Roses: Three Common Problems

Like any plant, roses are susceptible to many pests and diseases. They’re also more prone to weather damage than many garden plants because of their tender blooms and delicate new growth. Recognizing some of these issues and knowing how to remedy them can help you limit how far they spread and how long they affect your plants.

In this article, we’ll cover three common problems, the causes, and most importantly, the fixes.

Rose Dieback

Dieback is not uncommon in roses, and it is often a combination of factors that cause it. The main culprits are the weather and difficult growing conditions, both of which can unduly stress a rose plant and leave it more susceptible to problems.

Look for stems that darken, shrivel, or turn brown, usually working back from the tip, often with a clear line between dead and healthy tissue.

It’s important to catch dieback early. In many cases, roses can seal off damage and limit it to a few branches, or parts of a branch. In more severe cases, however, it can spread to the whole plant and lead to premature death, often because of compounding disease factors.

Stopping It Early

Using several prevention methods is the best way to keep dieback under control.

• Check after severe weather. After frosts, heavy rain, wind, or extreme heat, look over your rose thoroughly for split stems, damaged leaves, or early browning. Carefully remove affected sections, cutting back to healthy wood about ¼ inch (6mm) above a node so the plant can seal the wound properly. Healthy stems have white or cream pith in the center, so if it’s brown, keep cutting back.
• Prune well, and at the right times of year. Whenever possible, avoid pruning in periods of cold and extreme heat, as both reduce the chance of the cut sealing properly. Always prune with sharp, sanitized tools, and angle the cut away from the bud so water runs off.
• Fertilize regularly. A healthy plant is much better equipped to fight pests and diseases and to recover after inclement weather. Keep the soil slightly acidic, around pH 6.0–6.5, and feed at minimum every spring, mulching to conserve water through the summer. Stop feeding by late summer, as late fertilizing pushes tender new growth that frost can damage.
• Remove dead wood and stems regularly. Leaving them on the plant creates easy entry points for fungi and pests.

Rose Blindness

Rose blindness is a physiological disorder in which a shoot looks normal but fails to form a flower bud at its tip. Sometimes, a bud forms but is empty.

A rose plant can appear perfectly healthy, with vigorous growth and no signs of disease, and still not flower. The exact cause isn't fully understood, but contributors include too much shade, frost, or wind, damaging a bud or tip.

Look for a stem that appears normal but stops short, or ends in a tiny cluster of leaves with no bud. A blind shoot is a cosmetic issue rather than a disease, and it doesn’t harm the rest of the plant.

Managing Rose Blindness

A blind shoot won’t flower on its own, but you can prompt new growth. Cut it back to a strong, healthy, outward-facing bud located just above a leaf set with five leaflets. You will get fresh growth from that bud, which will very often produce a successful bloom.

Removing older wood generally encourages better flowering in repeat-flowering roses. This is best done as part of the more aggressive annual prune in late winter or early spring, just before growth starts. Once-blooming roses flower on old wood and are best pruned after they flower.

It’s also worth checking your roses’ growing conditions. Make sure they’re receiving the sunlight they need, and maintain or improve the soil with fertilizer and mulch. If conditions are too far from what they prefer, consider moving your roses while they’re dormant.

Replant Disease

Replant disease is poorly understood. It occurs when a plant of the same type, or sometimes the same family, is grown in soil where another previously grew. Roses and other members of the rose family, including apples, cherries, plums, and pears, can all trigger it. It usually builds up over years of growing roses in the same spot.

Roses are perhaps the most affected. New plants struggle to establish, often show poor or stunted growth, and lose many of their fine feeder roots, limiting their ability to grow and store energy.

Fixing the Problem

The simplest fix is to plant your new rose somewhere else, or to put something unrelated in the old spot for a few years. If that isn’t an option, the fix is straightforward but labor-intensive. Dig out the soil in an area a few inches wider than the roots’ spread, usually a hole around 60cm (2 ft) across and 45cm (18 in) deep, and replace it with soil from elsewhere in the garden, or with a mix of fresh soil and compost. Don’t reuse the old soil for other roses or add it to your compost. Spread it somewhere roses won’t grow.

The cause is thought to be a build-up of harmful soil organisms, so adding beneficial mycorrhizal fungi can help. Products are available in sachets that you sprinkle into the planting hole.

Wrapping Up

Roses are beautiful but demanding plants, and their problems aren’t always obvious. Checking your plants regularly, especially after severe weather, will help you catch most problems early.

A steady routine of pruning, fertilizing, mulching, and watering keeps them healthy enough to resist common pests and problems, and gives them the best chance of recovering from the ones you can’t prevent.