Every garden centre will currently bombard you with colourful displays of seed packets (figure 1). Each contains tiny grains of dormant life. Provided with water, warmth, suitable soil or compost and eventually light (figure 2) that resting grain will transform into the roots and shoots of a new plant.
Image 1: Racks of seed packets
Inside that seed cascades of genes trigger enzymes which release energy from stored starch and in some cases lipids. As a result, the seed coat opens and a root emerges which takes in supplies of water and nutrients. Shoots follow which grow upwards towards the light. They turn green as chlorophyll is manufactured and photosynthesis commences. At that point the seemingly inert grain becomes a self-sustaining living plant. Root and shoot growth result from active cell divisions with genetic controls determining the form and functions of each organ.
Image 2: Germinating seeds and the correct conditions
Each seed’s compliment of genes will determine what type of plant develops. But it is the environment provided by the gardener which determines the plant’s success. Careful and accurate husbandry results in succulent, health-promoting vegetables or colourful, vigorous flowers. Seedlings of some plants may be given nursery treatment before being placed into the garden’s big wide world. Providing protection in the early stages either in a green house or under cloches for many annual flowers and most vegetables boosts growth (figure 3) and eventually the quality of the produce.
Image 3: Legumes grown under protection
This does require time, skill and investment by the gardener. An alternative is purchasing seedlings from garden centres (figure 4). But an element of caution is required. These plants will have been raised under protection. Hence planting directly into the garden means still need care and attention. Frost protection and watering are essential, otherwise poor results may follow.
Image 4: Garden centre seedlings
Direct sowing seeds into garden soil is another alternative. Hardy vegetables and annual flowers may be cultured in this way. The requirements for success are a fertile soil with a fine tilth, that means it is free from stones and consists of uniform, aggregated particles allowing unimpeded movement of air and water.
Vegetables such as beetroot, carrots and parsnips will grow vigorously given these conditions. Hardy annuals such as African daisy, larkspur, love-in-the-mist, marigold and nasturtium will also thrive from direct sowings. Success in both garden departments depends on watering during dry spells and supplementary nutrition. Avoid nitrogenous fertilizers as these will encourage leaf growth whereas phosphate (P) and potassium (K) will promote root and flower formation.