This is the first spring sprout of the conifers (firs, pines). The buds open and the protecting involucres come off the bud edges. The involucres either stick to the buds or fall down. The needles are not yet expanded.

The first regular surfaces of leaves become visible in three places on the observed plant. The first leaf of a plant has pushed out of the bud up to its leaf stalk (petiole). Larch: The appearance of the first fine pale green needles, which are arranged in fascicles when the buds burst, corresponds to the leaf unfolding. Mountain ash: 'Leaf unfolding' has starts as soon as the pinnules of the first leaves have completely unfolded but have not yet reached their entire size.

Almost regularly the first sprouts of oakes and mountain ashes are followed by a second sprout, the 'St. John's sprout'. Buds that are already developed for the next year are caused to sprout prematurely by weather factors. These second sprouts can be recognised by their fresh colour. The state of the first leaf unfolding is repeated: The first leaves of the sprout have their typical forms but not yet the final size of the full-developed leaves.

The first regular flowers have opend in three places of the observed plants. The anthers of anemophilous plants are scattering pollen. If there is strong wind, the first scattering of pollen can easily be recognized in all anemophilous plants. If calm is prevailing, the observer should shake the branches in order to find out whether the first flowering has occurred. In trees bearing catkins this phase can easily be recognized because the catkins turn round their longitudinal axis when opening and change their colour. Common Beech: Concerning the date of 'beginning of flowering' it must be considered that the beech usually does not flower each year. Locust and alpine currant: The 'beginning of flowering' should be recorded when the first few flowers at the base of three inflorescences on the observed tree have opened. Willows: The stage when the buds have come out of the brown protective scale leaves (volucra) and show their well known silver-grey hairs should not be considered as the beginning of flowering. At the 'begin of flowering' the golden yellow stamens of the male flowers should be visible.

This is the phase in which more than half of the blossoms of the observed plant have opened.

The first fruits have ripened in three places of the observed plant. Succulent fruits have entirely taken on their definite colour; capsular fruits burst out of the hulls (without external influence). Common oak and hazelnut: Concerning the ripeness of fruits it must be considered that acorns/hazels which are destroyed by vermin and have fallen down prematurely are not noted as ripe. Mountain ash: During the time in question the berries have to be observed very carefully to note for the first time the day when the coral red colour of the berries change to their last shade. Elder: 'First ripe fruits' should be recorded when the majoroty of the berries of three inflorescences have become ripe up to the edge of the inflorescence, i.e. that they have reached their definite colour.

More than half of the leaves (>50%) of the observed plant have changed their colour, including those leaves which have fallen all at once in large quantities. This regular colouring of the leaves in autumn is caused by low temperatures. It must be distinguished from the withering of leaves which entails their discolouring due to drought during the summer months. This so-called drought-discolouring of leaves which may already occur in July in dry years and in dry places must be observed seperately. The phase designation 'autumn colouring' should be applied by analogy to the turning of the needles.

More than half of leafs (>50%) of the observed plant have fallen. The phase designation should be applied by analogy to the fall of the needles.