How to Grow Organic Roses

Every flower gardener can appreciate the classic beauty and symbolism of the rose, but more gardeners are learning that the conventional florist trade uses toxic chemicals to produce perfect bouquets. Fortunately, rose culture has been around far longer than chemical herbicides and pesticides, so organic gardeners can achieve a vibrant rose garden using natural methods.

Rose Varieties

Many gardeners picture the hybrid tea rose when thinking of the image of an ideal rose. Their large, perfectly formed flowers are striking, but the new rose gardener may wish to consider hardy heirloom varieties that grow on their own rootstock. Although many heirloom roses only bloom once a year, this profusion of blossoms may be preferable to the stingy production of hybrid tea roses.

‘Variegata di Bologna’ is a bourbon rose that resembles a camellia bush, with more than 60 crimson and white-splashed petals per flower. ‘Mutabilis’ is a China rose that mirrors the sky at sunset with copper and flame accents. Gallica roses like ‘Apothecary’s Rose’ date back to the 12th century or earlier, a testament to their hardiness.

Rose Fertilizer

Roses are heavy feeders, so the compost application that satisfies most other perennials in the organic garden won’t be enough to fertilize the high-performing rose bush. Fishmeal, dried blood, and cottonseed meal are two excellent sources of nitrogen for roses, ensuring healthy leaf production. An application of bone meal at planting time provides phosphorus for root growth. Finally, greensand and phosphate rock help ever blooming roses keep up the flower show.

Rose Pests

The list of pests that relish tender rose buds, leaves, and stems is long, but a healthy rose bush can survive most insect attacks with little more than some aesthetic damage. Aphids can seemingly appear out of nowhere in the spring, clustering on the new growth tips of the plant. Interplant your roses with sweet alyssum to hide gangly canes and encourage beneficial insect predators like lacewings and ladybugs. Knock survivors off with a blast of water.

Japanese beetles feast on roses in the summer, after their grubs have eaten their fill in the lawn. Control them with a neem-containing spray, or use a scented lure trap.

Rose Diseases

Black spot and powdery mildew are the two most common diseases that plague rose gardeners. Experienced organic gardeners expect to deal with these diseases at some point in the plant’s lifetime, and practice preventative measures as the first line of defense.

Black spot appears as blackened patches on the leaves surrounded by yellowish margins. The disease spreads quickly, and can defoliate an entire rose bush in a matter of weeks. Utilize proper pruning methods to improve air circulation in the rose plant. Apply an organic sulfur spray to the tops and bottoms of leaves. Gardeners must remove and destroy any affected leaves, especially leaves that remain on the ground at the end of the growing season, harboring spores that renew the disease cycle the following spring.

Powdery mildew is common in humid conditions or after prolonged periods of rain. Therefore, the gardener must prevent overhead watering that permits fungal spores to spread from leaf to leaf. Organic sprays or powders containing copper or sulfur can control mildew in roses, but consider replacing a rose plant plagued with disease with a hardier variety.