PROPAGATION
Plants can be propagated by various means: either by sowing seeds, or through vegetative methods involving taking cuttings, budding or grafting.
Seedlings plants may differ considerably, because each seed is the product of two individual parent plants whose genetic information might be different; those plants generated by vegetative propagation appear identical to the parent plant, whose genetic information they inherit intact.
PROPAGATION BY SEED
Seed – usually hybrid annual flower and vegetable seed – can be sown it trays, and the seedlings later transplanted , or it can be sown directly in open ground, as with lawn seed and meadow mixes, when sowing seed, it is important to work with clean material and label your sowing as to variety, sowing date and even date of germination.
SOWING INTO SEED TRAYS
Sowing Mix: An important factor when sowing seeds is the growing medium, ordinary garden soil is no good as it usually harbours weeds and its drainage qualities are poor, it is best to buy pre-packed potting soil from a reputable garden centre or nursery, if you particularly want to prepare your own, the best mixture is two part coarse sand, to each 10- liter bucketful of this mix, add a tablespoon of superphosphate or bone meal, and mix well into the sowing mix.
Soil Sterilization: It is Important to sterilize the sowing mixture to prevent damping-off disease, Damping-off disease is caused by fungi that are encouraged by poor drainage and overwatering, the easiest way to sterilize the mixture is to pour boiling water over it, or to place it in a covered baking pan in the oven and bake at 80 C for 10 minutes (this will not improve the smell in the kitchen) you can also sterilize the sowing mixture by drenching it with a fungicide like Virikop or fongarid .
Sowing Seed: Seedling trays of the type bought in most garden centres are best for sowing seeds, fill the clean trays to the rim with sowing mix and level it, use a ruler to make shallow furrows in a grid pattern to the depth necessary for the seeds being used, they should not be sown deeper than two or three times their diameter, and very fine seeds need no soil covering at all, check the sowing depth on the seed packet, the distance between the furrows, known as ‘drills’, should be about 50 mm for small seeds and 75 mm for larger ones, the drills are lightly covered once the seeds have been placed in them.
Spread the seed as evenly as possible with a vibrating wrist action, then cover with a thin layer of sieved river sand, never thicker than the diameter of the seed itself, very fine seeds need no soil covering at all.
Water the sowing mix with the planted seed with fungicide like Virikop or fongarid to prevent damping-off disease, which causes seedlings to wilt and die, Label the tray with the name of the variety and the date, Most seeds germinate in two to four weeks, it is important not to overwater and to keep them in a light (but not direct sunlight) warm position, water seed trays by placing them in a shallow pan of water, fine seeds that have not been covered with soil need high humidity to germinate, this is easily provided by sliding a pane of clear glass over the tray or by covering the tray with clear plastic, remove it as soon as germination commences to prevent fungal diseases from attacking the seedlings, if you cover the tray, it is likely that you will not need to water again until the seeds actually germinate.
Pricking Out: If the seedlings are too densely packed together, thin them out to allow the remaining plants enough space to develop before they are planted out in the garden, plants are ready for transplanting when they show their first true leaves, small plants withstand transplanting better than larger ones, the shock being far less at the earlier stage, once the seedlings are large enough to handle, prick out and transplant, do this by gently pricing out a few seedlings with a pointed knife, to transplant, take each seedling between thumb and forefinger, and plant into holes made with a pencil in damp growing mix, lower the roots into the hole and firm the growing mix gently around the seedling to fill the space around the roots.
Pinching Out: Once they are settled in their new home, it is time to nip plants in the bud, as the saying goes, this means pinching out the growing tip to force the plant to branch instead of allowing it to become tall and spindly, it can easily be done with thumb and forefinger when the plants are young; but if they are allowed to become sturdy it may be necessary to use secateurs.
Damping Off: Overwatering and poor drainage are the main causes of damping-off disease which is caused by fungi, it may occur before the plant has even emerged from the soil, or can manifest as stem rot in a growing medium and causing the plant to fall over, the problem can be averted by improving drainage, correcting watering patterns, and sterilizing the soil as mentioned before.
VEGETATIVE PROPAGATION
Vegetative propagation is carried out using cuttings, division, layering, budding and grafting.
Cuttings
Slips, as cuttings are commonly named, are usually shoots or parts of shoots with buds and often with leaves as well, in some instances they may be portions of roots, leaves or merely buds, cuttings should be taken only from healthy plants, and should be of average strength – neither weak, nor excessively vigorous, as these will suffer if suddenly cut off from an abundant suddenly cut off from an abundant supply of nourishment, the size of the cutting varies: it is made immediately above a node at the top, and below one at the bottom, it may consist of only two nodes but it is preferable to have more, stem cuttings, semi-hardwood cuttings and hardwood cuttings.
Softwood Cuttings Can be made from springs to late summer during the active growing season, with softwood cuttings, lengths of 50 to 100 mm are taken from young, half-ripened growing tips of shrubs and trees, plants that can be propagated by this method are, for example, impatiens and fuchsias.
Semi-hardwood Cuttings and herbaceous cuttings are taken after the active growing season or after a growth flush, usually during the summer or in autumn, these cutting consist of a short piece of stem about 80 mm long, with at least one joint (node) having a bud that is capable of producing a new shoot, Amongst the many deciduous and evergreen shrubs and perennials that can be successfully propagated from semi-hardwood Cuttings or herbaceous cuttings are the popular pentas, penstemons and geraniums.
Hardwood Cuttings are made during autumn and early winter, in the dormant season, using wood from the previous season’s growth, the best cuttings are taken from pencil-thick wood, about 150 to 200 mm long, and with at least three leaf buds or nodes, these cuttings may take longer to root than softwood and semi-hardwood cuttings.
Root Cuttings Can be taken from any plant that will sprout from any plant that will sprout from the roots, for example, the Japanese anemone and Acanthus mollis (Wild rhubarb) Select vigorous roots and make 70-mm-long cuttings.
Leaf Cuttings can be made by using either the entire leaf or a portion of the leaf, from plants such as African violets, gloxsinias, begonias and a variety of succulents.
Rooting Mediums
The most Commonly-used rooting medium is clean-washed river sand, it is important for the sand to be kept moist river sand to be liable to dry out quickly, A half-and-half mixture of clean-washed river sand and peat moss, which retains moisture, is a good choice, the simplest of all rooting mediums is probably water, Many plants such as coleus and impatiens root very successfully in this medium , before attempting to root cutting, dip the end in a hormone powder (such as seradix) or liquid rooting solution (Dip ‘n Grow, for example) for better results, Several brands are available.
Other Methods
Gardeners interested in other means of propagation, such as layering, division, grafting and budding, should consult one of the many good books available on the subject.
PLANTING
There is more to planting trees and shrubs than merely digging holes and placing plants in them, It is important to choose carefully the right plant for the right position, taking into consideration the size of the garden, the anticipated size of the plant, the purpose of the vegetation, the climate, the root structure and water requirements.
WHEN TO PLANT
Plants in containers can be planted out into the garden at any time of the year, this is possible because the root-ball of the pants remains undisturbed when it is planted into soil, Evergreen trees and shrubs are best planted and transplanted during the rainy season, before transplanting and evergreen tree or shrub, remove half its leaves to prevent excessive moisture loss until the roots have had a chance to redevelop, Transplant shock can also be reduced by spraying with a solution such as Wilt-Pruf, which reduces transpiration through the leaves, it is a good idea, when transplanting trees and shrubs, to allow them in their new position to face in the same direction as they were facing before.
Bare-rooted trees and shrubs, usually deciduous, are best planted in late winter or spring, before their active growing season starts, before planting; it is advisable to soak their roots in a bucket of water and to cut back all damaged and broken roots to healthy tissue.
SOIL PREPARATION
· Before planting, make sure the soil is well drained: few plants will thrive in ground that remains waterlogged for any length of time. Dig a large, square hole, at least three times the size of the container, and break up the ground at the bottom to allow the roots to penetrate the crust, the soil in the container should be thoroughly wet before planting.
· Next, prepare the soil mixture in the hole, in general, the best mixture is one part compost, two parts soil from the hole, 60 g of 3:2:1 (28) SR general fertilizer and 60 g superphosphate or bone meal (or controlled-release plant fertilizer tablets like fleuron can be used instead) for acid-loving plants, use one part acid compost or peat moss (preferably imported peat) to two parts soil from the hole and 60 g bone meal.
· Make an opening in the prepared hole just a little larger than the plant’s container, remove the plant from the container, taking care not to disturb its roots, and place it in the hole, remember to position the plant at the same level as the surrounding soil line, should the plant appear to be root bound, before placing it in the hole tease open the perimeter roots at the bottom to encourage new growth.
Trenching
Plants such as sweet peas or liliums require significant depth for their roots, and the best way to achieve this is by bastard trenching:
· Mark out the area required with string.
· Divide this area into strips about a meter wide.
· Remove topsoil to a depth of about 250 mm in a trench about 300 mm across, and heap to one side of the bed.
· Dig over bottom soil, breaking it up and adding organic matter such as well-rotted kraal manure or compost, together with one handful of bone meal per running meter.
· When this section of trench is totally dug over, move your line another 300 mm and dig a second trench to a depth of 250mm, this time moving loosened soil into the first trench.
· Loosen bottom soil in second trench, again including your additives.
· At this point start your third trench, moving its topsoil into the second trench and so on, until the entire bed is trenched, and finally putting soil from your first trench onto the loosened base of the last trench.
Improving Your Soil
When cultivating the soil, it is important to improve its texture and quality on an on-going basis, organic matter acts as soil conditioner by improving the structure, drainage and aeration characteristics of the soil, however the food value of organic matter is low, although it does contain some necessary trace elements to ensure correct feeding of plants, chemical plant foods or fertilizers are necessary.
Soil Texture
The Size of the soil particles determines the soil particles determines the soil texture, be it gravel, coarse sand, fine, sand, silt, clay and organic matter, water is found in the spaces are large in sandy soils, water drains away quickly, in clay soils these spaces are smaller and overwatering fills them to the exclusion of air, causing water logging.
The addition of organic matter-compost, mushroom compost, peat and kraal manure helps bind sandy soil to enable it to retain moisture at the roots of plants, to break up clay soil, the long-term remedy is to add lots of organic matter, coarse sand and lime.
FERTILIZING
Nowadays, fertilizers are available in a wide selection of chemical and organic compounds, chemical fertilizers provide a high nutrient value, consisting of macro and micronutrients, and most are synthetically created with a salt base, macronutrients are those nutrients needed in larger amounts than the micronutrients and the presence or absence of any one of them has a detrimental effect on plant growth regulators in building chemical compounds in plant cells.
Organic plant foods however are naturally derived compounds, usually in liquid form and highly concentrated, containing macro and micronutrients as well as one or more growth stimulants.
Macronutrients:
The three major macronutrients, nitrogen (N), phosphorous (P) and potassium (K), are essential for all plant growth, Fertilizer labels show the percentages of these three primary macronutrients, for example 2:3:2 (22) is the ratio of N:P:K, with 22% available plant food and the remainder being carrier constituents. Nitrogen is essential to maintain healthy green leaf growth, phosphorous is required for good root development, and potassium encourages flower and fruit formation, secondary macronutrients are magnesium (Mg), Calcium (Ca) and sulphur (S).
Micronutrients:
Micronutrients are iron (Fe), zinc (ZN), manganese (Mn), boron (B), molybdenum (Mo), and copper (Cu), these are usually included in plant food formulations like Nitrosol, African Violet Food, Seagro, Supranure plus, Multi feed P, kelpak and Trellmix, plant foods are highly concentrated and should be used with care, follow directions for diluting with water before application, although they are usually indicated for pot plants, they can be beneficial for all plants.
Slow-release fertilizers:
Slow-release (SR) nitrogen fertilizers release nitrogen over a longer period, eliminating the risk of burning the plant with too much nitrogen and making it possible to fertilize fewer times in a season, nitrogen in a highly acceptable form is released by biological action, as and when the plant needs it, slow release nitrogen has made fertilizers more user-friendly. Example of these are 3:2:1 (28) SR for lawns and general fertilizing of shrubs, trees and climbers; 3:1:5 (22) for pot plants; and Supra 4:1:1 (81) for beautiful ferns and palms, All chemical fertilizers not containing slow release (SR) nitrogen need to be watered well after application to prevent plants from suffering chemical burn.
Applying fertilizers:
When fertilizing beds, sprinkle the recommended amount evenly over the surface, for roses, trees and shrubs, spread the fertilizer evenly over the whole surface, including the circle beneath the drip area of the branches, Even quicker results may be obtained by raking or watering the fertilizer into the soil, remember to follow instructions on the fertilizer container and to water well after each application for optimum results.
DIGGING GARDEN BEDS
Garden beds need to be dug over in preparation for new plantings of annuals, perennials, ground covers and vegetables to incorporate organic matter and fertilizer into the soil, it also helps to aerate the soil by improving the soil texture, the best time for digging beds in areas that experience heavy frost, is autumn, leaving the clods rough as they fall, this exposes the greatest surface to frosts and cold winds, ensuring an easy-to-work soil in the spring.
In spring, fork over the whole area, breaking up the clods and add a light dressing of 3:2:1 (28) SR fertilizer and well-sifted compost, In areas with Mind winters beds can be dug over throughout the year, Finally rake and level the whole bed before watering to settle the soil.
WATERING
It is important to check that your watering system is in good repair; leaks waste water and money, Modern plastic watering systems with tap connectors, hose joiners and push-pull connectors for attaching sprays and nozzles, such as the Gardena system, are easy to use and most effective, Gardena also offers a small, easy-to-program ‘computer’ for controlling your water system automatically, which can be screwed onto any tap, Among fittings available today is a wide variety of sprinklers and sprays designed for special work, including an excellent combined spray-and-feed fertilizing system, sprays with long handles specially designed for watering hanging baskets, and special hoses with holes for soaking areas.
Deep watering of plants is important, it is far better to water well occasionally than a little at a time; the aim is to encourage deep root growth rather than surface rooting.
Gardeners in summer-rainfall areas must remember that it is as important to water in winter as it is summer, although less frequently, winter winds can be as drying as summer heat, and winter rain is a rare occurrence in most parts of the country, In summer the best time for watering is in the early morning or late afternoon, as during the heat of the day the water evaporates too quickly to be able to soak into the ground satisfactorily, mulching around plants helps to retain moisture in the ground, mulch also reduces the soil temperature by preventing sunlight form reaching the soil, and so inhibits growth of weeds.
COMPOST MAKING
Part of your regular maintenance program, apart from tidying the garden and collecting fallen leaves, should be to turn the refuse into valuable compost, not one scrap of organic matter form your garden or kitchen should be wasted.
· Stack the compost material into an enclosure with openings at the sides for air to penetrate
· Turn the piled-up material once a week with a gardening fork to aerate it, compost decomposes faster in the middle, where it is hot and moist, than on the outside, so redistribute compost to achieve consistent decomposition.
· Water as needed; compost should be moist but not soggy.
· Scatter a handful of compost plant food like wonder 2:3:2 (22) or wonder organic fertilizer every time new material is added, to help speed up decomposition.
· A good mixture consists of dried and green material in equal parts; chop up large coarse pieces, as they decompose very slowly.
· Remember though that a poorly maintained compost heap will be slow to decompose, will be a breeding ground for flies and will give off an obnoxious odor.
· Today there are many aids to making compost, from commercially made bins, suitable for small and townhouse gardens, to special products that help break down the compost (compost activators) and even electric shredders that quickly chop up leaves and large pieces for composting.
PRUNING
At the end of winter when severe frosts are over, it is time to prune rose bushes and fruit trees, ornamental shrubs might also need attention, although these can mostly be pruned all year round as well.
Before attempting pruning, be sure to have the correct tools; a pair of secateurs, long-handled pruners, a good saw and gloves, Gardena supply most garden shops and nurseries with a wide range of necessary pruning equipment.
Why Prune?
· To form or shape a plant.
· To maintain healthy plants by removing dead, diseased or injured wood.
· To let in sufficient light and air, for maintaining an even balance of growth.
· To increase the quality or yield of flowers and fruit.
Things to remember when pruning
When pruning, whether it be roses or fruit trees, remember the following:
· All cuts should be clean and sharp with the minimum of bruising to the stem.
· Make cuts less than 10 mm above a strong leaf bud, at a downward angle, in order to prevent water remaining on the surface of the cut.
· Large cuts can be sealed with a tree sealer that sterilizes as it seals. It is not necessary to treat smaller cuts.
· Once pruning is completed, spray with lime sulphur or oleum to kill any scale or other insect pests still present.
· Fungus in the form of black spot and powdery mildew can be controlled by spraying with Bayleton-A, Funginex, Coppercount-N, etc.
Pruning all year round (especially evergreen shrubs
· Dead-head roses, agapanthus, daylilies, etc. to prevent seed setting, This encourages plants to produce more flowers.
· Shape trees by removing unwanted branches
· Trim and shape untidy hedges.
· Trim plants that are hanging over pathways. |
Annuals
