10 Reasons for Yellow Leaves on Roses: Expert Treatments

Sharing is caring!

Last Updated on April 19, 2023 by Tony Manhart

What are 10 reasons for yellow leaves on roses that are common and easy to treat? There is a saying that we learn from mistakes. Rose gardening is one of those places where it is really easy to make a lot of mistakes – I love plants, and giving roses too much love kills them. Much like a human relationship, if you shower it with love, it will not appreciate it and die. Join me as we investigate the thorny issues around why rose leaves turn yellow.

A rose is one of the more rewarding flowers to grow. These are quite addictive to grow, and over the years I have grown various types, from the wildish banksia type roses to the exotic hybrids. Learning how to grow any plant involves learning what not to do – and I have done quite a few of these things.

There is an effect called the Dunning-Kruger effect – which, when it comes to growing roses, exerts an effect that results in the rose leaves turning yellow, or the plants even perishing. In other words, when you think you know a lot about roses, but do not, you kill them. This appears to be quite evident in many of the blogs that I have read about reasons for rose leaves turning yellow.

You are less likely to find yellow leaves on a neglected rose than on an over-attended rose. There is a lesson in there. More often than not, the reasons leaves on a rose turn yellow are probably because you gave it too much attention. This article will show you how to care for your rose when it needs help, and how to ignore it and allow it to thrive when it just needs to figure its own path out. Let it run free and if it comes back and gives you a beautiful bloom it was meant to be your rose.

What Are Yellow Leaves on Roses?

When we start looking at the top 10 reasons for yellow leaves on roses, it is probably useful to first define what a “yellow leaf” is. When leaves turn yellow the chloroplasts are green and contain chlorophyll which drives photosynthesis.

Chloroplasts are plastids – a type of ancient bacterium that lives in cells, and these are partially under the control of the cell – they can signal to them, that they need to turn from for instance a chloroplast to a chromoplast. When they do this, the cells dismantle the chlorophyll pigment and many of the metal ions that are important to these pigments – iron, copper, manganese, and magnesium specifically – can be scavenged and moved elsewhere in the plants. When this happens, the chloroplast stops being a chloroplast and can become another type of plastic – such as a chromoplast – that is yellow. The leaf will turn from green to yellow. This is a nice explainer of plastids and how they work and how the cell talks to them.

A leaf has a natural lifespan – this means that a plant will use it as long as the leaf works, and as it gets old, it will cannibalize the leaf for nutrients to put into new leaves. Old leaves often become yellow and fall off a plant once the useful stuff has been removed from them. In deciduous plants, leaves will be cannibalized in the fall for useful components, and then the leaves fall as compost on the soil to drive the next season’s nutrient release from the soil which benefits the trees. This is why mulch is important.

pH

Before we have a look at my 10 reasons for yellow leaves on roses, I would like to draw your attention to pH. pH is a measure of the amount of acid or alkaline material in your soil with a pH of 7 being neutral. I believe in constructing soil for roses – do not use whatever is lying around – sand, compost, pearlite, and manure mixed and you have a good basic rose soil.

Good soil mixed as above should have a pH in the 6-7 range, which is a range in which roses are broadly happy. If you go below 6 or above 7, you will struggle to keep a rose alive or healthy. It is just an uphill battle.

I have read a lot of blogs where people talk about adjusting soil pH for roses etc and in my opinion, this is largely bad advice. Get your soil tested – if it is outside this range, don’t even waste your time with your soil – mix some premixed soil and make it correct from the start. You will save yourself a lot of pain and dead rose bushes.

10 Reasons for Yellow Leaves on Roses

The majority of lists on rose leaves turning yellow always seem to suggest a Nitrogen deficiency. In my experience, if you have even vaguely good soil and a small layer of mulch you will not pick up a Nitrogen deficiency. Hence I will not include this as one of the reasons as it really is such a simple one to diagnose. Nitrogen-deficient roses have leaves that are pale all over – a small dose of Nitrogen (pee on the rose a few times) or a little bit of organic fertilizer and the Nitrogen deficiency is fixed. This one is not worth putting in a list.

1) Roses are deciduous

A rose is classified as a deciduous bush. Deciduous plants lose their leaves as temperatures drop and days get shorter to survive cold winters. As temperatures drop in fall, the rose bush will relocate essential nutrients from the leaves to the roots in preparation for winter dormancy.

The leaves go yellow and drop at this point. If you are in North America and your rose bush gets yellow leaves in October, it is going dormant. You can stop watering it, and if necessary, wrap it up for winter (ask around at local nurseries what works in your area. In milder climates roses need no help – in more severe climates they need to be wrapped up for winter).

2) Your rose bushes are dry

Roses are surprisingly drought tolerant – they actually seem to enjoy having some dry time. But too much will cause them to go dormant, or die. If they get dry, they will pull nutrients out of their leaves quickly and store this in the plant. They can then go dormant and hopefully survive until wetter conditions prevail. If it is warm, the roses are going yellow, and the soil is dry, giving your roses some water really helps.

Mulch them as well. Pine needles are my favorite mulch for roses, and, unless you live in a really dry area, you will find that one or two waterings a month, plus natural rain will be more than enough for your roses. They like the soil to be slightly moist. Roses do not like overwatering.

3) Your rose bushes are TOO wet

This is the most common problem I have encountered with roses. If they get overwatered they become truly miserable plants. Roses ideally need loose, well-drained, compost-rich soil. If a soil such as this is overwatered, it becomes anaerobic – there is not enough, or no oxygen in the soil. When this happens, the roots of the plant will begin to die, and rot and your plant cannot absorb nutrients. If the situation is slightly less harmful – wet, but not waterlogged soil – you can still find that the rose will struggle to absorb certain nutrients.

I try to move roses from bad soil to good soil. You can dig up a rose in winter when it is dormant and move it into good well drained sandy soil with lots of compost and pearlite. With time the earthworms will mix the pearlite into the soil and it will eventually improve. Pearlite does wonders for soils that have poor aeration and waterlogging issues. It is single-handedly one of the best amendments you can add to the soil.

If you cannot move the bush, use something like this (Walensee Lawn Coring Aerator) to introduce ventilation holes in the soil and fill these holes with pearlite.

When watering rose bushes follow a cycle where you water them, and then watch the bushes – I water them again at the point that they start to droop just a little bit. If you follow this cycle they seem to thrive because the watering helps them top up their water and nutrient stores, and as they pull the water out of the soil it pulls oxygen into the soil, and then when the soil is quite dry and aerated, you add water again and repeat the cycle.

4) Magnesium deficiency

When roses become magnesium deficient, they tend to move magnesium from older leaves to newer leaves. You will see the older leaves get yellow around the edges but stay green around the middle vein of the leaf. The leaves get progressively yellower until they drop.

I often have this problem with my roses and my citrus plants and I use the following solution. Once a month I treat myself to Epsom salt. Magnesium sulfate is the main ingredient in these sorts of bath salts, and it helps to draw impurities out of your skin. Generally, a long soak in a bath with a cup and a half of Epsom salts makes you feel great! I then take this bath water out and put it in buckets and give it to my roses and citrus trees. They are very grateful!

Alternatively, you can actually buy Epsom salts for your plants and mix a cup of Epsom salts in a gallon of water and sprinkle that on the soil around the base of your rose bush. Repeat this twice a year.

Trust me the bathing is a lot more fun, and you get double the benefit per cup of Epsom salts.

5) Iron deficiency

Iron is, like Magnesium, essential for producing chlorophyll. Without Iron, your leaves can’t be green! What I have seen is that an Iron deficiency typically looks almost the same as a Magnesium deficiency, except that it is the young leaves that look yellow not the old leaves! The soils in my garden are quite iron deficient and I take all my old iron cans (what we call tin cans) and I burn them to remove the protective layer on them. Following this, I bury them below the mulch that I put everywhere. The soil here seems to break the cans down into rusty powder very quickly and this has stopped all iron deficiency in my garden.

You can also add a chelated iron product. If we look at the nature of Iron, when it is in its ionic form (as in soluble) it tends to be one of those ions that can stick to a lot of things and stop being soluble. This means that if you add something like Iron sulfate to your soil, it will often just not be available to your plants. I like chelated Iron because the chelating agent makes the Iron more soluble – in many cases, you can even spray it right onto the leaves and the plant will absorb it right where it is needed. This is important to do in bad cases, as your plant can be so weak it cannot absorb much from its roots anymore.

6) Copper, zinc, and boron deficiency

If the previous two nutrients do not seem to be diagnosable, then there is a possibility that you may have another nutrient deficiency. These other ones are really difficult to diagnose and often the conditions that cause one cause the other so that you could have a mix of a few or all of them, and then you get weird and wonderful deformed leaves and yellow blotches and all sorts of things that require a lot of skill to understand.

Fear not – I just use a multi-micro nutrient mix and this normally solves the problem. In fact, I keep a spray bottle of this stuff mixed all the time and just give plants a little spritz of it every now and then whenever I see slightly deformed or spotty leaves.

Do Roses Like Coffee Grounds? A Secret Hack!

7) Shaded leaves

A leaf getting too much shade will not produce much sugar via photosynthesis. If it keeps underperforming in this way, the rose bush will get rid of it. So it will go yellow and eventually fall off. This is nothing to worry about and let the process run its course.

8) Fungus issues

If your rose plant is a bit unhealthy it will become susceptible to fungal infection – with the black -spot fungus being one of the more common fungal problems here. This is quite an easy-to-diagnose problem as the leaves get round black spots on them. With time the leaf turns yellow and the plant will drop its leaves. Many people suggest raking the leaves up and disposing of them. I never bother, but I do feed my plants to make them healthy and the fungus tends to become less problematic. If a rose gets so sick it dies from this, I just never plant that cultivar again. Some cultivars are more resistant to black-spot than others.

9) Rose leaves turning yellow – Mites

Spider mites are an absolute nuisance, and in hot dry weather, these critters move around your garden on little threads. They drift in the wind. I always plant roses in dry, sunny areas, and the result is that these creatures find the roses and will multiply under the leaves causing yellow leaves on roses.

The mites are easy to spot – they weave little webs under the leaves. I use neem oil to control them. This pack, mentioned above, includes fungal and spider mite control in terms of the neem oil. You often find that where there are mites, there are fungi, so treat for both.

After treatment, you can keep mite numbers down by hosing your leaves. They hate water.

10) Dog or human pee/overfertilizing

If you add too much fertilizer (Nitrogen containing) the plants can turn very yellow due to a Nitrogen burn. Interestingly enough, roses that are strategically placed where dogs and or humans will be tempted to pee on them can become overfertilized too. Teenage boys drink a lot of water and pee on many things in gardens. Drunk adults as well. This is an exceptionally common cause of “yellow leaves on roses”. Roses enjoy being peed on once a week or so – anything more and they will get yellow leaves.

If you overfertilized the rose with fertilizer, you can try and rinse the soil by watering the plant well. This may wash the fertilizer away. If it has been a pee issue, installing some sort of barrier that keeps the dog/human problem at bay can help. A mulch will help to absorb and process pee quickly. When I have a problem with dogs anointing a plant excessively I normally put a rock mulch around the plant – larger rocks tend to deflect the problem and take it away from direct root contact.

Should Yellow Leaves be Removed from Roses?

This will depend on the cause. I tend to not remove them. If the problem is fungal, most people suggest removing the leaves and disposing of them. This will reduce the fungal spore load in the area, and reduce the risk of reinfection.

In general,yellow leaves on roses will remove themselves. I would not bother. Let the plant scavenge the nutrients it can and then drop the leaf when it is ready.

How to Fix Yellow Leaves on Roses

Once you have identified which of the reasons above are the cause of your rose leaves turning yellow, you can implement the correct procedures to fix your roses. This may involve watering less, or more, introducing aeration, ensuring the trace minerals are balanced, and controlling pests. Each of the above paragraphs details a problem and a solution. Within no time you should be able to fix your roses and get them back on their path to beautiful flowers.

Summing Up Reasons for Yellow Leaves on Roses

Rose leaves turn yellow for several very simple reasons, one of the most common being pH of the soil is too high causing nutrient deficiencies. If the pH is right, you could have watering issues – either drought stress/underwatering or overwatering causing reduced plant health. It could be something simple like shading causing yellow leaves as a result of not having enough sunlight for the plants.

Nitrogen, Magnesium, and Iron deficiencies in soil are easy to remedy. If you go a bit far on the Nitrogen you can cause overfertilization issues. Sometimes a  lack of soil nutrients, such as Boron, Copper, and other micronutrients can be a problem. A lack of light, or too much light and overheating can cause leaves to yellow. Diseases and pests can also cause yellow leaves. Insufficient sunlight and low temperatures trigger winter dormancy and cause yellow leaves on roses.

Sharing is caring!