This article throws light upon the nine main steps for growing of shrubs. The steps are: 1. Soil 2. Preparation of the Ground 3. Propagation of Shrubs 4. Planting of Shrubs 5. Watering 6. Filling of Gaps 7. Irrigation 8. Weeding 9. Pruning of Established Shrubs.
Step # 1. Soil:
Any garden soil is suitable for growing shrubs. Height and rate of growth depend upon to some extent on type of soils. If soil is bad, their top layer up to 45 cm should be removed and refilled with good fertile and well-drained soil. The shrubs can be grown in varied pH of soil. If the soil is highly alkaline or acidic in nature, it should reclaimed by using soil amendments.
Following is the list of shrubs which can tolerate high pH of the soil. Salt tolerant shrubs are: Bougainuillea sp., Russelia equistifolia, Theuetia peruviana, Nerium indicum and Caesalpinia pulcherrima. Salt sensitive shrubs are: Buddleia asiatica, Lagerstroemia indica, Barleria cristata, and Hamelia patens.
Step # 2. Preparation of the Ground:
After the alignment has been done for the planting of shrubs, soil should be prepared thoroughly al-least 15 days prior to planting. Prepare the pits of 60 cm deep and expose the soil to the sun for at-least 2 weeks. Refill the pits with the mixture of soil and farmyard manure (2-4 baskets/pit).
Fill the pits 10-15 cm higher than the general level of the field to avoid the formation of a depression after the first irrigation. Prepare the rest of the ground by digging it about 30 cm deep and removing all the weeds. Chlorphyrphos @ 5 ml/1 of water should also be mixed with the soil to prevent the damage by termites.
Step # 3. Propagation of Shrubs:
The shrubs are propagated by seeds, cuttings and layering.
By seeds:
Seeds are collected when they are fully ripe. They are dried in the shade and stored in airtight bottles in dry places. In rainy season, nursery is prepared and seeds are sown. Seedlings are transplanted in prepared ground. The shrubs which are mainly propagated by seeds are: Stenolobium stans, Theuetia peruviana, Caesalpinia pulcherrima, Calliandra sp. etc.
By cuttings:
Majority of the shrubs are propagated by cuttings. The best season for propagation by cuttings is rainy season, although cuttings can be made in February-March if water supply is not limited. The cuttings are made 15-20 cm long and planted in pots or beds containing ample of sand.
The plants raised from cuttings are planted in the next planting season. The shrubs propagated by cuttings are; Hibiscus rosa-sinensis, Achania malvaviscus, Jasminum sambac, Hamelia patens, Bougainvillea, Cestrum diurnum, Cestrum nocturnum, etc.
By layering:
The shrubs which are not easily propagated by seeds or cuttings are propagated by this method. In rainy season, layering is done by removing the bark of 2.5-3.0 cm long and wrapping by garden soil and sand mixture or sphagnum moss. The shrubs like Bougainvillea, Ixora sp., Jasminum sambac and Jasminum multiflorum (ground layering) etc. are propagated by layering.
Step # 4. Planting of Shrubs:
The best planting season of shrubs is rainy season. After the onset of monsoon, planting can be done. Planting can also be done successfully in the month of February-March depending upon the water facilities during summer months.
The planting distance of different shrubs is variable according to their height and spread. The tall shrubs may be planted at the distance of 150-180 cm. In very large shrubbery two or more shrubs may be planted in groups for better results.
The medium shrubs should be planted in one or more lines between tall and dwarf shrubs. They are planted at a distance of 90-120 cm. The dwarf shrubs in front line should be planted at-least 30 cm away from the inner edge. The distance of planting is 45-90 cm depending upon the shrub. For the best effect they should be planted in a group of 4-6 plants in the length of 3.0-4.5 m.
Step # 5. Watering:
Immediately after planting, watering should be done frequently till they are established.
Step # 6. Filling of Gaps:
Newly planted shrubberies need attention in the beginning specially for filling the gaps. As soon as mortality occurs, new plants should be planted.
Step # 7. Irrigation:
The shrubbery should be irrigated at regular intervals. Frequency of irrigation depends upon soil texture, season etc. Under Punjab conditions, during rainy season no irrigation is required. From September onwards, irrigation should be done at monthly intervals up to March. After that irrigation should be done at fortnightly intervals. In sandy soils, more frequent irrigation may be required.
Step # 8. Weeding:
Weeds should be removing regularly otherwise they compete with main plants for nutrients and moisture etc. During rainy season, one or two weeding’s are necessary and after that occasional weeding will serve the purpose.
Step # 9. Pruning of Established Shrubs:
Shrubs need careful pruning. Winter flowering shrubs e.g., Poinsettia pulcherrima, Holmskioldia sp., and Doembeya sp. are pruned at the end of summer season whereas others are pruned at the close of winter season.
Cutting back the growth of the shrubs is very important and the performance of the plants is improved. Trimming and method of their pruning depend upon the form and age. All the superfluous growth, old or weak branches are best cut at ground level or as low as possible without leaving the stub.