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Growing Begonias


Most begonias that one encounters are hybrids. These plants have usually been bred for some particular characteristic that the hybridizer liked, such as growing habit, leaf or flower color, or disease resistance. To grow these plants successfully, it helps understand the plants parentage, and more specifically, where the species originated.


In nature, begonias are found growing in the temperate zone around the globe. Central and South America, are very important sources of begonias, as are West Africa, India, South China, Malaysia, and Indonesia. It is well known that many begonia species grow in low lying, dense, heavily shaded jungles environments, usually near creeks and streams. Others occur high in tropical mountains, often near waterfalls. The major challenge for the hobby grower of these beautiful plants is to know the plant, itís background, and then to try to simulate the growing conditions that occur in nature for itís species parents.It is only when the correct conditions of light, temperature, humidity, soil, fertilizer, and water are met, will the plants grow healthy and flourish. We will examine each of the critical conditions as follows:


Light.Begonias are shade loving plants. The general rule is to never allow direct sun to shine on a begonia.There are exceptions of course. Many cane hybrids will benefit from early morning sunshine: some will even tolerate afternoon sunshine. Some thick-stem begonias will take mid day sun, but these are the exception.


Temperature.The ideal temperature range for most begonias is in the 62 to 72 degree F.Most will grow successfully, however, at temperatures normally found in the home, say from 50 to 85 degrees.Most will also tolerate drastically adverse temperatures, from a high of 100 degrees to a low of 28 degrees, for very short periods of time.My general rule is that a begonia plant will be comfortable in the same temperature conditions that I am comfortable in.


Humidity. Begonias like humidity.All of them like 50 per cent humidity as a minimum, and most like it even higher. Typically, if the grower supplies humidity of 60 to 80 per cert, the plants will grow successfully.There are some begonias, however, especially some species, that demand near 100 per cent humidity and thus can only be grown in a terrarium-like environment.Most growers supply humidity with misting, both in and out of greenhouses.In the home, placing the plant on a wet gravel bed will sometimes be quite successful.Some begonias will grow well in a kitchen or bathroom window ledge.


Potting Mix.††† One of the more important issues with begonias is not allowing the roots to smother in water.They must be allowed to get oxygen.To do this, the potting medium must be very loose and porous.There are as many potting mix formulas as there are potters, but the one that I personally find most useful is 50 percent peat moss and 50 percent perlite.This is very simple to make, and will work with all ages of all classifications of plants.Many mixes contain very course sand, some soil, and even vermiculite, but my experience says these components only get me into trouble.If the potting mix does not come with a wetting agent, just spray the mix with a mild, weak soap solution.Then the peat moss will wet properly.


Fertilizer.Begonias require periodic fertilizing, like any other potted plant.One fertilizing schedule that I find useful is to use a time-release fertilizer twice a year, January and April, and a soluble fertilizer at ľ strength weekly throughout the year.I use one teaspoon of a 16-8-12 time release formula, such as Osmocote, in a 6 inch pot, and a 15-30-15 soluble fertilizer such as Miracle-gro.


Water.The easiest way to kill a begonia is to over water it. The rhizome on some begonias, and the thickened stems on others, are water reservoirs and carry the plant through short dry periods. I recommend testing the potting mix one inch below the service for wetness with the finger, before any watering. Just stick your finger in, and if it feels wet, do not water. If it is dry, then water completely, till water runs out the bottom of the pot.Do not let the pot set in a tray of water at anytime.


Pots.I like clay pots for all my begonias.I like the feel of a heavy pot, and they donít blow over easy.A clay pot also dries out faster than one of plastic, hence it tends to correct any over watering. The one exception to this position is for hanging baskets.I use plastic 10 inch hanging baskets for many cane-like begonias and they do fine.Hanging baskets tend to quickly dry out, so again, they tend to correct any over watering.


If the grower will follow the above simple procedures, they can grow almost any begonia, with the exception of those requiring a contained atmosphere.Information on growing begonias in a terrarium will be covered elsewhere.