Apartment plants

Gardenia - Gardenia jasminoides


La Gardenia


Gardenias are medium-sized evergreen shrubs, belonging to the same family of coffee, the Rubiacee; they are plants originating from the Australian continent, from Asia and southern Africa, and there are about two hundred species of gardenia. In Italy the most cultivated species is the gardenia jasminoides, native to China, in the nurseries are also widespread hybrids of this shrub, particularly suitable for cultivation in apartments or vice versa in the garden. In nature these plants grow in wet areas, with fairly mild climates, so they are commonly grown as houseplants. If cultivated in pots they develop small roundish shrubs, no higher than 50-60 cm, with a beautiful glossy and leathery foliage, of dark green color; in spring, continuing until late summer, they produce innumerable large fleshy buds, from which bloom large white or cream flowers, intensely scented.
The gardenia is grown with great satisfaction in interiors, but in our country, especially in the Center-South and along the coasts, it finds climates and locations also suitable for its growth outdoors, in the open ground. It thus becomes ideal to create magnificent evergreen hedges, also endowed with a splendid and fragrant flowering.
This essence undoubtedly requires experience and suitable land, but it is able to give great satisfaction to those who decide to devote themselves to its cultivation.

Grow gardenias in the apartment



These beautiful flowers are sold in flower practically all year long; in nature, however, gardenias only bloom during the warm season, with a warm climate. Plants purchased in flower nurseries, also for example during the month of February-March, are generally forced to bloom, ie they are kept in greenhouses with daytime temperature and lighting similar to those of a beautiful June day. For this reason it often happens that our gardenia jasminoides, in the space of a few weeks, loses flowers and buds, tends to ruin itself and seems to stop its development completely.
When we buy a gardenia we try to remember that we will almost certainly make it suffer a strong change, from the warm, bright and humid nursery to the apartment: warm, dry and quite dark. For this reason, don't worry if some flowers or buds fall, it is more important to try to adapt the plant to the house; within a few weeks it will resume flowering without problems.
So as soon as we bring our own home gardenia jasminoides let's place it in a fairly bright place, not directly exposed to sunlight, but not too far from a well-lit window. In addition to the light, the element that most differentiates a home from a nursery or garden is certainly the environmental humidity, or at least, it is the characteristic that most influences the development of our plants.
Gardenias love climates that are not too hot and humid, and good air exchange. We remember therefore to place the plant where it has a good air exchange, possibly in a room that we ventilate daily; furthermore we avoid placing it near direct heat sources and every day we vaporize the leaves with demineralized water, to increase the environmental humidity. During vaporisations we avoid wetting flowers, which would otherwise quickly turn brown and wither.

































































GARDENIA IN BRIEF

Family, genus, species

Rubiaceae, Gardenia, about 60 species
Type of plant Shrub or small tree
Foliage persistent
Height 1 meter in pot; 2-3 meters in the open ground
Growth slow
Maintenance Quite challenging
Rusticitа From fragile to medium rustic (some withstand -12 ° C, others do not tolerate frost)
Exposure Half shade, bright shadow; very bright in the apartment
Ground Woodland + sand + little field soil, well drained
pH From neutral to acid
Irrigation Frequent, without stagnation; demineralized or rainwater
Environmental humidity high
Ideal temperature for flowering 18 ° C
Avversitа Aphids, cochineals, root rot, gray mold
Propagation Cutting, sowing

Grow a gardenia in the garden



Some species and varieties of gardenia can easily withstand frost, especially those of Asian origin. We can therefore decide to put our gardenia in the garden, in a partially shaded place, and protected from too intense frost and the winter wind. Also in this case we try to get a gardenia that has been cultivated specifically for the garden, especially if we don't buy it during a hot period of the year; in fact a gardenia in bloom in February has certainly been cultivated in the heat, and it is unlikely that it can be placed outdoors immediately, with a harsh climate. So if we want to plant our gardenia in the garden, let's do it preferably in a time of year with a mild climate, or gradually adapt it to outdoor life, to put it permanently home only when every danger of frost has passed. Once planted and rooted the plant can withstand up to -7 / -8 ° C, in any case we provide to cover it during the winter if the temperatures are very low.

Origins and characteristics of the Gardenia


The genus Gardenia takes its name from a Scottish naturalist, Alexander Garden, to whom it was dedicated. It belongs to the Rubiaceae family and includes about 60 widespread species, in the spontaneous state, in the tropical and equatorial areas of the planet. The most widespread in our continent, the Gardenia Jasminoides, is native to China, Japan and Oceania and was introduced by us in the mid-1700s. In Italy, however, the grandiflora and the Fortuniana are also widespread (the latter being more suitable to outdoor cultivation).
They are generally slow growing shrubs, from 1.5 m up to more than 3. The evergreen leaves are lanceolate-elliptic, thinned at the apex and at the base, of a beautiful glossy dark green, quite consistent. The flowers are mostly solitary, simple or double, white or pink, with a very intense aroma. Their production is in almost the right conditions, but much depends on the species. On the market you can find specimens in bloom even in winter, as it tolerates forcing well.

Soil and watering



Gardenias develop a root system that is not too wide, which generally tends not to sink too much into the ground, but rather widens near the surface; for this reason the roots of gardenias suffer very much from humidity. To have a shrub that is always healthy and lush, it is advisable to keep the soil moist for most of the year, from March to October; avoiding excessively soaking the substrate.
We use good soil for acidophilic plants, mixed with a small amount of sand or pumice stone, to better aerate the substrate and increase its drainage.
Watering is practiced every time the earth appears dry; in the garden, gardenias are generally watered every 3-4 days, but only during the summer and far from periods of rain; avoiding winter watering. To prevent the soil from drying excessively, remember to practice good mulching at the foot of the shrub, using bark or lapillus, so as to keep the surface layer of the soil always fresh and moist, and also avoiding the development of weeds.
During the cold months the watering in the apartment will be only sporadic.
From April to September we mix a good fertilizer for flowering plants with the water, and periodically perform a soothing treatment, especially if the foliage tends to turn yellow.




























Exhibition for the Gardenia


Gardenias grow best in a half-shade or bright shadow location. If they are to receive a few hours of direct light, it is preferable to have them in the morning: too hot a sun could cause dehydration and leaf burns as well as dry the soil quickly.
If we cultivate gardenias as houseplants, we will instead have to place them in an extremely luminous position, avoiding however that the sun's rays reach it directly: in particular in summer it will be good to screen the windows with thin light-colored curtains. We can also move our vase outside. Ideal then is to shade it slightly, place it under a pergola or a deciduous tree.

Ground



From this point of view, gardenias are rather demanding. They want a soil that is neutral to subacid, but rich in organic substance and able to always remain slightly cool; in any case, even slightly minimally calcareous soils should be avoided: they could cause the onset of leaf chlorosis, scarce growth and flowering and finally deterioration.
In general it is advisable to cultivate them only where the soil is already suitable in itself; alternatively, if ours were clayey, asphyxiated and rich in calcium, we can work digging and changing it in depth.
An excellent expedient is to interrupt large concrete basins (such as those used in construction) or private vessels of the bottom: in this way we will be able to isolate the area from the surrounding environment.
The ideal compound, both for the outside and for growing in pots, is composed of peat, ground of leaves and a bit of sand, added with a bit of manure or field soil.

Planting in the ground



We operate around March-April: we dig a deep and wide hole at least three times the ground bread of our plant.
In addition to the possible substitution of the substrate it is extremely important to create a thick draining layer based on expanded clay, pumice or pozzolana on the bottom. We insert the plant and the soil, compact and irrigate abundantly.

Potted plant



If possible, we use larger or deeper vessels (bowls are ideal). On the bottom we lay a draining layer at least 3 cm thick. Insert the plant and fill it with the soil. We can use a mixture for acidophilic, but we will get better results by adding some perlite and manure. Even a small part of garden soil can be useful to keep the roots fresh for longer.
Repotting should be done at the end of winter and, usually, it is sufficient to work in alternate years.

Rusticitа


There are more or less rustic gardenias. The Jasminoides species is generally the most tolerant of cold, succeeding, in the right soil conditions, to resist even at -5 / -10 ° C: so let's choose it if we live in the Center-North. Let's place it where it receives light during the first hours of the day, we prepare a thick mulch and cover the foliage with suitable fabric.
More delicate are instead the Grandiflora, the Thunbergia and the Lucida: they do not bear frost and must therefore be grown outdoors only in the extreme South. Elsewhere they are indoor plants or temperate greenhouses or in any case to be withdrawn at the end of summer.

Irrigation and environmental humidity



The right degree of hydration is really what can turn a stunted gardenia into a splendid specimen in any season.
These shrubs always love a slightly cool soil but, on the other hand, they particularly fear water stagnation. The irrigations must therefore be frequent, intervening whenever the surface is completely dry. However, the use of saucers should be absolutely avoided and excess water should flow away easily.
We can proceed from the top but, for the potted specimens, it can also be a good choice the irrigation by immersion, inserting it in a full basin of water. After about 15 minutes we will extract it and leave it to drain very well.
In any case, in addition to the fresh substrate, it is absolutely essential to always keep the environmental humidity high.
In the garden, especially in summer, it is very useful to vaporize the leaves often in the hottest hours: but avoid, if possible, to wet the flowers because they crease easily. It is also very useful to prepare a mulching layer based on leaves, straw or cut grass: it will help us to keep the roots fresh without having to constantly use the watering can.
At home, in addition to frequent sprays, we can use electric humidifiers or ceramic humidifiers to be applied, in winter, to radiators. Useful is to prepare tubs full of water and expanded clay near the gardenia.
Let us remember that it escapes limestone: as far as possible for all purposes we use rainwater or demineralised water.

Fertilization of the Gardenia


In pot the gardenias in pots, especially during the vegetative period, benefit from the support of a fertilizer for acidophilic plants: we choose a liquid formulation and mix it with the irrigation water, every two weeks.
In the garden we choose a slow release product specific for this type of shrubbery, with a low content of calcium and chlorine. Generally they are administered after three months, starting in March and suspending the arrival of the bad season.

Pruning of the Gardenia


Pruning is not strictly necessary: ​​the gardenia has in fact a very slow growth. It may be necessary to intervene only on badly set, old or damaged specimens.
It operates immediately after flowering by shortening the branches to a maximum of 1/3 of their total length. We totally eliminate those seriously compromised.
We avoid cutting at the end of winter: we would compromise the vintage flowering.
On the contrary, withered corollas are eliminated as soon as possible: we will stimulate new growth and possibly the production of other buds.

Pests and diseases


The insects that most frequently attack the gardenia are aphids and scale insects. We use specific insecticides, but only if their number is consistent and compromises the beauty of the leaves with the production of honeydew.
Radical rots should be prevented as much as possible: if they occur anyway we try to change the substrate as much as possible and administer propamocarb or foseti-aluminum one or more times.

Gardenia - Gardenia jasminoides: Variety of gardenia



Gardenia jasminoides
It is the most cultivated and widespread species: it grows up to 2 meters. The flowering is scalar and extends from May to September. Rustic enough: it can withstand even -7 ° C, but for short periods, especially in well-drained soil. The 'Kleim's Hardy' cultivar is even more resistant (up to -12 ° C). The "Veitchiana" is distinguished instead by the beauty of the foliage, variegated with white, but is however very delicate.
Gardenia grandiflora
In a suitable climate it also grows up to 3 meters and is suitable as an isolated specimen but also for the creation of beautiful hedges. You should never go below 10 ° C to see it bloom well the following year.
Gardenia thunbergia
Shrub or small tree up to 5 meters high that bears fragrant flowers. Suitable for growing where it never drops below freezing level.
Gardenia amoena up to 150 cm high, native to India, it is endowed with numerous thorns. The flowers are white, but the edge of the petal is pink. Suitable for hot climates, where you never freeze.
  • Gardenia flower



    The Gardenia plant is native to China, it is highly esteemed by growers, and for this reason it turns out to be

    visit: gardenia flower
  • Gardenia gardening



    The gardenia includes many species of which the most widespread is the Gardenia jasminoides. The family he belongs to

    visit: gardenia gardening



THE CALENDAR OF THE GARDENIA

Flowering

From May to October
Planting-repotting March April
Composting April-October
Pruning October
Talea Spring (with temperatures from 18 to 20 ° C)
Sowing Spring-summer (with temperatures from 19 to 24 ° C)