Characteristics of the plant, agricultural technology in the cultivation of grevillea, flower reproduction, the fight against diseases and pests, interesting facts, types. Grevillea belongs to the genus of representatives of the flora attributed to the Proteaceae family, which includes dicotyledonous plants with two oppositely growing cotyledons in the embryo. Most of all, the area of distribution of Grevillea falls on the lands of the Australian continent, the islands of New Guinea, New Caledonia and also the territory of the Indonesian island of Sulawesi. This genus includes up to two hundred varieties.
The plant was first described at the beginning of the 19th century (in 1809) and the term "Grevillia" was chosen to define it. The flower owes this name to the Honorable Sir Charles Francis Greville (1749-1809), who was a renowned British antiquarian, botanist, collector and politician. Also, this prominent figure was a member of the Royal Society and the Linnaean Society of London, engaged in research in the classification of representatives of the flora of the planet.
This exotic inhabitant of the subtropical regions of the planet is an evergreen flowering plant that can also take both shrub and tree-like forms. Their height can vary from half a meter of shrub shoots, inclining to the soil surface, to thirty five meter giant trees in its homeland. However, in indoor conditions, the branches can reach only 2 meters in height, especially if the plant is kept cool and with sufficient illumination.
Grevillea leaf plates can grow both attached to the petioles and completely sessile. The outlines of the foliage are also quite diverse: it can be a simple leaf or deeply double pinnately dissected. The leaf edge is either smooth or curved, resembling large teeth. There is also venation along the surface, which varies from reticular to parallel arrangement. The color also varies greatly for each variety: it can be forest greenish, changing to greenish-bronze or even silver. Moreover, the shade of the foliage directly depends on the lighting conditions when growing grevillea. Due to the glossy surface on the leaf plates, the beauty of the plant is enhanced as they look radiant and very fresh. Some people compare the luxurious foliage of this specimen of flora to the fern frond (pinnately dissected leaves).
If the plant is grown in rooms, then flowering is observed quite rarely. Usually the flower is bisexual, with tubular outlines, in which the lobes of the perianth and the long column are twisted. The color of the petals of the buds can take on red, pinkish or yellow and orange-red hues. Inflorescences have racemose or bundle-like outlines, the number of flowers from which they are composed is also varied.
Because of its effective appearance, Grevillea is best grown as a tapeworm crop for large halls, lobbies, and the like. The most favorite variety among flower growers is the powerful Grevillea variety, which in its native Australian continent is called "silky oak", since the leaf lobes have a delicate pubescence. The growth rate of this "pinnate" beauty is very high, therefore, it is required to carry out a thorough pruning of the crown. In terms of the degree of complexity of care, the plant is medium-difficult, since during cultivation it will be necessary to provide special conditions for keeping during the dormant period and few growers will be able to maintain them.
Tips for growing grevillea from seeds, care
- Lighting. This green beauty loves to “bask” in bright, but diffused lighting. However, in the summer, when the plant is on the sill of a window with a southern location, it will be necessary to shade from direct sunlight. Western window sills are best suited for growing.
- Air temperature. Grevillea should always be placed next to the window, and it is desirable that the temperature readings fluctuate between 15-18 degrees, and with the arrival of the winter period, you will have to move the pot with the plant to a cool room where the temperature will be maintained at 8-10 degrees.
- Watering for grevillea, it must be done very carefully. If you allow at least once that the soil in the flowerpot is flooded or too dry, then irreparable harm will be inflicted on the plant. Therefore, from spring to summer, the soil should always be slightly moistened and watering is moderate, however, the frequency of moistening is adjusted based on heat indicators. In winter, watering is significantly reduced.
- Air humidity when growing a pinnately dissected plant, it must be high, otherwise the tips of the leaf lobes will dry out and spider mite damage may occur. However, since the leaves of some varieties have pubescence, spraying is not the best way to reduce dryness in a room, but if there is no choice, then it is used. Only soft water is taken for spraying, otherwise whitish stains will appear on the leaves. You can also place vessels with water and mechanical air humidifiers next to the Grevillea. It is recommended to install the pot with the plant in deep and wide containers, at the bottom of which chopped sphagnum moss, expanded clay or pebbles are laid. A small amount of water is poured there, which, evaporating, will raise the humidity indicators. The main thing is that the bottom of the flowerpot does not touch the edge of the liquid, in order to avoid rotting of the root system.
- Fertilizers. As soon as the Grevillea leaves the winter rest regime, and signs of increased growth appear, it is necessary to begin to feed the plant. This time stretches over the spring and summer months. The frequency of top dressing is once every 7-14 days. In this case, liquid preparations for indoor plants are used, which are a complete mineral complex. It is recommended to follow the instructions for diluting the fertilizer.
- Transfer and selection of soil. When the bush is still young, then changing the pot and the soil in it is required annually in the spring. The capacity is taken twice as large in size from the previous one, but not deep. It is important that a layer of drainage material is laid on the bottom (about 2-3 cm of medium-sized expanded clay or pebbles). When the Grevillea is already large and heavy, then they are limited only to changing the top layer of the soil, adding a substrate with top dressing already introduced into it. There is evidence that the plant can be grown on hydroponic material. The substrate for transplanting is selected slightly acidic, it can be mixed independently from leafy soil, coniferous soil, peat soil, river sand with the addition of sifted brick chips (in a ratio of 1: 2: 1: 1/2).
- Pruning Grevillea is carried out regularly to restrain growth and compact the shrub. Pruning is well tolerated by this green beauty. This operation must be performed before the start of the activation of vegetative growth. If you do not pinch the shoots, cut the branches, then they are ugly stretched, and for decorativeness it is important that the gaps between the leaves are small.
Recommendations for breeding grevillea at home
It is customary to propagate this plant using cuttings and sowing seed material.
For seed propagation, only fresh samples should be taken, as their germination is very short-lived. The sowing operation is carried out from January to March. A wide container is taken and filled with a mixture of peat soil and coniferous soil (equal parts). Seeds are laid evenly on the surface of the substrate and powdered with a layer of soil. Then the container is covered with glass or a plastic bag - this will create the conditions for a mini-greenhouse, with increased humidity. It is necessary not to forget to regularly ventilate the seedlings (so that the crops do not rot) and, if necessary, spray the soil from a spray bottle. As soon as the sprouts hatch, it is recommended to remove the shelter. When a pair of true leaf blades appears in the sprouts, transplantation is carried out in separate pots with selected soil for growing Grevilleas. Vases are placed in a warm place with good, but diffused lighting.
For vegetative propagation using cuttings, the material is cut at the end of the summer season. The branch should be semi-lignified and with a heel. The cut of the cutting is treated with a root formation stimulator and planted in a moistened peat-sandy substrate or plain sand. Seedlings must be wrapped in a plastic bag or placed under a glass vessel. For better rooting, it is recommended to maintain heat indicators in the region of 18-20 degrees. You also need to remember to air the seedlings. When the cuttings take root, they will have to be transplanted into separate, shallow containers with drainage at the bottom and a suitable substrate.
Diseases and pests of grevillea
The following troubles can be distinguished when cultivating Grevillea in indoor conditions:
- if in the winter the plant was not kept in cool conditions, then the leaf plates acquire a yellow tint;
- growing in strong shade or high temperatures (especially during dormant periods) will lead to leaf shedding;
- in case of insufficient illumination, poor feeding or in the absence of crown molding, the shoots are pulled and the leaf plates are shredded.
If the humidity in the room where the pot with the plant is kept decreases, then there is a likelihood of being hit by a spider mite. This pest is manifested by yellowing of leaf plates, their deformation, discharge and covering of leaves and branches with a thin cobweb. To fight, it is necessary to regularly (once a week) inspect the leaves, increase the humidity in the room in any way and treat the bush with an insecticide.
Interesting facts about grevillea
The flowers of some varieties of Grevillea have not only a fragrant pleasant aroma, but they contain a very sweet nectar, which is why it is customary for aboriginal peoples living in the native territories of the flower to eat the buds.
Grevillea species
- Alpine Grevillea (Grevillea alpina) is a shrub with low height and strong branching. Its dimensions rarely exceed 1 meter. On the shoots, leaf plates grow very densely, and there is pubescence in the form of a delicate whitish felt. The leaves take outlines from narrow-lanceolate to narrow-elliptical, about 2.5 cm long, dullness occurs at the apex, the edges of the plate are slightly curled. On the underside of the leaf there is a silky pubescence, and the top is painted in a dark emerald color. The flowers are located at the tops of the shoots and are small in size, from which small bundle-shaped inflorescences are collected, in which there are only a few buds. Petals in flowers at the base are colored red, at their tops are yellow.
- Grevillea banksii can have both a shrubby form of growth and grow in the form of small trees. Their dimensions rarely exceed two meters. When the shoots are still young, they are covered with dense pubescence. The leaf plates have double pinnately dissected contours, the number of segments varies from 4 to 11 units. Each such leaf lobe is distinguished by a narrow-lanceolate shape, its color is green on top, and the reverse side, pubescent with small reddish hairs. The length of the entire leaf ranges from 10–20 cm. The pedicels and perianths also have pubescence, which is provided by small, dense and very fluffy hairs. Pedicels and perianths begin their growth from the axils of the leaf plates growing at the tops of the branches. The petals of flowers are painted in bright red or deep pink color. From 2-3 pieces of buds, racemose inflorescences are collected.
- Grevillea robusta can be found under the name "Silk Oak". This tree-like representative of the flora can reach up to 3.5 meters in height. The branches usually grow bare, with a gray color of the bark, and the shoots have short pubescence. Large leaf plates, reaching 15–20 cm in length. Their surface has a double-pinnate dissection, in which 25–35 lanceolate leaf lobes are formed. The edges of the leaves are folded or coarsely toothed, the upper surface of the leaf is bare, and the reverse side with pubescence is yellow. The flowers are up to 12 cm long and have a fragrant aroma. One-sided lateral racemose inflorescences with orange-colored flowers are collected from the buds. The native territories of this species are considered to be the lands of New South Wales, Victoria (on the Australian continent), where the plant likes to settle in humid forests with a subtropical climate. The plant is usually grown in cool rooms, flowering is rare.
- Grevillea rosemary (Grevillea rosmarinifolia) has a bushy form of growth, the height of the shoots rarely exceeds the indicators of 1, 8 m. They have dense pubescence. The leaf plates are whole-edged with narrow-lanceolate outlines, up to 10 cm in length. At both ends, the leaf has a narrowing and sharpness. Above, the surface is bare, and the underside of the leaf is covered with silky hairs. Flowers appear devoid of pedicels (sessile). From them, multi-flowered inflorescences of racemose outlines are collected. Their location is finite, the length is short. The petals of the buds that make up the inflorescence are distinguished by a blood-red color, their tube is curved, its length reaches 1 cm.
- Grevillea johnsonii is a rounded shrub. Leaf plates with a glossy surface, their contours are pinnate. The foliage is painted in a dark green color scheme. The size of the plate varies between 12-25 cm. The flowers appear with pink-cream, as if poured from wax petals. A high-lying inflorescence is collected from them.
- Grevillea thelemannina differs in a variety of varieties: it can be both creepers and plants with a shrub form of growth. The leaves are feathery with a color ranging from grayish green to pure green. The flowers are collected in bunch-shaped inflorescences. The petals of the buds are pink with green specks.
- Grevillea juniperina has the shape of a shrub with a rounded crown. The leaves are thin in outline, their shape can vary from spear to simple. The flowers form inflorescences with slightly hanging contours. The color of the petals of the buds is very diverse.
- Grevillea beadleana has a shrub growth and small size. The flowers are painted in a dark red tone.
- Grevillea thyrsoides. In this plant, leaf plates are pinnate, with a deep dissection into segments-lobes. The color of the petals in the flowers is pinkish. There are varieties with pure red buds "Cunberra" and the species "Constance", the flower petals of which are shaded with orange-red color.
What a grevillea looks like, see this video:
