Fertilizers For African Violets

by Nancy Robitaille

Because most soil mixes have little nutritive value for African violets, we must rely on artificial means—fertilizers for basic feeding. But a look at the local nursery’s shelves  for fertilizers can be quite daunting to say the least.  Many growers swear by one or other of the popular named brands of fertilizers or even rely on homemade remedies such as left-over tea or Epsom salts to supplement the plant’s needs. Growing show plants is a different objective than just having pretty flowering African violets at the window or under lights. To make a healthier, more beautiful plant, fertilizer should be used. Which one? How much? Why change brands? Many questions come to mind when discussing this subject. No one formula or pattern for fertilization is the set one for everyone. Each person has his/her own environment which may be radically different from someone else’s. Therefore, let us just discuss what is available and what may be used, or tried by growers of African violets. When growing plants for show, certain procedures should be followed in order to have big, healthy, gloriously blooming plants. The question is: Where to begin? Following are some of the popular fertilizers used today by African violet growers. This is not to say there are not other brands or formulas that are as good, but this is just to list for those growers a program setup for healthy plants.

Some Popular Named Brands of Fertilizers:

• Peter’s 20-20-20
• Volkmann’s 15-30-15
• Rapid Gro 23-19-17
• Spectrum Earth Care 200-20 with iron and manganese
• Miracle Gro 15-30-15 with copper, iron, manganese, zinc
• Miracle Gro for Roses 18-24-16 with copper, iron, manganese, zinc
• Peter’s African Violet Special 1-6-14· Peter’s Variegated Violet Special 5-50-17
• Rapid Gro Blossom Booster 19-24-18 with iroon, copper, zinc, boron and manganese
• Volkmann Bros. 15-30-15
• Schultz

Oh, yes, there are many others which I have not mentioned. You know what the three numbers mean on each package of fertilizer -- proportional percentage numbers of Nitrogen, Phosphorus and Potassium. And that the first number, Nitrogen develops the foliage color, leaf and petiole growth. It also improves the quality of plant tissue and influences rapid growth. Protein content is also increased in the plant. The second number, phosphorus stimulates early root formation and growth which gives a head start to plants. This hastens maturity and stimulates buds to form. Potassium, the third number gives vigor and helps with resistance to disease. It is thought to improve reproductive quality. This is essential to formation and transfer of starches and sugars to the plant’s system.

A discussion of organic fertilizers is also necessary. It is not a good idea to use organic fertilizers in wicking plants since it plugs up capillaries which slows or even stops the capillary action. Also, some organic fertilizers have an intense fishy smell. So leaving it standing in a pot to be wicked up is not suitable. Here is a chance to use foliar feeding. Pay particular attention to the reaction of variegated plants when foliar feeding since this may cause leaves to “green up.”

Are you aware that foliar feeding is actually better for the plant than feeding it through its roots? Plants fed using foliar spray use 95% of the nutrients while root feeding uses much less. Reasonably, a foliar feeding should make a plant healthier than normal root feeding. Using the same fertilizer water (make sure it is at least room temperature if not warmer so spotting does not occur), mist the plant making sure every leaf is touched. Don’t worry too much about the center getting wet. If water accumulates there, use a kitchen paper towel or just blow on it to scatter the excess water.

Try a program balancing the fertilizers for the whole year. You might group all those fertilizers which are almost equal into one group and all the rest into another group, thus:

Peters 20-­20-20, Rapid Grow 23-19-17, Spectrum Earth Care 20-20-20 might go into the first group. While Miracle Gro 15-30-15, Miracle Gro for Roses 18-24-16, Peter’s African Violet Special 12-36-14, Peter’s Variegated Violet Special 5-50-17, Rapid Gro Blossom Booster 19-23-18, and Volkmann Bros. 15-30-15 would go into the second group.

Each of these fertilizers are used at the rate of ¼ teaspoon fertilizer to one gallon WARM water.

Starting with seedlings or new babies, use an even fertilizer from the first group for, say, three months, watering with fertilizer water APPROXIMATELY ever 7-10 days (each home environment is different and the rates at which water evaporates is different so plants may or may not always need more water at this time. You must test each plant.)

The three-month old baby plant may be making flowers by now. You can help it along by changing the group of fertilizers. (I would not recommend Peter’s Variegated Violet Special 5-50-17 until the very end of the year near the point of putting your plant in for show.) A month or two of this formula should produce a healthy plant while making those buds pop out proudly!

So now our baby is four, five, six months old and blooming well. Now is perhaps the time to consider Peter’s 12-36-14 for a few months. When switching fertilizers so frequently hopefully we are picking up trace elements found in some, but not all, fertilizers. At some point, I like to try the organic fishy fertilizers and these should be used sometime before show. As the show approaches, it will be time to try the heavier number fertilizers such as Peter’s Variegated Violet Special 5-50-17. I have never tried this on green plants and am curious to know what would happen. One thing is that the first number (5) is so little that leaves would be getting very little food.

Food for thought: You can definitely over fertilize and burn your plants so don’t take everything you read as gospel. Try any new procedure on one or two plants only. If this works, continue with the rest of your collection. Now, go get those blue ribbons!