The duration and intensity of light play an important role in the life cycle of the African violet. As a rule, the best place to place indoor flowers is a windowsill, but this is not exactly what is suitable for violets.
In summer they need protection from overheating, in winter from the adverse effects of hot and dry air from the batteries.
Next, we will tell you in detail about African violet light requirements, what the violet loves light or shadow since the right lighting will allow the plant to actively grow and bloom almost all year round.
Natural vs articfical light African violet
First, let’s see if violets like sunlight. In nature, the violet grows in warm climates with a predominance of clear sunny days. Being under the forest canopy, it is illuminated by diffused light with partial dimming.
In nature, violets are not exposed to direct sunlight.
Important! The optimal illumination of violets is soft diffused or shaded light for 10-13 hours.
Despite the fact that Saintpaulia belongs to shade-tolerant plants, with a day of light less than 8 hours it stops developing, which can cause its death.
If violet is provided with good natural light or compensated for its lack with an artificial light source, then it can be grown in any part of the room. Improper lighting is one of the main mistakes when caring for violets:
- the flower does not like the scorching and bright sun , therefore, it is better to cover the shelf or stand for Saintpaulias with a thick light curtain;
- if the window is directed to the south, then it is better to place the violet in the corner or in the back of the room;
- sills of northern or eastern windows are optimal for cultivation .
No less unfavorable for the development of violets is the short daylight hours (less than 8 hours) and the weak intensity of the rays in winter. At this time, the plant needs photo lamp illumination.
Here is the answer When To Transplant African Violets?
do african violets need direct sunlight?
Knowing whether violets love the sun, when cultivating them in a temperate climatic zone in natural light conditions, it is necessary to take into account the time of year:
- from October to March – it is permissible to keep a violet in direct sunlight all daylight hours;
- from May to September – in the interval from 10 am to 4 pm, direct sunlight shades 60-70%, and up to 10 am in the morning, as well as after 4 pm, cultivation in direct sunlight is permissible;
- if the weather is cloudy, the plant does not need shading.
In cloudy weather, violets can not be shaded.
Speaking about whether violets like direct sunlight, it is worth noting that varieties with dark leaves are more resistant to bright light, they can be placed on window sills closer to the glass, and on shelves – in the center of the lamp.
Since violets have a rather capricious attitude to light when they are grown on a windowsill without backlighting, it is recommended to place them in the following order:
- 1st row from the window – varieties of violets with dark green foliage;
- 2nd row – with straight leaves of medium green color and wavy dark green;
- 3rd row – with wavy light green leaves and a very pubescent leaf blade, for the growth of which strong shading is necessary.
Thus, you can select varieties of violets for light, as well as dimly lit windows.
do african violets like artificial light?
Natural light is optimal for the full bloom of the violet. But in conditions of its lack in the autumn-winter period, the plants must be supplemented with artificial lamps.
This combination provides:
- a spectrum as close to natural as possible, necessary for the good development of violets and bright color of the petals;
- the duration of daylight hours necessary for the setting and flowering of buds.
In the autumn-winter period, inexpensive fluorescent lamps are suitable for additional illumination of violets, their spectrum, in this case, is not decisive:
- fluorescent lamps evenly distribute light over a larger area than other types of lamps;
- they are installed at a distance of 20 cm from the top of the bush.
Usually, the lamps are placed slightly higher and then using stands to adjust the height of the plants.
Violets that are located on the windowsill or next to the window are best illuminated with an LED strip:
- the tape should have a white cold color with a power of 15 – 25 watts per m2;
- the power depends on the location of the window relative to the cardinal points and shading by trees or buildings;
- the turn-on time of the LED strips is regulated by a timer.
If it is not possible to grow Saintpaulias in natural light, artificial lighting will come to the rescue.
Can African violets survive in artificial light?
In conditions of artificial lighting, violets grow and develop beautifully, thanks to this:
- Saintpaulia can be propagated by leaves all year round ;
- place large collections regardless of the location of the windows and the area of the shelves.
When installing artificial lighting, it must be borne in mind that the process of photosynthesis requires blue and red spectrum.
The following requirements are imposed on artificial lighting of violets :
- During the period of peduncle formation, the duration of illumination is increased from 10 to 12-14 hours, or the intensity of light is increased, including not one, but several lamps, or the violet is raised closer to the lamp;
- In order not to cause a leaf burn, the duration of daylight hours is increased gradually, adding 30 minutes every two days;
- The time of switching on the lamps is important for plants: it is preferable to do this every day at the same time.
To regulate lighting, a mechanical or electronic timer is used, which turns on and off at the right time.
See also Methods for Propagating African Violets.
growing african violets under lights Setup Guide
To properly organize artificial lighting, pots with violets are placed on shelves or racks.
Types of light for african violets
Conventional incandescent bulbs are not suitable for growing violets:
- they have an unsuitable radiation spectrum;
- low efficiency;
- emit a lot of heat, destructive to the flower.
Illumination with incandescent lamps is unacceptable because they can cause burns.
The light source is usually linear fluorescent lamps, which come in white, cool white, and warm white spectra. They are made in the form of tubes with a diameter of 26 mm and differ in length, which correlates with the power:
- a lamp with a length of 60 cm corresponds to a power of 18 W;
- 90 cm long – 30 W;
- 120 cm long – 36 W;
- length 150 cm – 54 W.
The size of the luminaire and its power is selected based on the area of the illuminated place. When choosing a lamp, it must be borne in mind that:
- the shorter the lamp, the less it will last (the service life of an 18 W lamp is about six months, and a 36 W lamp is almost a year). After this period, the luminous flux weakens, although visually it is not noticeable;
- The luminous flux produced by two 18W lamps is less intense than from one 36W.
Fluorescent lamps are filled with small amounts of mercury. As long as the lamp is intact, its use is completely safe.
Carefully! A broken fluorescent lamp is dangerous to your health, it should be disposed of at special collection points.
LED strips are also effective. Their main advantage over other lamps:
- high energy efficiency;
- ease of attachment to any surface and in any position.
The downside is the rather high cost.
how much light does an African violet need?
Distance to outlet leaves, the maximum number of switching hours per day.
Lamps are fixed on shelves according to certain rules:
- the spacing between the shelves is determined by the gap from the light source to the leaves of the flower;
- shelves for standard varieties of violets are placed at intervals of 40-50 cm, while the distance of the lamp from the bush should be 30-35 cm;
- for mini-varieties of violets, they maintain an interval between the shelves of 25-30 cm.
In this case, it is necessary to take into account the height of the pot and the design of the lamp. For example, with a pot height of 10 – 12 cm and a lamp thickness of 7 cm, the gap between the shelves is about 45 cm.
When installing LED strips, the distance between the shelves will turn out to be much less about 25 cm.
The most comfortable light regime for violets is 12 hours of lighting, 12 hours of darkness. If the plants show that there is not enough light, the lighting period can be increased to 15 hours per day. If this does not help, you will have to change the design of the rack: reduce the gap between the lamp and the flower, or hang another lamp.
Calculation of lamp power
When planning shelves for violets, you should focus on the size of a standard lamp:
- for shelves with a length of 70 cm, 18 W lamps are installed;
- for 130 cm shelves – 36 W lamps.
The number of lamps also correlates with the width of the shelves:
- one lamp provides the necessary illumination of a shelf with a width of about 30 cm;
- two lamps – shelves 50 cm wide.
When calculating lighting for violets, it must be borne in mind that:
- per 1 cm2 of the shelf area, the light flux from fluorescent lamps should be 0.7-0.9 Lumen;
- per 1 cm2 of shelf area, the light flux from LED lamps or tape should be 0.22-0.44 lumens.
Based on this, a shelf measuring 96×38 cm (area 3650 cm2) must provide a light flow:
- produced by fluorescent lamps – 2550-3280 Lumens;
- produced by LEDs (lamp or tape) – 800-1600 Lumens.
The optimal light flux is considered, which is closest to the maximum (1300 – 1700 Lumens per shelf). For example, for a shelf of 100×38 cm, the luminous flux should be 840-1680 Lumens.
Advice! The temperature on the upper shelves is always slightly higher than on the lower ones, so it is better to place young plants on them.
Here is our best step-by-step guide on Making Wick Watering System For African Violets.
how light affect growth of african violets?
Do the violets need light, they themselves will tell you with their appearance:
- if young leaves develop well, and the peduncles rise up above the outlet, then the violet has enough light;
- elongated petioles, too thin a leaf blade, the leaves are directed upward , the violet stops growing and blooming a sign of insufficient light;
With a lack of light, the leaves begin to stretch.
- in good light, the leaves of variegated varieties are brightly colored;
- leaves go down , beyond the edges of the container, the color is light, with yellowness, the petioles are shortened, the rosette is thickened – long daylight hours (more than 14 hours);
- short peduncles, pale color and shrinking flowers, short flowering period excess light.
Having figured out whether a violet is a light-loving plant or not, it is worth understanding that African Violet Light Requirements and lighting for violets is a determining condition for development and flowering, thanks to which your home will turn into a real flower garden.