It is a common belief that all cacti need as much light as possible. As a desert plant, it needs to be in the sun or bright indirect light. However, too much sunlight means higher temperatures which can be actually damaging to cacti.
Whether you keep your cacti in pots or ground, on really hot and sunny day water will evaporate quickly leaving your plants dry. It can also result in sunburns. It can be a big problem if you are growing cacti in a greenhouse.
However, you can easily avoid these problems! How? You probably guessed it – use a shade cloth!
So, in this blog post, you will find out whether cacti need shading at all and what cacti species can grow in partial shade. Also, you will learn what a shade cloth is, how it works and what percentage shade cloth do you need to use in your location.
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How much light does a cactus need?
Cacti need between 10 – 14 hours of bright indirect light a day. Cacti in a south-facing position will get a good amount of light. Don’t put your plants in direct sunlight as too much heat from the sun can burn cacti. Indoor plants need at least 4 hours of direct sunlight a day.
You need to be extra careful during the summer months. Depending on your location temperatures can go up way above 90oF which is damaging for some species of cacti. Keep in mind that the majority of cacti species thrive in temperatures between 45oF -85oF (7oC-29oC).
Can cacti grow in shade?
Most succulents, including cacti, don’t grow well in minimal sun or in full or partial shade. They become thin and sickly. However, there are some cacti species that grow in low light.
What cacti can grow in shade?
So, if only three species thrive in low light, you might be wondering why do you need a shade cloth for your cacti collection?
Let me explain why a shade cloth is so important.
Why do you need a shade cloth for cacti?
If you keep your cacti collection outside or in a greenhouse for summer, the temperature can go over 100oF and damage your plants. It can quickly cause sunburn and your cacti will turn yellow or even brown. Adding shade cloth protects your cacti from direct sunlight and cools them down.
If you have no idea what a shade cloth is, read this article where I am explaining what is a shade cloth made of and how it cools the greenhouse. In a few words, the radiant energy from the sun heats the greenhouse or any other structure where you keep your cacti collection.
A shade cloth reflects the sunlight back or partially blocks it. The percentage of the shade cloth represents the amount of light which it blocks. Then, shade cloth can be in various colors. What is the best shade cloth color for your plants depends on what growth stage the plants are in.
Generally, white shade cloth is best to keep temperatures as it reflects solar radiation. In contrast, black shade cloth absorbs and radiates heat. So it won’t have much of a cooling effect. Despite that, both white and black shade cloths will protect your cacti from direct sunlight.
What percentage shade cloth to use for cacti?
What shade cloth percentage to use for cacti depends on your location. On average, you can use a 40% shade cloth up to 70%. For most locations, you can use a white 50% shade cloth, but if you live in Texas (near Chihuahuan desert) then you will need a 70% aluminet shade cloth.
Many people that use shade cloth for the first time install it on the outside of the greenhouse structure. Although the main benefit of putting a shade cloth on the outside rather than inside is that it blocks sunlight before it enters the structure, a lot of gardeners have shade cloth on the inside.
So, if you want to put shade cloth on the inside of your greenhouse, I would recommend white at 50% as it will reflect heat and cool down the structure. However, if you prefer having shade cloth on the outside, then you can get a black or white shade cloth at 50%.
There will be not much difference between white and black in this case. If you have been looking for a shade cloth online, you know that most of the time black shade cloth is cheaper than white. In terms of materials, both white and black are made of polyethylene.
At the end of the day, it is up to you which option you prefer! Once again, for areas with the scorching sun, I recommend using 70% aluminet shade cloth. In comparison to polyethylene fabric, aluminised shade cloth lasts way longer and withstands severe weather conditions.
Shade cloth is not the only option when it comes to shading a greenhouse or vegetable patches. There are four shading methods in total, although, shade cloth is my favorite!
Use the tips above and you will make your cacti happy for years to come!
Do you use shade cloth for your cacti? If so, what percentage and color? Let me know in the comments section down below!
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Happy Growing 🙂