Dead-heading: The removal of faded blooms from flowering plants. It is carried out to improve the plant’s appearance and to prevent seed from setting which, in many cases, encouraging further flowering.
pH: A scale describing the degree of acidity of a substance; it is based on the negative logarithm index of hydrogen ion concentration. It is of special relevance to soils. pH 7.0 represents neutral conditions; pH values below this indicate acidity, and those above it, alkalinity. Soil pH may be measured by simple pH tests, or with a pH meter.
Pricking out: The operation of transferring very young seedlings from the site where they have germinated to other containers or beds, in order to provide more space for growth. Great care should be taken to handle only the seed leaves and to ensure that the roots are mostly intact and then settled in gently, first with a dibber and secondly by watering-in.
Restricted fruits: These are fruit trees - such as apples, pears and cherries - which are carefully pruned into various shapes, to keep them small and to encourage the highest yield for the space they occupy. Examples of shapes used are: cordon, fan, and espalier. These forms require initial training along supports. If kept below 1.8m (6ft) in height, they are easier to pick than conventional, unrestricted trees. Open, unsupported trees can also be restricted slightly, into pyramidal, or spindlebush forms. Restricted friuts are generally pruned more in summer than winter.