Root profiles to learn for rose growers

Added on 27 October 2020

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Taking care of a rose's roots pays off in the health and longevity of the plant. While roots bring in nutrients and stabilize the bush, they can also introduce disease. Not all roses grow on their own roots, however. With the surge in popularity of hybrid tea roses, beginning in the 1940s, most of the new varieties were grafted onto "Dr. Huey," a hardier rootstock. Recently, in a reverse trend, growers have been moving many roses back to their own roots.

Root Profile

Basically, the roots of every rose contain two types of structures, each with its own function. The thick, strong anchor roots keep the rosebush upright as it grows and also store nutrients for the dormant winter season. A second thin and hair-like root type, called feeder roots, absorb nutrients in the soil as they become available for the plant's immediate use. If the rose has been grafted, the shank of the rootstock rose leads up from the roots to the bud union, where the canes of the desired variety have been spliced onto the rootstock. The canes, or main branches, of an own-root bush emerge directly from the root mass.

Grafted Rootstocks

Rose breeders do not agree on the supremacy of grafted or own-root roses. Advantages and disadvantages exist for both. Grafting began in order to compensate for the early hybrid teas' lack of vigor. The grafted bushes were bred for cutting, giving the roses long, gangly stems. Therefore, these hybrids are often delegated to the back of beds, so lusher plants can be planted in front to hide the roses' bare spots. When this happens, it may deprive them of adequate air circulation and could result in contracting a fungal disease. If the graft dies, you will end up with "Dr. Huey," a less desirable specimen. One advantage of a grafted rose, however, is that greenhouse production time is less, making the plant cheaper for the gardener.

A Rose's Own Roots

For the past 30 years, some breeders have been advocating growing roses on their own roots. Own-root climbers and floribundas have recently been introduced on the market. One of the largest rose producers in the West, Jackson & Perkins, has led this movement. They explain that the gene pool for roses has so improved in vigor, disease resistance and production that roses being developed now will be able to flourish on their own roots. Own-root rosebushes tend to have rounder shapes and, if the plant should freeze to the ground, the emerging new growth will be true to the variety. One disadvantage remains, though. These roses may take up to three years to be market-ready, so the resulting price can be three times that of grafted roses.

Giving Roots a Good Start

When planting new roses where other rosebushes have grown for five or more years, begin by adding much organic matter, as the soil has likely been exhausted. If purchasing an economical bare-root rose to plant in late winter or early spring, look for fresh-looking, well-formed roots, neither slimy nor dry and withered. Before planting, soak the roots for 24 hours in a bucket of water. Dig a large hole, and form a cone of soil in the center to spread the roots over. First, trim off any damaged roots. If you are planting a grafted rose, place the bud union of the plant right at soil level. Finally, fill the hole in with soil, and water well.

Source: SFGATE