Billard's spirea

These plants grow well in sun or in partial shade. Usually they tolerate more sun and heat if given enough moisture; in partial or light shade they need less moisture.

Decidious have woody stems (i. e. tree trunk and branches) and are also called woody plants or trees. Leaves are normally broad, soft and thin.

The plant develops new leaves or needles every spring, which dropp off in autumn. Herbaceous plants can die completely in above ground section and grow back in the spring.

Plant can in otherwise appropriate environment survive cold down to - 23 °C.

Porous or dry soils are normally light and loose, there is no stagnant water but relatively quickly flows in deeper layers; such ground are more airy and warmer, yet drier and usually contain less humus and for such undergrowth it is often to for drought to appear (e. g. rockgardens, walls, by paths and roads, on gravel, also on gravel surface in towns and close to buildings ...), plants of such undergrowth need well-drained soil, they tolerate drought but cannot tolerate constant moisture or even flooding.

Woody plant, normally branched at the ground level into several side stems, usually lacks of a dominant stem. Tree top can be of different shapes, dense or thin, symetric or uneven. Most shrubs reach a height of 1 to 2 metres, but some can grow much higher (up to 8 m); some can grow into very low or carpet-like forms.