NOTE: In this article, Star cactus and Astrophytum spp. may be used interchangeably; in fact, Astrophytum spp. is the botanical name for Star cactus.
There are six North American cacti species found in Mexico and the southwest portion of the United States. Three of the six species are referred to as “star cactus” because of their ribbed structure that has a star-like shape.
The star cactus has a body covered with aureoles that are black or golden. White flocking is an adaptation designed to protect the plant’s tissues from sunlight, as well as yellow, orange, and red flowers that bloom from the plant’s center.
Why does my Astrophytum spp. roots have rot?
Root rot on your Star cactus (Astrophytum spp.) can be fatal if not treated with care. For this reason, we strongly recommend that you follow our guide to keep your plant alive if the symptoms occur: Root soft and blackened.
Why does my Star cactus have gray mold spots?
A particular fungus known as gray mold spots spreads quickly and frequently damages flowers. This fungus is probably to blame if you see any brown (or gray) spots. If you disregard these warning signs, your plant could die.
The answer is obvious once you recognize the cause of the problem. Most frequently, it results from the Astrophytum spp. being overwatered. We strongly advise you to remove the damaged plant parts, cut off the diseased roots and leaves, and then repot your plant in a new container with sterile potting soil.
Why does my Star cactus have leaf spots?
This type of disease is one of the most frustrating for Star cactus owners, we give you all the leads to spot and save your plants that present symptoms such as leaves that suddenly change color, or wilt/droop.
Why are my Star cactus leaves turning yellow?
This is probably the most common problem in the gardening world, yellowing leaves. There are 2 main reasons for this phenomenon, overwatering, or a lack of nutrients.
When it’s overwatering, simply reduce your watering frequency, and if you think it’s a nutrient deficiency, here’s how to check it:
Here are some signs of yellowing caused by the many deficiencies on the Astrophytum spp. in question:
- Yellow patches between leaf veins on elder leaves are the first sign of magnesium shortage. Veins continue to be green while the leaf’s core turns yellow. The leaf’s edges yellow last.
- Another indicator of iron deficiency is yellowing between leaf veins, but young leaves on plant tops and branch tips are first affected.
- Sulfur deficiency starts with the newest leaves, turning them yellow throughout.
- Insufficient potassium causes the leaf edges to turn brilliant yellow while the interior of the leaf stays green. Older leaves show the symptoms initially, and the leaf edges quickly darken.
- Nitrogen deficiency shows up as a general yellowing. Older, inner leaves turn yellow first. As it progresses, yellowing moves outward, eventually reaching young leaves, too.
You only need to respond to the signs mentioned above. A gardening store expert will be able to provide you advice on how to purchase a specific soil to treat a potassium or nitrogen deficiency. Additionally, you can reduce how often you water your plants.
Is my Star cactus sunburned?
It is quite easy to find out if your Star cactus (Astrophytum spp.) has been burned by the sun. Just like on us, your plant will change color in this case, it will start to turn yellow or white.
The leaves of your Star cactus can also change color in case it gets too much water or not enough light, as we saw above.
The bottom of the yellow leaves with a shaded area closer to the base can be examined to determine if they have been sunburned. If this part remains greener, the yellow leaf is most likely sunburned and not something else.
Why are my Star cactus leaves turning brown?
The classic sign that a plant has been overexposed to direct sunlight and sunburned is the development of browning leaves. Rest assured that while this may probably save your plant from dying, it will adversely affect its growth.
Should I leave my Astrophytum spp. in direct sunlight?
No! If your Astrophytum spp. (or Star cactus) has the symptoms described above, don’t leave it in direct sunlight, that’s the reason why your Star cactus is in such a state!
The remedy, as said in the paragraph above, is simple: just move your plant’s Star cactus out of direct sunlight. Your plant should swiftly re-grow with this strategy and appropriate watering.
Why are my Astrophytum spp. leaves drooping or wilting ?
This typically occurs when your Astrophytum spp. gets dehydrated. Large plants are more at risk since they naturally require more water than smaller plants.
Whether your Astrophytum spp. plant’s pot appears light, the soil and roots are likely fairly dry and need water, so you can readily tell if it needs to be hydrated.
If the soil in the container is completely dry, you must first moisten it to guarantee that your plant’s roots absorb the benefits of the water. One common mistake is to drown the Star cactus right away after a dry time because you think it needs a lot of water.
This is true, but the easiest way to end it is to give too much water at once. Instead, you should water the soil properly, returning to a peaceful watering rhythm.
Caring Tips for Astrophytum spp.
Water is essential to the survival of your plant, however, it is important to balance the rate of watering. As we explained above, overwatering could have fatal consequences for your Astrophytum spp..
You can tell if your plant needs water by touching the soil; if it still feels damp, it’s usually preferable to wait a few more days.
Always keep temperatures stable
Maintaining a consistent temperature for your Astrophytum spp. is also a good idea, especially if it is kept indoors. At GreenShack, we typically advise reserving a temperature between 65 and 85 degrees F. Of course, avoid positioning your Astrophytum spp. close to air conditioners, radiators, or other sources of hot or cold air.
Keep your Star cactus Dust-Free
This one concerns indoor plants, just like on your furniture, dust is also deposited on the leaves of your indoor plants, the problem is that it can prevent them from receiving the necessary light, this would slow down (or even stop) the photosynthesis process, and eventually, they would lose their colors.
This would also make the pests happy, a real descent into hell for your Star cactus.
Take a microfiber cloth and gently massage the plant’s leaves to get rid of the dust. Use a damp cloth to make dust removal easier, but avoid using corrosive materials like rubbing alcohol!
Keep drainage in mind
If you have a tendency to overwater, you need to keep an eye on your drainage, we advise you to opt for a pot with drainage holes if it is not already the case and a saucer.
You can add volcanic rocks (or any other pebbles with holes) to the bottom of your pot in the interim if your pots don’t already have holes in them. This will help to form a channel so that the water doesn’t pool there for too long (preventing the rot of the roots!).