There are more or less rustic. The former can be grown almost anywhere in our country. The others, on the other hand, must be kept in pots or are reserved for the southern regions and coastal areas.
Genus of about 40 species of evergreen trees and shrubs, originating in the southern United States, Mexico and South America; some are without stems, others have erect stems, vigorous, sometimes with some branching, which develop with age. The species cultivated in apartments have woody stems, erect, poorly branched, with smooth bark; at the apex of the stems is produced a thick head of long fleshy leaves, rigid, pointed, green; there are varieties with variegated foliage.
In summer, occasionally, the adult painte produce tall panicles, which carry numerous bell-shaped flowers, of white or cream colour.
In its spontaneous state, the yucca is pollinated by the small moth Pronuba, which lays its eggs in the ovary of the flower, pollinating it. Although the larvae feed on the seeds that germinate, they remain in sufficient numbers for reproduction.
Varieties cultivated: Yucca aloifolia, Y.a. draconis, Y. brevifolia, Y.b. brevifolia, Y.b. herbertii, Y.
elata, Y. elephantipes (Y. gigantea, Y. Guatemalensis), Y.e. variegata, Y.Cespitosa, Y.f. variegata, Y. flaccida, Y. filamentosa, Y. glauca, Y. goriosa , Y. recurvifolia, Y. whipplei (Hesperoyucca whipplei), Y.w. caespitosa, Y.w. intermedia.
Characteristics of the yucca
The various species can have very different bearing and shape from each other: we go from small shrubs to medium-sized trees. In general, however, we can say that they are characterized by persistent and rigid foliage, with a smooth edge, almost always bearing a thorn on the tip.
The height when ripe can range from about 60 cm to more than 10 metres, without counting the floral scape, which often exceeds the height of the leaves by many metres: it emerges from the centre of the rosette and has on the top a large number of bell-shaped flowers, white, cream or, more rarely, purple.
It is very suitable for use as an isolated specimen, but it is also suitable for the formation of hedges or as a specimen for apartment or terrace, if inserted in large pots.
In the countries of origin it is also used for many practical purposes. From the leaves and roots it can get a good taste of natural origin. The leaves and trunks are used in the construction of houses. Let’s not forget that, in the areas where it is endemic, it produces very palatable fruits: it is very rare to see them here because the flowers need pollination by insects not present in our continent.
The only exception is represented by the Yucca aloifolia: to taste them, however, you have to wait until they are well dried on the plant. They have a very particular taste of liquorice.
LA YUCCA IN BREVE
Height/width at maturity
More than 10 m/up to 4 m
Very to very rustic
Sandy, calcareous, rocky. Well drained
- I write from Verona where I and my beautiful yucca plant live This plant has always enjoyed wonderful health, in the apartment during the winter and on the balcony in the summer, it is not a good place to stay.
- Good evening, I have given a pint of yucca, and I would like to keep it in the living room while having the underfloor heating system is possible ?…
- We have in the garden a beautiful yucca, about 1.70 cm high, which so far has enjoyed good health.
Recently, however, the stem has begun to show signs of erosion, as if it had been attacked by a man….
- Hello …. I would like to know where I got it wrong with my yucca, it is losing all the leaves and the stem and soft one I had to cut it also because the leaves fall … certainly I gave too much water to the yucca, it is losing all the leaves and the stem and …
Exposure: yuccas should be grown in a bright place, possibly far from direct heat sources and direct sunlight; they usually adapt without any problems even in unsuitable growing conditions. Although they are mainly grown in apartments, some species can easily withstand frost, so they can be grown in the garden.
They prefer fairly cool temperatures, therefore in summer it is advisable to position them in a partially shady and well aerated place; during the winter months we should remember to vaporize the foliage frequently with demineralized water.
Watering: during the vegetative season, the Yucca, from March to October, water abundantly, always waiting for the soil to dry well between one watering and the other. When temperatures fall, watering should be thinned out; in winter it should be watered sporadically. During the vegetative period, provide specific fertilizer for green plants, every 15-20 days, mixed with the water of the watering.
Soil: grow in a balanced universal soil; to improve drainage, add a good quantity of sand or lapillus to the soil. Usually these plants don’t develop a conspicuous radical apparatus, however let’s remember to repot them every 3-4 years.
Multiplication: by sowing, in February-March at a depth of 0,5 cm, in a damp and well mixed mixture, formed by 2 parts of the cultivation compound and a part of coarse sand. The plants are placed in a box to be kept in the shade at a temperature of 21°C; when the seeds are germinal, the plants are moved to a luminous position. When the plants are at 5-8 cm, they are transplanted individually.
Pests and diseases
Generally, yucca plants are very afraid of cochineal, foliar and radical, especially in conditions of low humidity. The leaf will show dark spots on the underside. The quickest remedy is to remove these spots with a cotton ball soaked in alcohol, or gently rub the leaves with a sponge to remove the parasites.
The plant may also suffer and become ill from other causes, such as poor lighting, excessive watering or the attack of fungi such as Botrytis. In this specific case, the plant can even die if not treated deeply. It is therefore a good idea to use specific fungicides and eliminate the affected parts of the yucca.
Many yuccas can be grown in pots. If we live in an area with cold climates it will be the only solution in case we want to grow specimens sensitive to low temperatures. They will only need a little more attention, but they will always give great satisfaction.
IL CALENDARIO DELLA YUCCA
From May to October
From February to April
Soil and vase composition
The same rules apply as for plants growing in the open ground. In a container, however, you have to pay even more attention to the quality of the drainage, creating a thicker layer of gravel on the bottom and adding a little more pebbles to the compost.
Almost all of them are able to withstand temperatures as high as 5 °C. Those that are withdrawn from the house should be kept between 15°C and 18°C, so neither too hot, nor too cold. The position in all seasons should always be well-lit.
Light and excessive heat can only be a problem during the summer, especially if concentrated from a window glass. In that case, it is best to move the specimen to where it is only reached by the sun in the morning or evening.
Outside, it can withstand temperatures even above 30°C.
Irrigation and fertilization
Interventions must be carried out only when it has been ascertained that the soil is completely dry even in depth. The ideal is therefore to water abundantly (until the water comes out of the drain holes) and let a long time pass before intervening again, always monitoring the situation of the substrate by inserting a finger well in depth.
From spring to autumn, every 15 days, it is useful to give a liquid fertilizer for green plants, diluted with irrigation water.
The repotting is done every four years, choosing a container slightly larger than the previous one (+2/4 cm in diameter). As the plant grows, it will become increasingly important to choose a heavy container: the greater the weight, the greater the stability of the complex.
Large yuccas may no longer be repotted: the most superficial layer of substrate is removed and replaced.
To keep the leaves free from dust (and avoid the onset of pests such as the red spider) it is good to periodically wipe a damp cloth. If our apartment (or balcony) is very dry during the hot season, it is always a good idea to use light vaporization with rain or distilled water.
The basal leaves of the yucca tend to dry out and are replaced by new ones. It is a physiological event: we have to wait for the leaf to be completely dry and then tear it off at the base with a dry blow.
Usually their structure is composed of two or three main trunks that should never be touched.
On the other hand, it is possible to intervene on the secondary ones, always leaving, however, at least three leaves on each one. The best period is always before the vegetative awakening, between February and March.
If a branch has become too large let’s cut it at the base, covering the area with a good amount of mastic.
Flower stems are eliminated when the flowers are withered.
In our continent, only agamic propagation can be carried out, as the flowers are not pollinated by insects.
It can be tried with the cutting of trunk or head: we cut with a sharp saw a portion of trunk about 30 cm long (or 15 cm from a lateral branching). Let’s dust it with a rooting product and put it in a very draining compote. The roots develop in 30-60 days and new leaves appear. At that point it can be transferred to the final compost.
The simplest method, however, is to take basal suckers. They are separated from the mother plant by means of a well-sharpened and clean knife. Ideal are those of at least 20 cm and with 4 leaves. They are then placed in 12 cm diameter pots with a mixture of peat and sand, to be left in the sun for about two months, often vaporizing.
Pests and diseases
The most frequent parasites are the cochineals, which stick to the back of the leaves for nourishing of the sap, but in apartment and in very arid areas, however, can also appear the red spider.
Rather usual, especially with poorly draining substrates and incorrect exposures, is the advent of botrytis that creeps into the plant carrying rottenness. It is very important to prevent and eventually eliminate the infected parts. Specific fungicides can be helpful.
Growing in the open ground
The genus yucca includes a large number of different species, some more sensitive to the cold, others much less. It is therefore essential, if we live in the North or in mountain areas, to inform us about the characteristics of the specimens we want to plant in the open ground.
However, there is one common characteristic: they all cannot stand the mixture of cold and humidity. The choice of exposure and the substrate are therefore very important.
To obtain a good growth and avoid the onset of rottenness you should always position the yucca in full sunshine. This is even more important for plants located in the middle of the earth in the Centre-North: the ideal location in that case will certainly be in the South or South-East, possibly near a wall where the heat can accumulate during the day to be released during the night. Early morning sunshine will help to dry up as soon as possible the moisture that accumulates on the ground.
The heat and dryness in the ground are not a problem.
To obtain a fast development and avoid the onset of radical problems it is important to insert the yucca in a very permeable and draining soil. The ideal is a compost with field earth (not too clayey), a bit of sand and a lot of gravel.
However, some varieties (such as the glorious or the elephantipes) are very tolerant and adapt to almost all substrates.
The best time to do this is in spring, so that the plant can root and free itself before the arrival of the cold season.
A good wide area should be excavated and a thick draining layer of fine gravel should be created at the bottom. Then insert the specimen and the compost, compressing well and ensuring that it is well flat. Let’s irrigate abundantly.
Yucca: Variety of yucca
Here are some of the most popular varieties in our country:
Y. brevifolia rustic up to -12°C, avoiding damp. It has branched and disordered trunks with tufts of short leaves. The spines are very sharp. It can reach 9 metres in height.
Y. Glorious very tolerant of soil and exposure and totally rustic. It can have a single or multiple trunk, dark green straight leaves ending in a thorn. The flowers are white tending to pink. It can reach 3 metres in height.
Y. desmetiana medium rustic and small (rarely more than 50 cm). However, it widens easily and has soft blue-green leaves, purple when young.
Y.elata medium rustic, suitable for arid and sandy areas. The trunk is not unique with a crown of soft leaves and surrounded by filaments. Up to 5 metres high.
Y. elephantipes very suitable for Central-Southern climates (down to -8°C), where it adapts to many different climate and soil conditions. It has lanceolate and sharp leaves and a spectacular and fragrant flowering. It can develop more trunks, up to 5 meters high.
Y. filamentous totally rustic, it can withstand humidity as well. It is often used as a soil cover and has a beautiful, cream-coloured, bell-shaped bloom. Up to 3 metres high.