying, which otherwise would cause die-‐back.
Also, there are some pathogens that can ‘outrun’ the compartmentalization process. Japanese maples, for instance, are especially vulnerable to Pseudomonas bacteria which enters through open wounds and can kill sections of branches/trunks.
Trunk/branch wounds should ideally be sterilized with alcohol or hydrogen peroxide before sealing.
Tools should also be sterilized before cutting on trees.
The slower a species is to heal a wound, the more important sealers are to fresh wounds (Ex. conifers, quince, ginko, azalea).
26. “Wires should always be wound at a 45° angle.”
Although this angle is ideal for brittle trees (azalea, holly, quince, boxwood, etc), it is not necessary for more limber species and especially for conifers. 60 – 70° wraps are just as efficient, and it saves on wire.
Mame and Shohin trees might be better wired at 45° since the branches can be so short, and apexes might be better wired at the traditional angle also, since they have shorter tighter bends. But the point is that this is not always the best angle.
27. “Moss prevents air and water penetration.”
To the contrary, moss has many benefits as a ground cover for bonsai:
• Enhances water penetration
• Assists in water-‐holding capacity near-surface, creating more root growth in the top layer of soil
• Insulation for surface roots from the hot sun as well as cold frosts.
• Helps prevent weed germination
• Minimizes soil erosion
• Aesthetic qualities
*Do not use much on pines as it may hold too much moisture in the soil.
*Clump-‐type is better than runner-‐type, which can climb trunks.
*Shredded moss can serve the same purposes.
28. ”Always 1st branch, 2nd branch, back branch!”
This guideline was created in order to ensure asymmetry and balance and was mainly developed for the Japanese black pine, but does not always translate to deciduous trees or other conifers. Forcing this formula can make a tree appear contrived, as can the traditional ‘S’ curve style.
Especially yamadori may not yield to such guidelines due to the pre-‐existing branch structure or lack there-‐of. Instead one should concentrate on creating a unique trunk-‐line and branch patterns that maintain the asymmetric balance intrinsic in good bonsai design.
29. “Never leave bar-‐branches!”
Although this principle should be generally followed, there are exceptions where it would be worse not to have them. Yes, in deciduous trees bar-‐branching can cause swelling and look too symmetrical, but sometimes, for instance, in mame and shohin trees the limited branching may call for bar-‐branches in order to complete the design.
In conifers they can be hidden and the pads from such branches positioned asymmetrically. Removing a bar branch just because of the ‘rule’ might destroy the balance of the tree design. Sometimes the resulting scar from removing a bar-‐branch might be worse than the appearance of the bar-‐branch itself. The Japanese seem more willing to leave bar branches than Americans. Once one knows the ‘rules’, one may bend them occasionally if it leads to an overall better composition.
30. “Avoid ‘pocket branches’ and ‘pigeon breasts’ as all times!”
True, they should be avoided, but not at all times. There are exceptions to nearly every ‘rule’ (see #29) and another ‘rule’ can trump – the rule of ‘balance’.
• Pocket branches – The tighter the bend in a trunk, the more important this guideline becomes. But sometimes, especially for yamadori or literati, a pocket branch may be needed for balance or density.
• Pigeon breasts -‐ Though frowned upon due to their ‘aggressive’ demeanor, there may be occasions where it is better to use that pigeon breast side as the front of the tree any way. When taking the ‘total package’ of the attributes of a tree into account (best nebari, trunk line, inclination, shari, uro, sabamiki, etc) here is another ‘rule’ that can be bent when needed.
Below is a list of other miscellaneous ‘rules’ that are not always true. Mr. Hagedorn gives good exceptions to each of these, although in general they are good rules to follow. If you want to know more, read the book:
Other rules/guidelines that have exceptions:
Pg 284 “Reverse taper should be avoided like the plague!”
Pg 287 “All wire must be removed before displaying a tree in a show!”
Pg 289 “Dwarf varieties are better.”
Pg 293 “Grafted trees are inferior bonsai.”
Pg 299 “More movement is more better.”
Pg 304 “A bonsai must have a thick trunk.”
Pg 308 “ Older is always better!”
