FAQ

Sowing Tips | Planting | Soil | Maintenance

Sowing Tips

Seeds need a good balance of moisture and air, plus warmth, to germinate freely and strongly. The old adage has it 'sow dry, plant wet', but dryness of the soil in sowing refers to surface only.

Sow neither too shallowly when seeds remain unmoistened, nor too deeply when they suffer from oxygen starvation. A good rule of thumb is to sow at two to three times the broadest diameter of the seed. In sandy, light soils, however, seeds can be placed a little more deeply; in heavy, dense soils a little more shallowly. When it can be easily located, there is some advantage in placing a seed with the hilum or 'eye' uppermost.

On sand, chalk or silty soils, liable to dry out quickly, cover seeds with moist peat or old compost rubbed through a fine riddle. Practise the same trick on soils that form a crust when they dry out after rain.

On clay soils and wet soils, cover seeds with coarse sand or vermiculite, at least when sowing early in the year.

Dress seeds with a suitable combined fungicidal and insecticidal seed dressing. The cost is very trivial, and prevents losses from soil-borne diseases such as damping-off and stemrot of seedlings, and from insect pests such as wireworms.

Apply base fertilisers, compounded to provide a balance of plant nutrients, at least seven to ten days before sowing or planting in spring.

Planting and Fertilising

Remember that the purpose of fertilisers is primarily and overwhelmingly to provide plants with essential nutrients for growth and development. They are concentrated, and may be of inorganic (chemical) or organic (plant or animal) origin. Too much at any one time can do harm, both to soils and plants.

There are 12 to 14 essential mineral nutrients that plants need from the soil, usually divided into (a) the major elements nitrogen, phosphorus, potassium, calcium, magnesium, sulphur and iron; (b) the trace elements-manganese, boron, zinc, copper, molybdenum, and possibly sodium and chlorine, according to the relative amounts in which they are required.

In nature the sources of these nutrients are the mineral rock fragments and the organic matter of which soils are formed. They are available to plant roots by the physical and chemical reactions that take place in the soil and by the activities of certain forms of soil life, particularly soil bacteria and micro-organisms, entering the soil moisture in the form of soluble nutrient salts. What is not immediately taken up by plants may be stored in the soil or lost in drainage.

Under cultivation, soils lose their nutrient salts more quickly than they are replaced naturally, both in the plants grown and in the more rapid penetration of rains and loss of soil moisture in drainage. Humus-forming organic matter in the form of manure, plant and animal remains puts back some of the nutrients, but it is even more important as the base of biochemical soil activity and the means by which soluble mineral elements may be retained more strongly in the soil.

Soil

The readiness with which a soil absorbs and retains sun heat has a profound effect upon seed germination, root activity and subsequent growth. This is chiefly affected by two things -porosity and colour. The more porous a soil, the more freely air circulates through it, and the more quickly it reacts to sun heat and atmospheric temperatures. Thus light, sandy, gravely or chalky soils of open texture warm up relatively quickly in spring, permitting an earlier start to be made with sowings, plantings and croppings. The heavier and more clayey the soil, the more moisture it contains, and the longer it takes to warm. The gardener with a heavy, moist soil may therefore find himself one to three weeks behind his fellow on a light, porous soil.

Colour affects soil temperatures in that the darker the colour, the more completely it absorbs the sun's heat rays, and the more slowly it loses their warmth. A dark-coloured soil not only absorbs sun heat quickly in the early spring, but also retains it to lengthen the autumn growing period. Ideally, the best soils are those which are porous and dark by reason of the presence of decomposing, humus-forming matter. Since the latter also contributes to a better soil structure and more openness, most soils can be ameliorated by its addition in the form of regular organic manuring.

And having taken all these weighty matters into account, there is still the garden's own micro-climate to be considered. As your garden evolves and becomes planted with its permanent inhabitants, it acquires a climate of its own. A screen or a hedge here will give shelter and slightly raised temperatures in its lee, permitting the earlier planting or cropping of certain plants. Some parts will get more sun than others.

Maintenance

The higher your garden, the colder and more exposed it will be, which will make for a late spring and an early autumn, though the full effect of altitude may be modified by the lie or aspect of the land, and its height relative to surrounding land. Light intensity tends to increase with latitude, making for good and rapid growth when temperatures are in step.

If your garden faces south to south-west, it receives much sun, both daily and seasonally, which makes for extended growth. The garden is well warmed, and so can be cultivated early in the spring, and autumn tends to come late. With a northerly or easterly aspect, the daily duration of sun is shortened at the approach of sunset, and light duration and intensity diminished. This delays warming-up of the soil in spring, and fosters greater susceptibility to low temperatures.

This is important because of its effect on air currents. If your garden lies in a depression of ground, cold air will tend to gravitate to it. It will then be susceptible to spring, autumn and winter frosts to a greater degree than the higher surrounding land. The same effect also results when cold air flowing from higher ground is trapped by walls, fences, buildings or hedges placed across the slope, so that it cannot escape to lower ground.