The rose, botanically classified as a perennial woody shrub, is an ancient and popular flowering plant that has been cultivated for thousands of years. The question of what a rose “grows on” refers both to its physical, internal structure and its overall external shape or habit in the landscape. Understanding the rose begins by examining its foundational components, which provide the structure and support necessary for its celebrated blooms. This plant is a complex system of specialized parts, from its underground network to its flowering shoots.
Anatomy of the Rose Plant
The foundation of the rose plant is its root system, which consists of both thick anchor roots and fine, fibrous feeder roots. Anchor roots provide physical stability and store carbohydrates to fuel growth. Fibrous roots are responsible for the absorption of water and dissolved nutrients from the soil. Rising above the ground are the canes, the main woody stems and branches that form the structure of the bush and support the leaves and flowers.
Canes are composed of different types of wood, which is important for pruning and plant health. New wood is often pliable, displaying a reddish or green tint that signals active growth. Old wood becomes harder, thicker, and turns a gray or brown color, eventually becoming less productive. The leaves are characteristically pinnate, composed of multiple leaflets arranged along a central stalk. The sharp growths on the canes are technically prickles, not true thorns, as they arise from the outer layer of the stem.
Diverse Growth Habits
Roses exhibit a wide range of growth patterns, determining how they appear in a garden setting. The most common form is the shrub rose, which includes Hybrid Teas and Floribundas, characterized by an upright, bushy, and rounded shape. These varieties generally range from two to seven feet tall and are self-supporting, requiring no external structure. The bushy habit results from multiple canes emerging from the base, creating a dense plant suitable for hedging or as a stand-alone specimen.
Climbing roses have long, stiff canes, but they are not true vines that can attach themselves to a surface. They must be physically tied or trained onto a support structure like a trellis, arbor, or fence. When grown at an angle, these rigid canes produce lateral shoots that maximize bloom production. Miniature roses are small-scale versions of the larger shrub roses, typically staying under two feet tall with a compact form.
The groundcover rose has a low, spreading, and sprawling growth pattern. These varieties are wider than they are tall, often reaching over three feet across but staying under one-and-a-half feet in height. Groundcover types are valued for their ability to spread quickly and cover large areas, creating a carpet of continuous flowers.
The Importance of Rootstock and Grafting
Most hybrid roses sold commercially are created using a technique called grafting, which combines two different plants into a single specimen. This method involves joining a bud from the desired rose variety, known as the scion, onto the established root system of a separate, hardier plant, called the rootstock. The rootstock serves as the physical and biological foundation, providing a vigorous anchor, disease resistance, and adaptability to various soil types. Grafting allows growers to quickly propagate plants that are larger and bloom sooner than those grown on their own roots.
The point where the two plants are fused is called the graft union, often appearing as a knobby, swollen joint just above the roots. This union is a structurally significant area that dictates the overall hardiness of the rose and must be handled carefully when planting. If the rootstock becomes too vigorous, it can send up shoots from below the graft union, which are known as suckers. Suckers are genetically different from the desired upper part of the plant and must be removed completely at their base, or they will divert nutrients and eventually overwhelm the grafted rose.