Leaves are factories, which manufacture sugar, later converted into starch. Starch is the basic food of plants and is stored in fruits, stems, seeds, etc. The green material in the leaves or young stems called chlorophyll, uses water drawn from the roots and carbon dioxide absorbed (by stomata of leaves) from the atmosphere to form sugar. Since this production uses light (photo) energy from the sun, the process is called photosynthesis. For the gardener, however, leaves are a part of the attraction of a plant and in case of foliage plants they are centre stage!

Leaves can also absorb soluble nutrients when these are sprayed over them. Settling of dust on the leaf surface, apart from looking ungainly, reduces the absorption of light. Clean with a spray of water. Big leaves can also be cleaned with a cloth moistened with a light detergent.

Roots

Roots are the foundation of the plant, anchoring it stably in the soil. They are the principal raw material suppliers, and spread their "pipelines" underground, searching for nutrients. As a general rule, the root system stretches as deep and as wide underground as the portion of the plant above it. Tall trees thus have their roots going several metres deep-the deepest being the desert palm as it has to seek water from the far recesses of the soil.

Roots also breathe-just as every living cell does. The soil has enough intra, terrestrial oxygen to sustain the roots. This fact helps us to appreciate the need to make gardening soil sufficiently porous. Healthy rootlets are white in color. When rotted, they turn black. When rotting begins due to persistent water logging, growth becomes retarded and the plant becomes weak. If the roots dry out completely or remain waterlogged for a long time, the plants die.

Flowers

Flowers perform the sexual function of reproduction. Flowers can be male, female or bisexual. The display of color is perhaps their courtship dance.

Flowering in plants is very dependent on the amount of light and the length of the day. That is why summer blooms don't come to flower in winter (and vice versa) even if the plant grows. A good illustration of this fact is provided by chrysanthemum. While the plant thrives all through the year it only comes to bloom when the length of day and the duration of light is light.

Excess watering and nitrogen (see Fertilizers) can adversely affect flower development; and pruning at wrong times can play havoc with them.