THEthe black thumb does not exist. To keep a plant in good health, the magic word is to take care of it: just as you need to know the needs of a child or an animal to look after them in the best possible way, you need to read up on the chosen vegetable, know what climate and terrain it comes from, and how much sun and water it needs. And then, dedicate some time to it every day. Seeing it grow luxuriantly repays every effort. Sebastiano Guarisco, a graduate in management engineering and nurseryman in the family business Le Georgiche in the province of Brescia, grew up with plants and knows them, as he says, by osmosis. He chose to share what he learned in the field and at the Minoprio Agricultural School in Green in five minutes (Gribaudo), a very agile illustrated manual in which to find quick and easy explanations for any doubt about the world of plants. We asked him 10 elementary questions, useful for any aspiring green thumb.
Sebastiano Guarisco, nurseryman in the family business, who wrote the manual Green in five minutes (Gribaudo).
1. How do you choose the right soil?
It depends on what you want to grow. Universal soils are good for everything. In pots and planters, it is better that the soil also contains a little pumice stone and coarse material that favors drainage: stagnant water is not good for you. Then there are plants with specific needs. Camellias, hydrangeas, rhododendrons and azaleas want acidophilic soil, which contains a lot of peat. Succulents, orchids and bonsai also require special soils.
2. If I plant an acidophile like azalea in the garden how do I know if the soil is okay?
The pH of the soil must be acidic (4 to 6). Measuring it is not difficult: just get a litmus paper at the pharmacy, make a mixture with water and a handful of soil, and after letting it settle for at least 12 hours, check it by immersing the paper. To fertilize the soil in which the acidophiles are found there are special products, for example based on partially composted pine needles, which are acidifying.
Irrigate the plants as best they can
3. At what time is it best to wet the plants?
When we water, we try to avoid the thermal shock to the plants that occurs by using fresh water on a soil heated by the summer sun, in the hottest hours. Better to irrigate early in the morning or in the evening. Getting wet is important, but it must be done without overdoing it. Excess water is one of the leading causes of house plant death. The quantity depends on various factors, such as the season, the temperature, the presence of wind, exposure to the sun …
4. Which water is best to use?
The best of all is the rain one. If you can collect it, dilute it with that of the aqueduct. Limescale in tap water is never so high that it threatens plant health. Rather, the presence of chlorides and florides could cause yellowing on some indoor plants, even if it is not a frequent phenomenon.
Fighting plant diseases
5. Aphids and scale insects: how to fight them naturally?
The first rule is prevention: the plant must be kept in good health. If attacked, the insects must be removed. The mealybugs are easy to see: they are slow and can also be detached manually with a piece of paper or cotton. Linseed oil sprinkled on the infested plant suffocates the eggs and adult insects. Aphids create more important colonies. Beyond manual removal, a mixture of potassium soft soap, neem oil and nettle extract can be used. The ingredients are found in garden centers.
6. How to eradicate fungi without chemicals?
The most common is powdery mildew, or white sore, which creates a whitish patina on the upper surface of the leaf, and is rubbed off. Then there is rust, which gives dusty orange or reddish pustules on the underside of the foliar. Scab causes brown spots and yellowing. Mushrooms also have their preferences, and those who have been growing a plant for a long time know which fungi it is attacked most often by. A good remedy, also as a prevention, is the use of cupric products, which are also allowed in organic farming, such as verdigris. Or propolis, which is a natural antiseptic. As a preventive and curative treatment, there is potassium bicarbonate, to be dissolved in water and sprayed: its effect is to raise the pH of the foliar environment, making it unsuitable for fungi, which prefer an acid habitat.
Little gardeners grow up. (Getty Images)
Plants in the house
7. I have a dark area in the house: what plants can I put in it?
There are plants that withstand low irradiation better. I am Sansevieria, or mother-in-law’s tongue, which is good everywhere; the Pothos, very easy to grow; the lead plant (Aspidistra elatior); the Boston fern (Nephrolepsis exaltata), with a wilder appearance; the phalanx (Chlorophytum comosum). They are plants that naturally grow in the undergrowth, so they are used to little light.
8. Is it dangerous to keep a plant in the bedroom?
It is a false myth, linked to the fact that plants consume oxygen in the dark to burn sugars. In reality, vegetables produce on average 8-10 times the oxygen they use during the night and the consumption of sugars occurs both during the day and at night. However, the gaseous exchanges of plants are lower than those of human beings.
Duplicate the plants
9. The plant has grown, do I put it in a bigger pot?
The best time to repot is early spring. It is a good idea to switch to a size of 4-8 cm in diameter more than the initial pot. For example, from 14 cm to 18 cm, from 18 to 24 cm. The bigger the starting pot, the more you can abound with the size of the new one. If the plant is too small compared to the pot, a large part of the earth is left without root systems present and when watering an environment with stagnant humidity is generated, which favors fungi and bacteria. The plant does not die in a tight pot, it only slows down growth.
10. I have a plant that has generated daughter seedlings near the stem. How to detach them?
These formations, which are seen for example in a Pilea or a banana tree, are called suckers. The plant is flared and with a sharp and sterilized blade detaches the daughter plant with its roots from the clod, to place it in another pot. It doesn’t have to be done: in nature, in the earth, plants stay close. In a vase, if left together you get a richer effect, and when the container is too full, it switches to a larger vase.
iO Donna © REPRODUCTION RESERVED