Roses are prized for their beauty and fragrance, but they can sometimes face challenges that cause them to wilt or decline. Learning how to revive roses starts with successfully diagnosing the issue. In this article, we’ll explore common pests and issues that roses may encounter, signs indicating their poor health, and effective strategies to revive and restore these beloved flowers to their former glory.
Let’s dig in!
White Powder on Rose Leaves
Roses are particularly susceptible to powdery mildew—a fungus that happens when large temperature and humidity fluctuations occur. The fungus will drain nutrients from the leaves and could cause your roses to struggle or wilt.
If you notice white powdery mildew, revive your roses by spraying off the leaves and treating them with a fungicide. Consider trimming back your roses or spacing the plants to prevent cross-contamination. Sprinkling garden sulfur can also help prevent mildew growth.
Browning Rose Leaf Edges
If your roses are struggling and you notice brown edges around the leaves, there are a few potential causes.
First, consider the weather. Has it been hotter and sunnier than usual? While roses love the sun, extreme exposure can scorch the leaves. In this scenario, the leaves will likely be crispy to the touch. Thoroughly water your roses and consider putting up a barrier if the weather continues.
Another common cause is an excess of salt in the soil. If you’ve been watering your roses with treated water, consider switching to rainwater harvesting. Revive the roses with a thorough watering to wash excess salt away.
Brown leaves can also indicate a fungal or pest infection. Take some time to examine the stems and blooms for other signs to diagnose the cause.
Yellowing Rose Leaves
Yellowing rose leaves can also indicate a few different issues.
The most common cause is a nutrient deficiency:
- Nitrogen – if the yellowing starts with older leaves and progresses to new growth, it’s likely a nitrogen deficiency.
- Magnesium – if the leaves are yellowing around the edges and progressing toward the center, it’s likely magnesium.
- Iron – if the leaf’s veins are green and everything else is yellowing, it’s likely iron.
Adding a nutrient-rich fertilizer will help revive your roses. However, if you regularly treat or fertilize your roses and notice this problem, the opposite could be true. Roses exhibit signs of stress when they’re overfertilized or exposed to too many pest-resistant chemicals. Reassess your treatment schedule.
Rose Plant Pest Invasions
There are a few common pests that love to attack roses. The most common is the aphid.
These tiny green insects munch on the leaves and detract nutrients, which could lead to malnourishment over time. If you notice them on your roses, wash them away with a hose. Introducing natural predators (ladybugs, for example) to your garden will help keep them away.
Spider mites are another common invader in the garden. If you notice tiny bugs or gray speckles on your leaves, it’s likely spider mites. Wash them off with a hose or warm, soapy water.
Thrips are another common rose plant pest, but these invaders attack the blooms. Treat the plant with insecticide if you notice brown edges on your rose petals.
Black Spots on Roses
Black spots on rose leaves often indicate a fungal infection. These spots often have yellow edges. Trim away the infected leaves and move them far from your garden. Act quickly, and introduce garden sulfur to help prevent the spread.
If you notice black spots on the stem, it indicates rot in the wood. Prune back these areas and move the infected portion away from the plant.
Black spots can also indicate other issues, such as stress. You may notice these spots appear after a storm or late-season frost. Ensure your rose is in the right location with plenty of sun and water regularly to minimize stress.
When diagnosing your roses, looking at the cane and stem system is important. If the cane is dying or failing to thrive, evaluate your watering schedule and soil quality. If the soil is draining too quickly, your roses may be underwatered. Irrigate the area or mulch the roots to help.
Overfertilization can also impact the cane and root health, though you’ll see signs on the leaves as well. Cut back the damaged wood and reassess your fertilization efforts.
Cut the cane in the dead or dying section and check to see if there are holes inside. Cane borers are an insect that burrows through the cane during the dormant season. Cut back the affected area to revive your roses.
Finally, if you notice a large growth at the base of the plant with a wart-like or tumor-like appearance, it’s too late to save your roses. This issue is called Crown Gall. It’s an invasive bacteria that will live in the soil and infect future plants. Dig up the entire rose plant and burn it, then leave the soil unplanted for 5-7 years.
The photo featured at the top of this post is © JHVEPhoto/Shutterstock.com
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