9 Reasons The Leaves on Your Roses Are Turning Yellow
Are your rose leaves turning yellow and you don’t know why? There are multiple reasons leaves turn yellow, and some of them are easy to fix. In this article, hobby gardener and rose enthusiast Danielle Sherwood explains the most common reasons you might see yellow rose leaves, and what you should do to address it!
If you’ve fallen in love with roses, you might worry when their former glossy green leaves start to look pale and yellow. Don’t worry! Yellowing leaves are not usually life-threatening to your rose. A quick examination can often tell you what you’re dealing with.
There are multiple factors that can impact the color of the foliage on your garden-grown roses. The good news is that many of the issues that may be causing this problem are easily treatable and preventable.
With a bit of knowledge about your climate, your soil, and prevalent rose bush pests, you can solve the mystery of what’s ailing your plants. Let’s dig into the most common reasons rose leaves turn yellow, and what you can do about it!
Too Much Shade
Most roses need 6-8 hours of direct sunlight per day to thrive and produce healthy green leaves. If your plant is shaded by a canopy of surrounding plants, its leaves may begin to yellow.
Sometimes, the dense foliage at the top of a rose bush is shading the lower and interior leaves, causing them to yellow and fall off.
Figure out what’s blocking the sunlight and trim back surrounding plants as needed. If the rose shrub itself is too dense, get out your pruners and trim it back a bit to allow more airflow and sun to reach the interior of the plant.
If you determine that you need to move your rose to a sunnier location, wait until early spring when once dormant. This will give it time to acclimate to its new digs.
Too Much Water
Roses like to dry out completely between waterings. When overwatered, the roots can become soggy and rot. This prevents roots from absorbing nutrients and needed oxygen, causing the entire plant to weaken and droop.
If your soil is waterlogged, your plant is likely wilting. You are also likely see leaves turning yellow and dropping from the plant.
Sometimes, rain and lack of drainage cause boggy soil and yellow leaves. In this case, you’ll need to amend your soil a bit to provide some air.
Water deeply and infrequently. Mature roses need 2-4 gallons (depending on the size of your rose bush) of water, once a week. Before watering, push your fingers into the soil a bit. If the top 1-2 inches aren’t completely dry, wait to water.
If the problem is lots of rain rather than watering, you can still help out by improving soil drainage. Amend the soil by mixing in 3-4 inches of organic compost, shredded bark, aged manure, or leaf mold. All of these will add more air pockets and circulation to wet, compacted soil, allowing your rose to breathe again!
The problem could also be a lack of water! Drought conditions or underwatering can cause rose leaves to turn yellow and the entire plant to wilt. Roses need deep, weekly waterings from you or the rain to keep them healthy and blooming,
During drought, locations that expose your rose to drying winds compound the problem by robbing your plant and the soil of adequate moisture.
Drought damage often appears as yellow leaves with brown edges. Potted plants are particularly susceptible as they dry out more quickly.
During drought conditions, try increasing your watering to twice a week to see if your roses perk up. Make sure to give a good, deep soak by leaving the hose at the base of the plant for 10-15 minutes.
Rejuvenate potted plants by placing the entire container into a larger bucket of water for a few hours. This will let the thirsty roots soak up the water from the bottom and rehydrate quickly.
For all plants, mulch is the best remedy to retain moisture in drought. Apply a thick layer of cedar wood mulch, compost, or leaf mold around the base of your plants. The mulch will prevent water runoff and evaporation, keeping your roses hydrated and happy!
Cold weather can hurt your roses during the winter without proper overwintering care. On the opposite end, too much heat can cause a completely different set of problems during the summer.
Roses adore the sun, but they get grumpy when temperatures rise above 85 degrees Fahrenheit, especially after transplanting. Too much heat causes small bloom size (or dropping blooms), droopy plants, and yellow leaves with brown tips.
Too much heat impacts essential processes the rose uses to store energy and produce healthy flowers and foliage. Consistent high heat (above 95 degrees Fahrenheit) hastens evaporation of moisture from leaves, slows photosynthesis, and depletes sugars needed for growth.
Some rose varieties can handle more heat than others. When buying, always check to make sure your rose is adapted well for your hardiness zone.
Keep your roses cooler in warm climates by choosing a location with morning sun and some afternoon shade. This will protect them from sun scorch and overheating during the hottest part of the day.
If you don’t have a spot with afternoon shade, consider using shade cloth or umbrellas to protect them for the hottest part of the day. Remember to remove the protection in the evening so your plants get adequate airflow and sunlight come morning.
Mulch your plants with a layer of compost or wood chips to keep the roots shaded and cool. Mulching keeps moisture in the soil, providing strength to withstand the heat.
If you see leaves with irregular yellow patterns and splotches, a foliar disease might be the culprit. Two common rose diseases, black spot and rose mosaic, cause yellow leaves that drop off the plant.
Black spot looks like irregular shaped black or brown splotches on the leaves, surrounded by yellow halos. It’s caused by the fungus Diplocarpon rosae, which thrives in wet, humid conditions. You’ll often see it appear during the cool temperatures of early spring. It usually begins on the lower leaves of the shrub and works its way up.
When left untreated, black spot will infect the canes, leaving rusty brown patches. It spreads from plant to plant via the wind, water, and infected leaves.
Rose Mosaic is a virus recognizable by the bright yellow mottled leaves, often with interesting swirled, spotted or zig zag patterns. Rose mosaic stunts plant growth and reduces bloom. It only spreads to new plants via grafting or budding (to combine two rose varieties), so you don’t need to worry about its spread in your garden.
There is no cure for black spot or rose mosaic. However, neither has to mean the death of your rose. When dealing with black spot, your goal is to prevent spread. Remove all infected foliage. Clear away any plant debris from surrounding soil and throw it away. Always disinfect your pruners after using them on diseased plants.
Prevent the wet conditions that encourage spores to grow by watering at the base, rather than on the leaves of the plant. Make sure to provide adequate airflow and sunlight so they can dry out between waterings.
As a preventative measure, try using this homemade baking soda spray to avoid future infection: Mix 2 teaspoons baking soda and 2 teaspoons vegetable oil in 1 gallon water. Spray thoroughly.
Rose mosaic can be lived with and won’t spread to your other plants. However, if your rose is no longer blooming or only producing distorted buds, it’s best to remove and replace the plant.
Iron deficiency is probable when leaves are pale yellow, but the veins are still green. The problem will strike the top leaves first and work its way down. This leaf yellowing is called Chlorosis. The problem could be a lack of iron, or soil that is too alkaline. When soil pH is above 6.5, rose roots can’t access the iron they need from the soil.
Nitrogen deficiency causes uniform, light yellow-green leaves that start at the bottom and work their way up. The leaves will get more yellow as time goes on. Eventually, plant growth will be stunted and you’ll notice spindly stems. When soil is too acidic (pH below 6), the rose roots can’t access needed nitrogen.
The surefire way to know what you’re dealing with is to test your soil with a simple kit. The soil kit will tell you if your soil is too alkaline (above 6.5) too acidic (below 6), or just lacking in necessary nutrients.
If you need to increase acidity, you can add organic compost, pine needles, or a premade product. To address iron deficiency, you can amend the soil with a liquid chelated iron product.
If your soil is too acidic, use a lime product, which will make the soil more alkaline. If you need to add nitrogen only, consider working some blood meal or your morning coffee grounds into the soil. Both will give a boost of nitrogen and help encourage bloom production.
Too Much Fertilizer
If you’re tempted to just dump a ton of fertilizer on your roses and wish for the best, not too fast! Too much fertilizer can cause yellow leaves too, and is especially damaging for young roses.
Adding too much fertilizer can kill off beneficial bacteria in the soil that are essential for your roses’ health. This is especially true for synthetic fertilizers. When there is an excess of nutrients like nitrogen (or the plant is in its first year and not yet mature enough to handle it), the roots will burn, leading to poor growth and yellow or brown leaves.
Never fertilize newly planted, young roses. Let their root systems develop first to avoid root burn. Opt for organic fertilizers like compost, manure or premade alfalfa and seaweed-based products over synthetics to maintain soil health whenever possible.
Apply a fertilizer when your roses leaf out in spring, once in midsummer, and again before last fall flush. If your soil is healthy, that’s all you need!
Spider mites are tiny, pesky bugs that are difficult to spot. They usually prefer hot, dry weather. They cause yellow and bronze colored leaves. Spider mites love thirsty, heat stressed plants.
The best way to attack spider mites is to knock them off manually with a strong spray from your hose. Make sure to hit the undersides of the leaves!
Keep them away by making sure your plants stay well-hydrated. Some evidence shows that misting leaves each morning with cold water can keep them at bay once removed.
Avoid use of synthetic pesticides as these will also kill off the spider mites’ predators (lacewings, predatory mites, pirate bugs). The spider mites inevitably come back, but you’ll have killed off their natural enemies. This starts a constant cycle of needing to spray pesticides in the garden once the natural biodiversity has been disturbed.
Hose off the spider mites as much as possible, and try to tolerate the infestation until their predators take care of them for you. This might take a couple of weeks.
If the new leaves on your rose are unusually small, yellow, and strangely shaped, the plant might have been the victim of herbicide damage. Other symptoms are twisted leaves and deformed buds.
Likely causes are glyphosate containing products like Roundup, or broad-leaf herbicides like the weed and feed often used on lawns. A breeze can cause these weed killers to drift over to your roses, potentially causing permanent damage.
If you’ve never used a weed-killing chemical, a neighbor’s spray might have breached the borders of your garden.
Some roses will die after herbicide exposure. Others can recover slowly. You just have to wait and see. Do not fertilize them until they show normal growth as this can cause further stress. In the meantime, make sure your rose is well-watered. It might have a weak season and come back strong next year.
To prevent herbicide damage, never use products containing glyphosate in your garden. Manually pull weeds near roses. Use mulch and desirable groundcovers to decrease weed growth.
As all weed killers can drift over to roses, avoid them if possible. If you do choose to use chemical weed control, exercise extreme caution to prevent harm to you, your roses, children, wildlife and pets.
Yellow leaves are usually a sign that something is not quite right with your roses. With a bit of sleuthing, you can find the culprit and determine the best solution to get them back on track.
Remember that roses love sun, deep infrequent watering, rich organic soil, and adequate airflow. Provide these ingredients along with a balanced approach to pest and weed management, and you’ll find that your roses grow healthy and strong!
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