HOW TO GROW AND CARE FOR OUR PLANTS
African violets are among the best known houseplants for their lively flowers present at all times of the year and also because cultivating them is not complicated as long as the necessary growing conditions are ensured.
Species: see the paragraph on "Main species"
The kind Saintpaulia, better known as African violet, belongs to the family of Gesneriaceae ed it is original of Tanzania (East Africa) and in the forests of Uzunga there are 18 of the 20 known species. Some of these species are cultivated with great success as houseplants because they bloom all year round, as long as the necessary growing conditions are ensured.
African violets have a root system shallow and for this reason they grow well in small pots and bowls. A short stem develops from the root system from which the leaves branch out in a rosette.
Leaves they are more or less rounded or heart-shaped, are dark green, more or less intense and have a velvety appearance as they are covered, on the upper page, by a thick and thin down.
The flower stems grow from the axil of the leaves, forming an inflorescence with few flowers, single or even double (especially in the cultivars), with five star-shaped petals, with colors ranging from white to blue, red and violet passing through a whole range intermediate of shades.
The size of African violets is variable. There are cultivars that require a 20 cm pot, others such as 10 cm mini pots and still other pots of only 4 cm.
There are numerous species (and many more cultivars) in the genus Saintpaulia among which we remember:
There Saintpaulia jonantha it is the best known species and most of the cultivars and hybrids on the market have been obtained from it.
It is a perennial stemless species that forms dense rosettes of ovate-shaped leaves carried by long petioles. The flowers are blue-purple in color, with small pollen sacs of intense yellow color placed in the center of the flower.
There are many cultivars on the market that differ from each other for the size of the plant; the color, shape and size of the flowers.
SAINTPAULIA CONFUSA or SAINTPAULIA DIPLOTRICHA
There Confused Saintpaulia it has lighter green leaves with jagged edges and light purple flowers with dark edges.
There Saintpaulia grotei it is a drooping species, therefore it lends itself well to being cultivated in hanging baskets.It has stems up to 40 cm long which root at the nodes. The leaves are up to 8 cm long, have prominent ventures and are carried by petioles up to 25 cm. The flowers are pale mauve with a violet throat.
There are numerous hanging hybrids that are found on the market and all derive from this plant.
AFRICAN VIOLET CULTURAL TECHNIQUE
In nature, African violets are undergrowth plants therefore they should be cultivated at a light intensity of 8000 - 10,000 lux, therefore not too much light and should never be exposed to direct sunlight. Violet loves more than light intensity, a very prolonged exposure to light. In fact, it can also be grown very well in artificial light by placing the plant under 40 watt fluorescent tubes for about 12 hours a day.
Beware of air currents that are in no way welcome.
Saintpaulia blooms when temperatures remain around 18-25 ° C. During the winter, temperatures must not drop below 15 ° C.
In the spring-summer period it is good to water the African violets often, while in autumn-winter they must be thinned out. Between one watering and another, the surface layer of the soil must be allowed to dry completely.
To water them correctly it is necessary to use non-limestone water at room temperature; moreover it is advisable that the water is given from below, placing the vase in a low container full of water for the time necessary for the plant to absorb the water it needs. After that, when the ground is well wet, any excess water is allowed to drain.
Do not wet the leaves otherwise they get stained and could easily be preyed upon by mold.
The Saintpaulia they like a humid environment. To create it, you can place the vase on a saucer you will have to place some expanded clay where there will be a constant stream of water which evaporating will guarantee a humid environment for your African violet. Be careful that the vase is not in direct contact with water.
TYPE OF SOIL - REPOT
There Saintpaulia it is repotted only when the roots no longer have space available in the jar. Repotting should be done in spring.
Do not use too large pots (maximum 20 cm) using a good peat-based soil so that the pH of the soil is slightly acidic mixed with coarse sand to help water drainage.
FERTILIZING AFRICAN VIOLET
There Saintpaulia has high nutritional needs above all nitrogen, phosphorus and potassium for which it rapidly consumes the natural endowment of the soil on which it grows; for this reason, if we want it to develop harmoniously and produce abundant flowers, we must give it liquid fertilizer every three weeks, together with irrigation water.
In winter, once a month is enough.
Use a good fertilizer that in addition to having the so-called macroelements such as nitrogen (N), phosphorus (P) and potassium (K), which also has microelements such as iron (Fe), manganese (Mn), copper (Cu), zinc (Zn), boron (B), molybdenum (Mo), all important for a correct and balanced growth of the plant.
A tip: slightly reduce the doses compared to those reported in the package.
The African violet produces flowers practically all year round. It blooms when temperatures remain constant around 18-25 ° C.
The African violet is usually pruned. The leaves that gradually dry up must simply be eliminated to prevent them from becoming a vehicle for parasitic diseases.
Make sure that the tool you use for cutting is clean and disinfected (preferably with a flame) to avoid infecting the tissues.
AFRICAN VIOLET MULTIPLICATION
The genre Saintpaulia propagates by leaf cutting or for immersion of a leaf in water
MULTIPLICATION FOR THIS FOLIAR
In late spring (May-June) a leaf with the whole petiole is taken. Take care to take a whole leaf, healthy and that has recently finished growing (in practice neither too young nor too old).
The petiole is cut for a length of 3-4 cm from the attack of the leaf. It is recommended to cut with a razor blade or a sharp knife to avoid fraying of the fabrics. Make sure that the tool you will use for cutting is clean and disinfected to avoid infecting the tissues.
It is preferable to dust the cut part of the leaf with a rhizogenic powder to favor rooting.
Then arrange the leaves in a soil consisting of peat and sand in equal parts so that the pH is around 5. Make some holes with a pencil, as many as there are lethal and foliar and arrange them as shown in the photo. Then take care to gently compact the soil around the petiole.
The box is then covered with a transparent plastic sheet (or a hooded bag) and placed in the shade and warm for about six weeks, taking care to keep the soil always slightly moist (always water without wetting the rooted leaves with water to ambient temperature and not calcareous).
Once the first shoots begin to appear, the plastic is removed periodically and for longer and longer periods for about a month. Also start giving a little fertilizer with the irrigation water, once a week with a high nitrogen content to favor the growth of the plant.
After about two and a half months since you planted lethal, take the single African violet seedlings with delicacy and settle in the final pots and treat them as adult plants.
Take care at the time of repotting not to bury the new plant excessively because it is more easily subject to bitters, nor to put it too raised because otherwise the form that the adult plant will take will not be compact.
MULTIPLICATION BY IMMERSION OF A LEAF IN AFRICAN VIOLET WATER
You can immerse the leaf with the stem in a glass of water.
In practice, you take a glass of water that you will fill almost to the brim and you will place a piece of aluminum on it.In the aluminum you will make as many holes as there are leaves and in each hole arrange the petioles of the leaves so that they reach the water.
When the roots and buds begin to sprout, wait until the seedlings are about 2.5-3cm long (about a month after you started). At this point, take every single African violet plant and place it in its final pot using a predominantly peaty and non-calcareous soil and treat it as an adult plant.
PARASITES AND DISEASES OF THE AFRICAN VIOLET
If their needs are respected, African violets grow well and have no particular problems. Generally all the problems of the Saintpaulia are caused by bad cultivation techniques.
Leaves with yellow spots
The damage can be caused by watering with water that is too cold on too hot days or too low temperatures at night.
Remedies: take action accordingly.
The plant remains small, few flowers are formed, and the leaf petioles do not stretch
This is the classic symptom of excessive light.
Remedies: place the plant in a more shady place.
Fall of the shoots
There are several causes that can cause the sprouts to fall, including too low a temperature and humidity, an excessive amount of irrigation water and sudden changes in temperature.
Remedies: take action accordingly.
Leaves shriveled and yellowed with consequent withering
This damage is caused by insufficient watering and too low atmospheric humidity.
Presence of root and basal rot
Rot is a classic symptom of a parasitic attack caused by a fungus, Phytophtora spp. and Pythium spp. Violet affected by this disease manifests dwarfism, wilting and extensive root rot. The attack is favored by excessive humidity.
Remedies: in this case it is necessary to dry the soil from the excess water and allow the surface soil to dry and treat the plant with specific fungicides.
Presence of gray mold on the leaves
This damage is caused by a fungus, Botritys spp. which is favored by too high humidity.
Remedies: it is necessary to eliminate the damaged parts immediately, allow the soil to dry up from excess water and treat with specific fungicides. For the future, keep a less humid environment around the plant.
Spots on the underside of the leaves
Spots on the underside of the leaves could mean that you are in the presence of cochineal and in particular mealy cochineal. To be sure, it is recommended that you make use of a magnifying glass and observe yourself. Compare it with the photo on the side. They are features, you can't go wrong. Also if you try to remove them with a fingernail, they come off easily.
Remedies: remove them with a cotton swab soaked in alcohol or if the plant is large and potted, you can wash it with water and neutral soap, rubbing very gently with a sponge to remove the parasites, after which the plant is varisced very well to eliminate all the soap. For larger plants planted outdoors, you can use specific pesticides available from a good nurseryman.
Presence of small whitish animals on the plant
If you notice small white-yellowish-greenish mobile insects you are almost certainly in the presence of aphids or as they are commonly called lice.Observe them with a magnifying glass and compare them with the photo on the side, they are unmistakable, you can't go wrong.
Remedies: treat the plant with specific pesticides readily available from a good nurseryman.
The kind Saintpaulia it was dedicated to Baron Walter vonSaint Paul-Illaire (1860-1910) who discovered it in tropical eastern Africa (Tanzania). The first species classified by the naturalist H. Wendland was named jonantha which means "with flowers similar to violet" and this explains why this plant is commonly called African violet.