What is the pH of your soils? (Videos)

What is the pH of your soils?

The pH is an indication of whether or not the soil is Acid, Neutral or Alkaline.

The soil  reaction and condition is measured in pH units.  When growing bonsai, you will need to be aware of this.  

What soil mix is acid and what is neutral?

Both are important for the health of the bonsai.  The pH also tells you what food is correct for the bonsai.  Azaleas are acid loving (Check our post about Azalea bonsai), while maples are not.  Some conifers prefer a slightly acid soil, while others like a slightly alkaline soil.  Some trees that grow near the sea have an alkaline soil, while some grow on a peat soil, which is very acid.  

The scale for the pH goes from 0 to 14, with a neutral point being pH 7.  The soil increases its acidity from pH 7 to 0, and increases its alkalinity from pH 7 to 14.  

In other words:

• A value of 7 is Neutral
• A value below 7.0 is acid
• slightly acid: 6.1-6.5
• moderately acid: 5.6-6.0
• very acid: 4.5-5.0
• A value above 7.0 is alkaline
• slightly alkaline: 7.4-7.8
• moderately alkaline: 7.9-8.4 (sea water is 8,2)
• strongly alkaline: 8.5-9.0
• very strongly alkaline: above 9.1

Making the right soil mix will depend on the tree's requirements and your local best practice.

A pH lower than 5.5 will mean that many nutrients become very soluble and are readily leached from the soil structure.  At higher pH levels, the nutrients become insoluble and plants cannot easily extract them.  The best take-up is a pH value of around 6.0 to 7.2

Akadama: It has a nominal pH of 6.8. Always sift the fines out and do not use them anywhere near your bonsai, especially as a top dressing, as they will wash in and compact the soil

Kanuma: It has a pH of 4.5 to 5.  It is used for acid-loving plants, such as azaleas, satsukis, ericas and stewartias.

Kiryu: The pH of Kiryu is around 6.8. You should use acid-based fertilizers on acid-loving plants to compensate its alakalinity.

How to take care of your Azalea Bonsai

Azalea are known for its bright pink blooms of stunning colors from bright red to pale pearl or red and white on the same bloom. It is commonly known as the "Royalty of the Garden". It is in Asia where it originated. The Buddhist monks cultivated Azaleas in different areas of Asia. Rhododendron which are Azalea Bonsai are probably the most common of the Bonsai Plants and there are many species to choose from. The nice thing about them is that they are very durable and pleasant to look at. Azalea Bonsai is one of the most popular bonsai in Japan and the Satsuki type is the chosen one among all the cultivar groups of azalea. The name Satsuki refers to the bloom period of the plant which is in the month of May to June (in accordance with the Asian lunar calendar) and they bloom later in the spring than other types, producing generous quantities of bright pink blossoms.

The Japanese believe in simplicity when it comes to aesthetics. And that is exactly what a tiny azalea bonsai reflects. Its culture is deeply rooted in the Asian culture and it adds not only a touch of class to your garden and home, but it also can provide a beautifully sedate focus for relaxation and meditation in your balcony.

The lovely thing about bonsai are that you can shape them in any style or design you desire. This is why it is an art. Although the Azalea can be used almost for all bonsai styles it is generally used for the root-over-rock, informal upright, slanting, semi-cascade style. Most bonsai artists will not shape one as a windswept or cascade style, as these do not reflect the natural growth habit of the Azalea. 

But we need to be aware that very few bonsai growers work with Azaleas because of the difficulty of keeping them healthy. There are, however, a few simple secrets that will allow just about anyone who is interested to grow a beautiful Azalea bonsai.

Azaleas come in roughly three varieties: Satsuki and Kurume, which are native to Japan, and the American Azalea, or Rhododendron, which is used extensively in landscaping in South America. The American varieties usually have larger leaves and flowers than the Japanese varieties. American Azaleas typically bloom in early spring. Satsuki and Kurume Azaleas typically have small leaves, which makes them better subjects for bonsai. 

The most common of the azalea bonsai tree to use is the Satsuki azalea bonsai. These types of flowers are by far the most popular in Japan to use as bonsai. The bonsai satsuki azalea is a hybrid that contains many distinct varieties of flowers within the species. They come in a wide variety of sizes and colors and often there are people that devote themselves to simply growing this species.

The Kurume azalea is also another species popular for use as a bonsai. It is a cross between the R kaempferi, R. obusum and R. kiusianum and has a wide range of colors with small funnel shaped flowers.

Unlike other Azaleas that bloom in early spring, the Chinzan can bloom frequently in late spring and summer, with many large 2″ salmon colored blooms. Satsuki Azaleas are known for their prized flowers and small evergreen leaves. Easy outdoor care.

Growing a bonsai from seed has its own merits. Most seeds will grow into plants inferior to the parents as the parents were selected from batches of hundreds of thousands of plants grown from seeds.  

Growing azalea from seed is a slow process at first. The good thing is that you can even create your own specie by the so called 'hybridizing'. By crossing two azaleas you can create many new azaleas that look different from both parents. Azalea and rhododendron seeds are very small as they are wind carried. The seedlings need special care. But they germinate well. An azalea will flower in 3 to 5 years when grown from seed. You can have something to put into a pot that will have one or more nice flowers in 5 or a bit more years. A real tree-like bonsai will take 10 more years. A big azalea will take 5 more. A big and old looking, add 10, 20 or more years. 

This is also why azalea or rhododendron seeds are often not available to be bought. 

Buying azalea nursery stock for bonsai is also often difficult. Especially if you want satsuki azalea, who have different flower aesthetics from western-bred azalea. In the west, different flowers on the same plant are an imperfection against which was selected strongly. 

Evergreen azaleas you can buy at almost all nurseries, but they are styled to be multi-trunk plants so they will make nice round bushes.

Satsuki azalea have several merits to them, but they are just another type of azalea cultivar. To me they are special because of the flower patterns.

In Europe, satsuki azalea are very rare. They are not used as garden plants and bonsai nurseries don't grow them themselves. They are all imported from Japan and importing cheaper smaller azalea is not worth the costs involved in importing. In the US we can have more luck as they grow well in the southern states close to the coasts (specially here in Miami). But strangely, in European countries with similar climates, they also don't seem available. Azalea should always be kept away from direct exposure to sunlight, especially in the summer season. It only needs partial sun. So it could be kept in a shade or a place which gets filtered sunlight. That is why it is a perfect option for your balcony. During the winter the tree should be protected from cold and chilly winds, ideally it should be placed in a greenhouse so that it gets shielded in a warm environment.

The type of soil to use for growing bonsai azaleas is one of the most important aspects of having a healthy plant. The soil needs to have good drainage, an acidic base of 5.0 to 6.0 and good ventilation. One way to accomplish this is to use a combination of 60 percent inorganic matter like perlite, sharp sand or Turface and 40 percent organic material such as pine bark or peat moss. Another good combination is to use 2 parts of peat moss, 2 parts of pine bark and 1 part of pumice.The soil mix used should not contain any small particles though, as it makes the watering of the plant difficult.

It is better to keep your Azalea in a damp soil, just damp enough to ensure that the plant is not in a drought condition. For this you need to monitor the soil and consider watering the plant whenever you find the soil to be dry. Just use your index finger to feel the moisture levels of the soil to determine if your bonsai needs watering. You should never let the soil completely dry out. If kept dry for too long, it could suffer serious damage. While watering you should always try to use natural water, using chlorinated water will result in the soil loosing its acidity and this could damage your bonsai.  If you need to use hard water, consider adding a teaspoon of vinegar to a gallon of water and using that once every month.  Make sure to water every other day during the summer hotter days and soak your Satsuki in a bucket of water for 10 minutes once a week.

For new azalea bonsai repotting should be donet every year, but once the plant gets old you could consider repotting it every two or three years. When repotting ensure, that you trim a third of the the root balls and any mats that have formed in the roots.  

Azalea should be pruned during the late summer (at the end of every flowering season) and wiring should be considered during the months of spring to summer.  You should be cautious while pruning the old branches as they are very delicate and easy to break off.  Do not trim the Azalea Bonsai tree until after flowering, then you remove all the dead flowers. Clip the branches according to your own design. Also place the wire loosely or not too tight so as not to hurt the wood.  

The Azalea is different from most plants used for bonsai. It grows most dominantly at the sides and base of the plant rather than at the top. So you need harder pruning at the bottom and sides. It responds well to being hard pruned and cut back to a stump after flowering. Do not do this two years in a row.  You should use aluminum wire instead of your traditional copper wire to shape your azalea bonsai because azaleas have brittle branches that can snap if you’re too aggressive with your wiring.

The azaleas need fertilizer but not while they have flowers. Begin in spring and do it every two weeks until you notice the buds. If you fertilize while the plant flowers, you will lose both flowers and buds. After the flowering begin the regime of fertilizing again but only do it once every month. Since this is an acid loving plant, use the fertilizer appropriate for that type of plant. Try to feed it with organic fertilizers.You could also consider using chemical fertilizers; generally you should use a half strength solution of any good Bonsai Fertilizer available at your local store. While using chemical fertilizers you should consider feeding the plant fortnightly.

Several pests like the azalea; like the caterpillars, aphids, scale insects and white flies. Remember that if you spray open flowers with a pesticide, they’ll wilt and fall. While you can use pesticides or insecticides to get rid of these pests, there is actually a more natural way to get rid of bugs without having to use pesticides. (For example you can use this home made Garlic Tea Spray by boiling a pint of water, throw in roughly chopped garlic cloves and steep until the water cools. Remove the garlic bits then spray).

I hope you have liked this post. Please leave your comment and let us know how we can improve our blog.

Tips & Care: How to fertilize your orchids

In the rainforest, the  orchids get their nutrients from water that runs down the  tree and in between the bark by way of the roots that are attached to the bark. Most of it is fine organic material comes from the parts of the tree of from animal feces washed off of the tree by rain. But in reality, they  make their own food by combining water with carbon dioxide  and the energy they derive from sunlight through a process known as photosynthesis. 


Unfortunately, This would be very difficult to mimic at home. You can use fertilizer to overcome these problems. But orchids require only moderate amounts of fertilizer to naturally grow well.  On the other hand, if you try to speed their growth by fertilizing orchids more than they should, there’s a high chance that the plant’s health will suffer due to the extra chemicals.  The leaf tips will become brown from the excess sodium, and the roots will burn and shrivel.


A good schedule is the commonly known as "a weak weekly approach" to fertilizing orchids. In this case you would follow the instructions from the manufacturer (because the concentration of nutrients vary from one to the other) but I recommend for you to make the solution at quarter strength. The fourth time you are "supposed" to fertilize,  skip it in order to keep the minerals from the fertilizer from building up on the potting medium. You can flush your plant with clean water at least once a month.  Even if you fertilize your orchids lightly, skipping this step will cause salt deposits to build up in the soil and burn the roots.  It will be as if you had over-fertilized your orchids.During the winter or cool months when the plant is resting fertilize half of what you have been doing during the growing season. Water often enough so the plant does not completely dry out. Mist the leaves every other morning if you are using the heating, do not forget that the micro climate can get too dry for the orchids, and they don't like it. 

The new orchid enthusiast may be initially overwhelmed by the many kinds of available fertilizers. Some stimulate growth, others improve blooming, and there are those with extra magnesium, iron, calcium, etc. Despite all these options, fertilizing orchids is a fairly straightforward process, and most orchids (even hybrids) thrive beautifully with a simple fertilizing program.

Any commercial fertilizer should ideally contain,  roughly seventeen distinct elements, divided into Macro and Micro nutrients, where the macro nutrients are: Nitrogen (N), Phosphorus (P) and Potassium (K). Although they are needed in smaller proportions, orchid plants also need micro elements such as Calcium (Ca), Iron (Fe), Copper (Cu), and Zinc (Z). And in even small quantities, orchids need a wide variety of trace elements.

A good orchid fertilizer should have all of the elements I listed above and a commercially packaged fertilizer will denote the percentage of its macro elements in the following order: Nitrogen (N), Phosphorus (P) and Potassium (K). For example, if the label reads 15-23-40 if means that the said product contains 15% Nitrogen (N) plus 23% Potassium or Phosphates (K) plus 40% Potassium or Potash (K).

Do you know what each macro nutrients is for?...Gladly I will tell you really quick about them. 

First, Nitrogen is the macro element that paints the orchid leaves in their deep green color as it promotes their growth and is also needed for the growth of the stem that will carry the orchid’s magnificent bloom.

Phosphorous is the macro element that promotes the development and growth of the orchid plant’s root system and its breathtakingly beautiful and eye catching flowers.

Potassium is the macro element that is instrumental in building the orchid’s tissues and helps it produce the chlorophyll without which it cannot survive.

If you would like to get more technical and thorough about fertilizing orchids, you may invest in a pH meter.  This instrument is based upon the fact that orchids can only absorb nutrients if the fertilizer mix is within a proper pH range.  

This range is generally 6 or 7 for acidic orchids.  Fertilizer is normally acidic, but the pH level can drop to 6 and below when mixed with pure water.  If your orchid’s growing medium is acidic due to peat, spaghnum moss, or decaying organic matter, this low pH level may interfere with nutrient uptake.   This won’t be a problem if you use water with high mineral content, making the pH level alkaline. When mixed with fertilizer, the naturally occurring minerals in water will balance the pH level out to the optimal level of 6 or 7. However, you can only be sure by testing it, and this is where you’ll find the pH meter handy.

Fertilize your orchids 2-3 times a month during the warmer months (easier for me is to do it every other Sunday morning) and 1-2 times per month during the winter when growth is slower. Unless you are using rain, or reverse osmosis water that is very pure, you should  flush your plants thoroughly with water at least once a month to get rid of excess salts.

Orchids potted in a bark mix, use an orchid fertilizer with a higher nitrogen content (such as 30-10-10) or a 'urea-free' formulation. For those plants in a peat-based mix, or sphagnum moss, a  balanced 20-20-20 formulation or 20-10-20 is fine(see box for more information).

In both cases, switch to a 'blossom inducing' fertilizer (such as 10-20-10) once new leaves have matured, generally in the later summer and continue to use this during flowering.  Alternatively, switch between fertilizers each time you feed.

I hope you found this post interesting enough to start practicing your fertilizing technique.
So, remember how to read the labels, compare them one to the other depending on your orchids needs, specially on the season you are, and then...do not overexpose the orchids to it...just do it regularly with a low strength each time and you will get beautiful blooming season this coming spring/summer.