Vegetative growth includes:

Stem. The stem consists of alternating nodes and internodes. Several nodes and internodes remain condensed underground, forming the crown (Figure 5). Above the crown, internodes elongate resulting in a stem length of 2.5 m or more under favorable conditions.

The lower nodes of the stem form lateral branches.The lateral branches may develop into tillers which are like full maize plants (Figure 5). Often, tillers do not have ears and are shorter than the main stem

In the lowland tropics, tillers rarely form, or if they do, rarely grow to full height.

The upper nodes develop lateral branches that become either functional or rudimentary ear shoots. All branches form terminal inflorescenses, which can be male (tassels) or female (ear shoots).

The growing point is at the tip of the stem (Figure 6). It remains underground for the first 3-4 weeks after planting. If the plant breaks off at ground level when the growing point is underground, a new plant can still regenerate. However, a plant that breaks below the growing point does not regenerate.

Leaves. A single leaf grows from each node. The leaves grow from opposite sides of the plant in an alternating pattern. Each leaf consists of leaf sheath, leaf blade, and collar (Figure 7).

The collar is a distinct joint which marks the point of extension of leaf blade from the stem. The appearance of the collar indicates that a leaf is fully extended. The leaf is connected to the stem below the collar, where the leaf sheath is attached to the node. Leaf sheaths support the plant before and during elongation of internodes.

All leaves are initiated within the first 4-5 weeks after planting. As the internodes elongate, a 'new' leaf emerges from the whorl once every 3 days (depending on the temerature), with a total of 16-23 leaves, depending on genotype and environment (specifically daylength and temperature).

A new leaf appears about every five days in cooler, highland environments.

The first leaf has a rounded tip; all subsequent leaves are pointed. The first 4-7 leaves decay and drop-off, and are not usually identifiable from 4-5 weeks after planting. The last leaf emerges shortly before tasseling.

Number of leaves is generally used to describe different stages of vegetative growth (Vn). For example, the 10-leaf stage is V10.

Although the convention is to count the number of fully extended leaves (leaves showing collars), it may be easier to count visible leaf tips. Also, number of visible leaf tips is a linear function of accumulated heat units from time of sowing, whereas appearance of leaf collars is not linearly related to heat units.

Roots. Roots originating from the stem tissue are called adventitious roots. They grow from the nodes that constitute the crown. Adventitious roots also grow from successive nodes near the ground (Figure 8), and are called brace roots. Most brace roots form after tasseling, and concentrate in the topsoil.

By the 8th week, the root system may be well developed, extending into the area between rows and reaching 45 cm depth. Cultivation between the rows at this stage can damage the plants.

Roots grow laterally in the upper soil and then turn vertically downwards (Figure 9).As the plant grows, individual roots may reach a depth of 2.5 m in good soil.