7 Reasons Camellia Leaves Turn Yellow and How to Fix it
Are the leaves on your camellia turning yellow this season? Unfortunately, there are a number of different reasons this can happen. In this article, gardening expert Melissa Strauss walks through why the leaves on your camellia may be turning yellow, and how to fix it!
Camellias are a stunning fixture in many of the most noteworthy southern gardens. They boast an impressive variety of different species and hybrids, with a wide range of colors and petal formations. From white, yellow to more commonly seen pink and red varieties, it’s no wonder these winter blooming beauties are so popular.
In addition to their grand and gorgeous blooms, one of the most striking qualities of the camellia family is their glossy, modeled, dark green leaves. These popular perennial shrubs flower prolifically from late fall through early spring if planted and cared for in the proper way.
But it is their dense evergreen leaves that create a beautiful hedge or backdrop year round for gardens in zones 7-10. Naturally, when camellia owners see these gorgeous green leaves start to fade and yellow, it is a concern that must be dealt with, and quickly.
Yellowing camellia leaves are usually caused by nutrient deficiency. This can be the result of a surprising number of different factors. Let’s dive into some of the most common reasons why you might be seeing the leaves on your camellias turning yellow and see what we can do to restore that beautiful ,green gloss.
The most common cause of nutrient deficiency in camellias is soil pH. You may notice that your camellia’s new growth is coming in yellow, but the older leaves retain their usual dark green. This indicates an issue with the acidity of your soil.
That may sound like a complex problem. But there are actually simple solutions that can remedy the issue in just about any circumstance.
Camellias prefer slightly acidic soil (pH 5.5-6.5 is ideal). When the soil is too alkaline, they will have difficulty absorbing adequate levels of certain nutrients. More acidic soil helps to break down nutrients like iron and manganese. In turn, these minerals become more available for the plant to absorb.
When the soil is too alkaline, the plant will struggle to absorb the nutrients it needs. The newer growth will let you know this by its lack of the signature dark green color of its leaves.
How to Fix It
There are several ways to rectify a pH issue in your soil. The method you choose should be largely dependent on the surrounding plants. If your camellia is located near other plants that thrive in the alkaline soil, you can use an acidic fertilizer to concentrate the effect on that specific plant. This will help prevent concurrent harm to the surrounding plants.
If your camellia is planted adjacent to other acid loving plants, the solution is to amend the soil with one of the following methods to lower the overall pH.
Sulfur is effective if added to soil before planting or relocating your camellias, but it takes some time to acidify the soil, so adding it after the fact is not the most effective method.
Iron Sulfate can be used around existing plants; use moderately as overuse can cause more harm than good.
Sphagnum Peat Moss
Sphagnum Peat Moss is a safe and long-lasting way to acidify your soil. 4-6 inches on top of existing soil should add adequate acidity for up to 2 years.
Ammonium Sulfate is a safer alternative to aluminum sulfate but use with care as it can damage plants if overused.
Other Acidic Organic Material
Other acidic organic material can be used in the same way as sphagnum moss. (pine straw or compost work well)
The Location has Poor Drainage
Camellias like to be watered regularly, but their roots don’t like to stay wet. If you notice entire leaves turning yellow and your plant beginning to wilt as a whole, there is a chance you may have root rot.
If the issue is a simple lack of proper drainage, and no other infection has taken up residence, relocating the plant to a well drained location may help your plant to recover.
In addition to root rot caused by poor drainage, there is a form of root rot caused by a fungus known as phytophthora cinamomi. I will address this below in the section regarding fungus and disease.
This is more serious than root rot caused by poor drainage. A plant can recover from the latter, while phytophthora causes whole plant death. To determine which type of root rot you have, look at the roots themselves. With poor drainage root rot, the roots will be white. Phytophthora causes the root system to turn a reddish brown color.
How to Fix it
Mixing some sand or sphagnum moss into the soil may help alleviate the issue if it not severe, but is not a great long-term solution. In this case, location is everything. If you plant a camellia in the right place, it will be a low-maintenance plant.
If you plant a camellia in a marshy spot, you will run into this issue throughout the lifespan of the plant (which will be significantly shortened). Replanting in a spot that has proper drainage will do a world of good.
Not Enough Water
If your camellia leaves are wilting, turning from yellow to brown, and generally looking a bit crunchy, they probably need water. Camellias like well-drained soil, but they do need to be watered regularly. For mature plants, regular amounts of rain may be sufficient.
Another culprit of underwatered camellias is soil that is made up from a majority of clay (North Florida/Southern Georgia, I’m looking at you). Water may have a difficult time absorbing into this type of soil to adequately reach the roots. Lack of water means a lack of nutrient absorption.
How to Fix It
If you’re experiencing a dry spell to the tune of 2 weeks or more, make sure you give your camellias some water to get them through the dry weather. If your soil is hard clay or made up of a majority of sand, you may need to enrich the soil.
Replanting and mixing in topsoil is one solution, but it’s a labor-intensive one. A simpler method is to pile on a thick layer or wood chips, and this will enrich the soil as it breaks down. Pine bark mulch is perfect as it adds that acidity that camellias crave.
Lost Nutrients Due to Pests
There are a handful of pests that can affect camellias, among them are scale, spider mites and aphids. These may leave your camellia leaves looking more moldy than yellow, but they are worth discussing because they are fairly common, and also fairly easy to treat.
Scale can be identified by the white, moldy appearance they leave in their wake, this is easy to identify and to treat, and treatment is generally very effective. Scale will also inhibit new growth. Powdery white under leaves and yellow mottling along with a lack of new growth generally indicates a scale infestation.
Spider mites will be apparent by a grey/bronze marking on the top of the leaves. To test for spider mites, hold a sheet of paper beneath an affected leaf and give it a few taps, the mites will be visible to the human eye, and will drop from the leaf onto the paper.
Aphids are a common garden nuisance that affect a wide variety of plants. They love a tender leaf to munch on, so this issue can be detected mainly on new growth. Aphids leave a black moldy substance on the leaves they visit. This mold has to be wiped from the leaves to prevent further damage.
How to Fix It
My favorite insecticide, as a beekeeper, is neem oil. Neem oil can be sprayed on the affected plant in the evening, when pollinators are at rest, and when it dries it is no longer dangerous to insects, so by the morning, it should be safe for pollinators to once again visit your plants.
Neem oil is safe for people and animals and has a wide variety of useful applications. There are other approved insecticidal soaps and oils that can rid you of these pests as well.
The best way to prevent insect infestation is proper pruning. By thinning out the inner branches of your camellia yearly, you allow sunlight and proper airflow to the interior of the plant. This goes a long way in preventing an infestation in the first place.
Disease or Fungus
The predominant funguses that present with yellowing leaves are phytophthora cinamomi root rot, and yellow mottle leaf virus. The more serious problem fungus known to cause yellowing leaves and root rot is phytophthora cinamomi.
Confirmation of phytophthora infection can be observed clearly at the root, which will turn a reddish-brown color, rather than the normal white color of a healthy plant.
Mottle leaf virus shows up by way of irregular yellow splotches on leaves. It is generally spread by unhygienic propagation, and there is no remedy. However, it causes no lasting damage to the plant save for the discoloration, which can actually be quite pretty.
For this reason, some growers propagate plants intentionally to have this virus sheerly for the signature mottled leaves. Talk about finding the silver lining!
How to Fix It
Sadly, there is no cure for phytophthora infection, and you are likely to lose this plant. The infected plant should be removed to a landfill, away from other plants so that the infection does not spread.
There are preventative measures that can be taken to prevent this from happening to other plants though. C. Sasanquas is more resistant to the fungus than c. Japonica.
Planting camellias in an area with adequate drainage is also a helpful preventative. Root rot caused by poor drainage makes the root system more vulnerable to the phytophthora fungus.
Too Much Fertilizer
Camellias do not require much fertilizing. If they are happy with the amount of water and the type of soil they are planted in, they should only need a light fertilizing at most, 3 times per year. Too much nitrogen can burn the leaves and cause yellowing and brown spots.
How to Fix It
Young plants need a bit more nitrogen than mature plants, a 10-10-10 formula should be just about right. A mature plant will need about half the nitrogen to thrive.
Once your camellia reaches that 4-year maturation mark, reduce to a 4-8-8 formula no more than 3 times per year and you should be able to avoid this issue. If you’ve already encountered this one, hold back on fertilizing for a few months to see if the new growth appears healthy.
Lack of Nutrients in the Soil
Although camellias only need occasional fertilizing, they do benefit from some added nutrients. If you haven’t fed your camellias in a while, a light fertilizing with a 4-8-8 formula may do a world of good.
As I mentioned earlier, the wrong pH level in your soil can contribute to this problem. Certain important nutrients are not broken down adequately in alkaline soil. A proper balance of acidity and light fertilizing will keep your camellia leaves dark green and glossy.
Yellowing camellia leaves can be caused by a wide variety of issues. The underlying factor in nearly all of them is the lack of absorption or availability of certain nutrients that the plant needs to survive. If you see these symptoms showing up in your camellias, take a deep breath and a good look at the plant’s habitat. Try a holistic approach. As, with many of the more serious issues, there are additional symptoms that will point you in the right direction.
Remember that the most important factor in maintaining the health of your camellia is where it is planted, and how it is pruned. Keep internal branches pruned to allow sunlight and air circulation and you will prevent a host of plant damaging factors. Soil acidity and drainage will solve most of the others.