Green care, autumn-winter maintenance
In autumn and in the cold months of the year the maintenance of green areas still holds, as mowing lawns and cleaning the leaves are needed to protect plants from the cold, and also for transplantation and fertilization depending on the blooms that will flower in spring. The range of machines and equipment used for these functions is wide and guarantees optimal results
Green has its own charm and function throughout the year, but they must be supported by appropriate work and maintenance. In autumn plants change their appearance to face the winter season. Hardwoods wear colors that are a true spectacle in nature. In fact, in autumn, when the leaves are nearing the end of their life, the chlorophyll decreases and the colors that were hidden before by the chlorophyll green appear. Plants produce, in addition to chlorophyll, other pigments as carotene and anthocyanins which, with the reduction of chlorophyll, shine with the most different colors on the foliage. Before falling dead to the ground, leaves take on a brownish or grey color caused by the death of the chloroplasts. Even in the winter months trees, although without leaves, retain the charm of the intertwining of their branches and of their bark that changes color; unfortunately, few only perceive this beauty.
But there are evergreen trees, such as the strawberry tree (Arbutus unedo), which begins to bloom in winter to bear fruit in the following autumn. This small tree or bush, typical of the Mediterranean area, offers flowers, white bell-shaped, fruits, ripe red berries gathered in clusters, and green leaves all year round. However, the best show is offered during the winter months. It is also a symbolic plant because the Arbutus along with the bear that eats the fruit, is part of the symbol of the city of Madrid, moreover, a branch of a strawberry tree with two fruits, appears in the symbol of the province of Ancona.
Among the herbaceous plants that flower in winter as well, the pansies, which represent the undisputed protagonists of the winter garden, deserve a quotation. They are planted in small groups, in pots or directly in the ground around deciduous bushes, giving color to the garden with blooms that flower even under the snow. The Snowdrop (Galanthus nivalis), typical of the mountain areas, is a bulbous that grows under the snow and gives the first flowers of the year, small and white, as soon as the snow melts.
In autumn and winter nature, thanks to the green, maintains its charm that needs, however, to be supported by works typical of this period. In autumn the works have the function of preserving the green from the winter cold, while at the end of the cold season the works are preparatory to the spring awakening. These works can be summarized as follows: protection from the cold; lawn cutting and cleaning; fertilization; sowing, propagations and plantations; cleaning and aerating; pruning.
Protection against cold
Plants sensitive to the cold, as jasmine can be, are protected from the cold by covering them with plastic sheeting that must be transparent as plants, even in winter, need light. When plants are in pots, they must be placed in protected corners, sheltered from the cold, or, if possible, move them in cold or temperate greenhouses. When setting up these greenhouses, be careful to provide one or more windows, both to allow the exchange of air, and to avoid reaching high temperatures during sunny days. For pot plants, autumn is the best time to change containers. For this operation, it is necessary to use new containers and soil of good quality.
Lawn mowing and cleaning
Height and frequency of mowing turfs depend on the turf type (ornamental, for sports, recreational, etc.). In any case, the rule says that the last autumn cuts must leave the lawn higher than the previous ones.
In the autumn-winter period cleaning the lawn means, above all, collecting the leaves and it is linked to the type of arboreal green and scrubland. This operation is always necessary because the presence of the leaves, as well as of the “needles” of the conifers, leads to a reduction both in the usability of the carpet and in the aesthetic appearance. Leaves and “needles” can also lead to the spread of fungal diseases because of the setting of an environment favorable to their development. The equipment to be used ranges from rakes and manual metal brooms to blowers and exhaust fans driven by an endothermic or electric motor, carried by the operator. On large surfaces, trailers, equipped with containers in which the leaves are conveyed through suction nozzles are used. This cleaning operation must be repeated several times because the fall of the leaves is gradual over time and lasts until winter. The leaves collected can constitute raw material to produce compost, or mulch material to be placed at the base of trees and bushes.
Fertilization
Fertilization must be implemented according to a specific program based on: determination of the annual dose of nutrients (kg/ha) according to the species and the nature of the soil; choice of the fertilizer to be used.
The annual dose should be split over the year according to the type of fertilizer; in any case, before winter and at the end of it is good to fertilize, respectively, to protect plants from the cold and to prepare them for spring flush. To reduce interventions, slow-release fertilizers are increasingly used, especially about nitrogenous fertilizers. The distribution of granular fertilizers is carried out with trolleys towed also by the same self-propelled mowers or carried by tractors. These machines are equipped with a hopper from which the fertilizer reaches one or two rotating disks that provide for spreading.
Sowing, propagation, and plantations
Autumn is suitable for sowing grass or even, in the case of degraded meadows, to run range sowing, in order to have a quick grass cover ready when spring arrives. The essences of turf belong almost exclusively to the Gramineae family. In continental climate areas, mixtures of seeds of microterme species are used, i.e. plants for which the optimal temperatures are 15°-25° C (Lolium, Festuca, Poa, etc.). In the warmer Mediterranean areas, the species used belong to the macroterms, which optimal conditions are at temperatures of 27°-35° C (Dichondra, Zoysia, Cynodon, etc.). The soil must be well prepared, and a sowing machinery derived from agricultural ones, coupled to tractors, is used. It is also possible to use combined seed drills that in a single pass perform multiple operations: soil preparation, sowing and fertilizing. When a quality sowing is required, specific lawn mowers are used, generally self-propelled. In small areas, sowing can be manually performed. Sand and peat are added to the mixture and it is better to spread it in two orthogonal passages. Range sowing interventions are performed when the carpet is very degraded (less than 100 sprouts per m2). The most used machinery adopts a combination of soil splitting, like verticut, and sowing devices. Autumn is also the period for sowing and increasing different flowering plants. That is to say, it is possible to sow plants as Calendula, Helichrysum, Cornflower, and even to prepare flowerbeds of spring-flowering bulbs by burying the bulbs of Tulips, Narcissus, Hyacinths, Crocuses. In October, it is possible to prepare some ornamental essences cuttings to be planted in spring. This preparation may concern the cuttings of roses, using old wood but also that of Lantana, Bougainville, Ortensia and Camellia. These cuttings, after having been immersed in a solution made of the rooting hormone, are covered, for a few centimetres, in containers filled with a mixture of sand and peat, in equal parts. Other operations that are performed in autumn or late winter are tree planting and transplanting. In autumn, for deciduous trees the best period is when the leaves start to fall; for conifers, on the other hand, the best month is September, while the end of winter and spring represent the best period for cypress trees and evergreen broadleaves. It is good that the plants to be planted have the “bread of earth”. The holes in which to place the seedlings can be performed manually; for shafts of certain dimensions, the hole is made with specific machinery, or with the excavator bucket. To carry out the mechanical transplant of the trees, the equipment used are of two types: machinery to make a clod around the tree mostly used in nurseries that only operate the tree removal grubbers-transplanters that, in addition to carrying out the explant also plant the trees.
This machinery can be brought from the three-point attachment of a tractor, operating with a complete hydraulic drive, or even being self-propelled with totally hydraulic controls. After the planting of the trees, it is necessary to safeguard their rooting and growth by placing splints in order to reduce the risk of being damaged by strong winds.
Cleaning and aeration
During the year a felt layer is formed in the turf because of the accumulation of the incomplete decomposition of the leaves and the remaining stems of the grass cutting. When the layer becomes too much and solid, permeation of air and water into the soil is reduced. The cleaning, performed to restore the initial conditions, can be performed as early as the end of the month of February. In some cases, a metal broom or a rake, or even a toothed harrow may do the job. Otherwise, machinery need to be used, whose working part consists of a rotor, with a horizontal axis, on which knives or blades of various shapes are mounted. These tools, rotating during the progress of the machine, make 20-30 mm deep cuts at regular intervals and remove the felt. The aeration is carried out when the ground is excessively solid, thus creating the conditions for asphyxia of the root system and lack of water penetration. The operations consist in practicing a vertical drainage by drilling or coring up to depths of 100-150 mm and even beyond. On small surfaces it is possible to work with manual tools; otherwise, machines are used whose working part consists of cylindrical dies, made to penetrate into the ground. These machines can be full (drilling machines) or empty (coring machines) which, in addition to drilling the hole, also remove the soil. After aeration, it is necessary to distribute a thin layer of a mixture of sand and peat. The operation on small surfaces can be carried out manually with the support of a rake, or by using trailed or carried-out sanders.
Pruning
In February, if there are no strong frosts, roses, as well as some species of flowering plants, can be pruned. For plants that bloom in the middle of winter, such as Forsythia, pruning in this period should be avoided and should be postponed after flowering, as the flowers are produced on the branches of the previous year, therefore anticipating the cut before the flowering, it is likely to eliminate most of the flower buds. The flowers of plants that bloom in summer instead, come on the new branches, therefore pruning is carried out in February or March. During these months, also pruning on hedges and ornamental trees are carried out. For pruning evergreen hedges, scissors, shears and hedge trimmers are used. Pruning shears allow cuts of branches with a diameter not exceeding 10-15 mm; for larger diameter branches, pneumatic shears are used to reduce fatigue in all conditions. Shears can have a normal handle or a handle with long levers that allows to exert a greater cutting force. An endothermic or electric motor can drive hedge trimmer machines. The secluded cutter can be tilted from 0° to 90°, in order to allow cuts with different inclination. They can be equipped also with a handle with telescopic extension, which allows cuts to be made even at high altitudes. The pruning of trees instead is related to their size and development and may require the use of chainsaws as well as of lifting platforms. The branches deriving from pruning can be treated by chipping machines, that can be found in the market with models suitable for all working conditions.
