Why is My Cactus Turning Yellow? (8 Things to Check)

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If your cactus plant’s leaves or stem turn yellow, this is a visual sign to let you know it needs some help. Sometimes, it is due to a lack of water, which can make succulents turn yellow or brown. Keep reading to see how to fix it.

Main Reasons for Cactus Turning Yellow

1. Lack of water

If your cactus plant looks yellow (and shriveled) in summer, then first of all try giving the plant a really good soaking. Make sure you wet the root ball and allow the excess to drain away. Does this help? Check it again after one day to see if the plant looks a bit happier.

2. The quality of your water

Tap water contains fluoride and other chemicals which your cactus may not enjoy. Over time, white salts may show in your soil.

3. Check for white, powdery leftover salts on the topsoil

If they are present, try a really good soaking, and then drain the plant.

4. Another trick is to use distilled water, i.e. leftover boiled from a kettle

This usually makes a difference. If all else fails, change the soil regularly.

Overwatering combined with bad drainage can also make your cactus plant look less than its best. This is actually the reason most cactus plants have problems.

Only water when the soil is really dry; check the soil. Then provide them a good watering, like the plant would get in the desert during a storm.

Check the drainage holes are not blocked, for example, by a stone. These plants enjoy sandy soil which allows water to drain away quickly.

5. Location – is your cactus plant getting enough sunlight?

Household cacti do not like getting too much sun through glass, because this may cause leaf burn. However, remember they are desert plants that are used to lots of bright sunshine for long, desert days. So a sunny location is ideal, but not so much that causes leaf burn.

6. Temperature

Cacti are succulent perennial plants, which enjoy the sun but are used to lower temperatures at night. Too much sun can cause yellow leaves. Their leaves will turn black and cause the death of the plant if they are placed in frosty conditions so keep them out of drafts.

7. Soil and nutrients

If your cactus plant is in a pot that is too small, their leaves may complain by turning yellow. A re-pot and a soil change might make a difference! However, be cautious with adding soil that is too rich. Cactus plants like low nitrogen soil – see more in FAQs below.

8. Pests

They are but some household cacti get aphids, mealy bugs, and occasionally red spider mites. Use a damp cloth and dish soap diluted in water to wipe the leaves down carefully occassionally. This should remove them. Red spider mites hate damp so this will discourage them from coming back too!

Why is my cactus turning yellow and mushy?

The answer to this is usually overzealous watering, and this plant may have root rot as a result. Is the color change at the tip, on the stem, or the root? Read on to solve these problems.

Why is my cactus turning brown at the base & at the top?

Sometimes you will notice a part of your cactus turning yellowy-brown. This can be either at the base, at the top of the plant, or sometimes even the stem. There are a few possible causes of cactus plants turning brown it is really important that you take prompt action!

First, the location of the brown part is important.

If it is on the stem:

Prune the brown, rotting part of the plant and destroy it. Clean the secateurs or knives at each cut. This will stop spreading the disease to other healthy parts of the plant.

Next, examine the piece of stem you have cut. Is the inside of the stem also brown? Brown on the stem can mean that the rot is spreading inside the plant too.

It is important to cut the plant right back to where you can see clean, green growth. This may be a hard prune, particularly as you love your plant but it really is essential to get rid of any browning flesh on the plant. This may be caused by root rot or fungus disease.

After the pruning, make sure you do not overwater your cactus. This is usually what causes root rot. Thus, water only when the pot feels dry. Then, give it a good soaking, allowing the excess to drip onto a saucer, and remove this after 30 minutes.

If the brown part is on the tip of the plant, prune as above and see how far the rot is spreading. Do not forget to clean the secateurs or knives after each cut!

If everything looks green below the cut, clean the knife and step away! However, if a cactus begins to rot from the tip of the stem it can be hard to stop it. Keep a close eye on your cactus in case of future attacks.

If the root is brown, you have a lot of work to do!

The browning or mushiness of a root indicates root rot. If you do not dry your plant out, then it may die. Take it out of the pot carefully and observe the roots. Try to clean off any really darkened areas. Prune these and discard them.

Set the plant on newspaper or cardboard and let it dry out so that the roots appear dry. Healthy roots are creamy-white and do not smell.

Now pick a sandy soil that has good drainage and does not feed a cactus with too much nitrogen. This can cause odd leaf growth. So re-pot in dry, sandy soil and water much less than before.

Make sure the plant is getting enough sunlight but not so much that the leaves burn.

Keep a careful eye on this plant because root rot is often deadly. If some green growth occurs after the pruning, breathe a sigh of relief and treat your cactus well from now on.

cactus

Different types of cactus: Typical problems and how to fix them

There are nearly 2000 species of cactus worldwide growing from Asia to Africa, Europe, America from Texas and Arizona to Mexico, Central America, and South America.

Most cacti enjoy sandy, well-draining, desert-type soil with strong sunlight and arid conditions. As house plants, you need to recreate their native conditions as closely as possible.

Make sure you read any plant label carefully. Now, read on for common problems and how you can help your particular cactus back to health.

Why is my Barrel cactus turning yellow?

The Barrel cactus is very sensitive to strong sunlight so when its leaves turn yellow, this may indicate leaf burn. Obviously, like humans who get sunburned, the first thing to do is to take your cactus out of direct sunlight for a while.

Put it in a location where the sunlight is indirect for a while and see if the leaves begin to take on a green tinge. If so, you have solved the problem.

Another possibility is over-watering. Thus, make sure you let the plant dry out well between waterings and check the soil before you add any more.

Why is my Pencil cactus turning yellow?

The Pencil cactus tends to drop older leaves, which have turned yellow. As the plant grows, like any other plant, some early leaves die off and this is exactly the same for your Pencil cactus.

It is part of the growing process; thus just remove the leaves. But if you are still worried check the list above for what can go wrong with cacti such as watering, soil, fertilizer, and sunshine.

Why is my Totem Pole cactus turning yellow?

The Totem Pole cactus can turn yellowish when it feels very dry.

The answer is usually to give it a generous drink of water! If the leaves don’t look their best, for example, if the texture is wrinkled, then water is definitely the answer.

Like most cacti, your Totem Pole plant needs to be watered when its soil feels dry to the touch, and then they enjoy a good soaking so that their whole root ball is moist.

Why is my Moon cactus turning yellow?

Moon cactus is actually two cacti grafted together, with the top part being the flowering one. It is often called the Star cactus due to its colorful star-shaped flowers.

When the plant turns yellow it is usually caused by dryness and not enough watering. Make sure your plant is in suitable soil so that the water can drain away easily. Only water it when the topsoil is dry; then soak it thoroughly and drain away excess runoff from any saucer it sits in. This will avoid root rot.

It will not hurt to fertilize your Moon cactus, just before it flowers. But make sure the feed is low nitrogen though because cacti prefer this.

Why is my Euphorbia cactus turning yellow?

Probably this cactus needs more light. Try moving it into a sunnier location and see if they change to a greener tone. Next, check the watering. Too much water causes Euphorbia to change leaf color to a more yellowish shade.

If this does not work, then check the plant is not in a draft that makes it feel cooler than it prefers. Lastly, if the leaves are still yellow, check for root rot, hoping this is not the case!

Check “Why is my cactus turning brown?“ (above) for how to fix this.

FAQs

How can I save my yellowing cactus?

In general, a yellow cactus often indicates that there may be too much water in the pot, but ironically, it can also indicate too little. Cacti feel soft when dehydrated. Other factors you can check include:

  • Right light
  • Good soil
  • Proper fertilizers
  • Temperature

So first, as a general rule for all cacti, do not water them too much. Allow the soil to completely dry out before you start adding more. This will help to avoid root rot too.

If the plant is yellow, wrinkled, and the roots smell, root rot may be the cause of its yellow leaves. In this case, go back to the section about the browning of cactus plants and follow the instructions.

It may be a feature of your particular type of cacti that the leaves change according to the light it receives these are the four things you need to worry about to ensure that your cactus thrives.

Can I grow cacti outdoors successfully?

Some cactus plants are better at surviving outdoors than others. If you leave a succulent outdoors and there is frost, the result is usually black leaves and the most likely cause is that the cactus plant will die. One way to avoid this is to provide some protection, by covering the plant with a polythene or cloth layer in colder periods.

I do not recommend growing cactus outside unless you are in a tropical zone. Some may like the extra sun in a sheltered area in summer. However, with the cool fall winds, move it indoors.

Do I need to fertilize my cactus plant?

Cactus survive well in the wild, with savage differences between hot daytime temperature and nighttime lows.  An indoor cactus can be cared for by providing all the basics like water, light, nutrients, and temperature but in spring when the growing period starts, it is a good idea to fertilize your plant.

Do not use a fertilizer that adds high nitrogen. Cactus plants prefer a low nitrogen mixture and if the nutrients are excessive, it will not help your plant and may cause leaves to become excessively fleshy.

Do not fertilize in the winter. Most plants do not need it outside of their growing season because excessive nutrition may just sit in the soil and eventually cause root rot.

Do not fertilize if you have just re-potted your plant. Cactus does not like excessive nitrogen either. But allow a new re-potted plant to settle for a few weeks before you fertilize it.

If you notice your cactus plant is flowering, then you should definitely feed it! You can purchase a specialist cactus feed; the most important aspect is that these usually have a lower nitrogen content than normal household plant feeds, which the cactus enjoys.

However, as long as the nitrogen content is no higher than 10, you can use household plant fertilizers using the 10-10-10 ratio, which gives 10% of nitrogen, phosphorus, and potassium. Healthy plants need all of these to thrive.

How can I help my cactus plant to flower?

Several types of cacti offer gorgeous flowers in the wild, usually after a rainy period or at times of optimum health and good fertilization.

It is important to read the label that comes with your plant to learn when it usually flowers. For example, the Christmas cactus usually flowers in December, not in the summer, so this plant is effectively dormant in summer and needs to be fertilized in winter to encourage flowering.

For other types such as the Moon cactus, remember that they are actually two different types of cactus grafted together. The flowers occur on the top plant, so check the flowering season when you buy and fertilize to suit the expected time of flowering.

Mike Smith

I love Gardening and this is my site. Here you will find some really useful plant-related tips and tricks.