Despite the fact that many of us have tried and failed, growing cacti from seeds is not as difficult as you may imagine! Planting the seeds too deeply is one of the biggest errors people make. Given that seeds are wide, it would be advisable to just plant them deeply in the soil. When seeds are sown too deeply, the little plants emerge, start to grow, but are prevented from reaching the surface before their food reserves run out. You will succeed if you follow these guidelines for raising cacti from seeds.
Seeds
Most cacti should be grown from fresh seeds. You can either harvest seeds from a plant in your collection or buy them from a commercial source. When taking seeds from a cactus collection, be cautious. True seed cannot be guaranteed for some cactus species unless pollination has been properly observed because some cactus species easily hybridize.
Soil
Cacti can be grown from seed in a good potting mix that has been improved with 1/2 its volume of granite, perlite, or pumice for drainage. Pests must be kept to a minimum in the soil. Put the soil in a shallow heatproof pan and bake it at 300°F (150°C) for 30 minutes to pasteurize it. The majority of commercial soils have either been pasteurized or sterilized. Verify the label.
Planting
Ensure that all used containers are clean. Although it is not crucial, shallow containers are favored. Before planting, properly wet the soil and allow it to drain. The seeds should be evenly dispersed throughout the soil’s surface. Mix or very fine sand should be used to softly cover the seeds. Cover the pot with any clear lid after planting. The seedlings will be able to receive light and retain moisture as a result.
Germination
To germinate, cactus seeds require both light and warmth. A window that gets enough of sunlight is ideal, but watch out that it doesn’t get too hot from the light. The seeds should be able to germinate thanks to the moisture that the cover has managed to preserve. Be patient; while most cactus seeds germinate in three weeks or less, some take considerably longer. Raise the cover once the spines are visible to allow for daytime ventilation. Keep the soil from drying out. The amount of heat and light the seedlings receive will determine how much water they need. Pay close attention to the seedlings. Don’t drown them in standing water, but also don’t let them entirely dry up.
Repotting
When seedlings attain the size of marbles, which occurs between six and a year after germination, they are ready to be transplanted into larger containers. Make sure the soil mixture has excellent drainage, and that the container’s diameter is no more than twice that of the plant. Until they are about 1 inch (2.5 cm) across, plants can be grown in clumps or groups of 6 to 8 per pot. After that, they can be separated and reported individually. Carefully remove the tiny plants from the growing medium, set them in the new container, compact the dirt around their roots, and water them.
The young plants should ideally recover from transplanting in a shaded environment. Seedlings will be sensitive to the full sun until they are older, even in cacti that naturally prefer it. As a result, gradually expose a young plant to the sun, starting when it is about 1 inch (2.5 cm) across. Until they are around 3 inches (7.5 cm) across, it is frequently simpler to adapt young plants to the light in the winter and provide some shade in the summer.
Fertilization
During the growing season, which is often the warm season, fertilize young seedlings every month. Use a cactus-specific formulation or a general-purpose soluble houseplant formulation at half the advised strength.
How are cactus seeds germinated?
To thrive, cacti need a sunny location in a compost that is very well-drained, like cactus compost.
Select a windowsill facing south or east for the greatest effects. If the windowsill gets too chilly in the winter, you might need to find them another position.
How to plant cacti
Plant cactus carefully at all times. Your skin may sting and bleed from the spines. To avoid harming yourself while planting your cactus, it is a good idea to use everyday kitchen tools like a fork, spoon, and thick tea towel.
Cactus should be planted in a compost that drains very well, such as cactus compost. Alternately, use a multipurpose compost devoid of peat that has been enriched with horticultural grit or vermiculite to improve drainage.
To finish the aesthetic of the pot display, add a layer of horticultural grit or pebbles. Additionally, this stops water from re-splashing on the cactus.
In our No Fuss video guide, Kevin Smith of Gardeners’ World Magazine demonstrates how to use cactus plants to make a visually appealing display. Kevin discusses how to make a decorative mulch, which compost to use, and why salad tongs are the best tool for handling cacti:
Caring for cactus plants
Water cacti in the summer only once a week at most. A decent watering less frequently is preferable to a little-and-often strategy. In the coldest months, you shouldn’t need to water cacti at all.
Cacti should be repotted every two years to receive fresh compost; larger pots aren’t always necessary.
Stan Griffin of Craig House Cacti shares his three best growing advice for cactus plants in this Golden Rules video, including when to water, feed, and when not to. He also offers guidance on how to take cactus cuttings.
Growing cactus plants: problem solving
Cactus plants often pose no problems. Overwatering or inadequate lighting might cause them to decay at the base. The plants frequently die as a result of this.
Spindly growth is possible in cactus plants, although it is simple to fix. In our Quick Tips video, Emma Crawforth from BBC Gardeners’ World Magazine explains everything.
Cactus varieties to grow
- Golden barrel cactus, Echinocactus grusonii, is initially globular but later becomes tall. It has brilliant green stems with spiky ribs that are native to Mexico. In the summer, flowers that are bright yellow bloom.
- The varied cactus Gymnocalycium paraguayense has flattened spines. In spring and summer, it blooms a creamy white color.
- A globe-shaped cactus with brilliant pink, funnel-shaped blossoms is called Mammillaria spinosissima. It has reddish-brown or yellow center spines.
- Rebutia krainziana is a clump-forming barrel cactus that grows little, white areoles and spines in contrast to its dark green, up to 7 cm in diameter stems. Large, yellow or red flowers grow in a dense clump around the main stem in late spring.
You Will Need
- Cacique seed
- clay and plastic miniature pots
- Cactus compost or free-draining compost
- fine grit or vermiculite
- glass sheet
- spoon or fork
- Tweezers
- Gravel
Step 1
A pot should be filled with a loose-draining, moist compost. Firm the surface down gently and level it. Spread your mixture of cactus seeds evenly around the area, being careful not to sow them too densely.
Step 2
Over the seeds, evenly cover the surface of the compost with a thin layer of vermiculite or fine grit. To keep the soil moist, leave the pot wrapped in a clear plastic bag in a greenhouse or on a warm windowsill.
Step 4
Your seedlings should be ready for transplantation the following spring. To gently pry out individual cactus, use a fork or spoon, being careful not to get the spines on your skin.
Step 6
Add compost all around the seedling and give it plenty of water. If more compost is required, add it after placing the gravel around the seedling with the spoon. Keep in a bright area, like a windowsill, and turn on the pot as necessary.
Why won’t the seeds from my cactus grow?
Come cactus are planted at or very close to the soil’s surface because they need light to germinate. They might not have enough light or be too deep. Naturally, they might have been too wet.
How much light do young cactus plants require?
Succulents and cacti typically require between 10 and 14 hours of light every day.
However, there are several things that affect how much light you should provide! What kind of light is it? Is it man-made or natural? Is the light direct or indirect?
You should at the very least be aware of whether your succulent prefers full sun, full shade, or a combination of the two. If you’re unsure, you can presume the plant needs full sun. Cacti and succulents in general are!
Ever questioned why you couldn’t simply leave the lights on all the time? That would imply that it is constantly expanding, right?
Actually, not quite. Like people, plants also require rest. Particularly in the case of desert flora. They engage in CAM photosynthesis, a unique type of photosynthesis. They truly only produce plant food at night, unlike other plants. They would starve if the darkness didn’t exist.
For cactus seeds to sprout, what?
The cactus blossoms produce seeds. If you want to try collecting them, pick the faded blooms and put them in a tiny paper bag. As soon as the blossoms have completely dried out, you can find the seeds. As many seeds are sold online, you can also buy them. Make sure you’re buying from a reliable source by checking. You want seeds that are healthy and likely to grow.
The seed must be awakened from its dormancy before it may sprout. When learning how to plant cactus seeds successfully, there are several ways to eliminate the dormancy factor that are crucial.
Nick the seed’s protective hard shell. Some types of seeds require soaking before planting. One of the seeds with a hard seed coat is opuntia, which will germinate more quickly if the seed surface is scratched and wet. The cold stratification procedure is advantageous for opuntia seeds as well. Follow the steps in this order for the best seed growth:
- With sandpaper, a little knife, or your fingernail, scarify the seed by creating a tiny opening.
- Spend a few days soaking in warm water, changing it every day.
- Put the soil in the freezer or somewhere cool to stratify for 4 to 6 weeks.
Following these procedures, sow your seeds in a moist, well-draining seed starting mix, and then cover them. Avoid planting deeply. Some can simply be placed on top of the soil, like the golden barrel cactus. For others, all that is required is a light soil covering.
Locate away from the sun yet in a bright area. Sunlight with filters is acceptable. Cactus can survive in dry climates, but it needs sufficient humidity to germinate. The soil must be kept wet but not drenched. In a few weeks to a few months, seeds will begin to sprout. A virtue is patience.
According to information on growing cactus seeds, above-ground development takes shape before the root system does, therefore constant hydration and high humidity are required until roots have fully formed. This typically continues until the plant has filled the starter container. Then you can transfer the cactus you started from seed.
How frequently should cactus seeds be watered?
Everything is based on how big your cactus seedlings are. It’s pretty simple to get them to germinate, but the most difficult part is getting them to grow from a seedling into a mature cactus.
If you water your plants excessively, you run the danger of giving them fungus illnesses and other issues that cactus seedlings are particularly vulnerable to. However, if you don’t water the seedlings enough, the tiny, fragile root hairs that are developing on them may dry up and you may lose the seedlings.
<1cm in Width: Keep Soil Moist at All Times
Because they lack the water storage capacity of larger, mature cacti, you must make sure that the soil is always moist when your seedlings are very small, less than 1 centimeter in their breadth. A large, mature cactus may go without water for many, many months. Cactus seedlings can’t do that.
Therefore, at this size, the soil must always be damp but not wet.
There is a distinction between wet soil and damp soil.
>1cm in Width: Water Once a Month
But once they pass that tiny stage—generally when they are one centimeter wide or larger—I start to hold off on watering a little bit longer. I usually only water older cactus once a month and wait until the earth is absolutely dry before I water them again.
For how long are cactus seeds still alive?
It appears that certain cactus species have seed that is viable for many years, like Sclerocactus, whereas others only have seed that is viable for a brief period of time (Frailea, some Mammillarias, etc). There is a good possibility that anything will grow if you have a lot of seed.
How long should you cover cactus seedlings?
The species and environment in which you are growing your cactus have the biggest impact on seed germination time. The likelihood of your cactus germinating quickly increases if you decide to cultivate them inside. Seed germination can take three months to several months indoors since the environment is more controlled.
On the other hand, if you choose to nurture your seeds outdoors, it will take a long time for them to sprout. Cacti cannot thrive here until the conditions are just right for moisture and temperature, as opposed to indoors where you can place them on a windowsill in a light shade.
Cactus seedlings require sufficient attention and security. For the first few years, up until they are around 3 inches long, they require sun protection. It is better to place them indoors or in a shady area to aid with seed germination.
You can start exposing them to the sun when they are approximately an inch long. Go ahead and turn up the light intensity; if they begin to burn, turn them off. When you can comfortable leave them on the windowsill every day for a while, it could be time to move them outside.
Why are the seedlings of my cactus becoming red?
Re: Reddish cactus babies Most likely, you simply experienced too much strong light for too long. They should recover rather quickly if you keep them in less harsh light.
Cacti are able to grow in LED light.
Make sure cacti receive the most light possible whether they are kept inside or outside. If you keep your cacti outside, place them where they will receive the most light possible. Likewise indoors. Ensure they are positioned on a windowsill where they will receive sufficient light.
Your plant won’t live very long if you keep a cactus indoors and put it on a bookshelf, for instance. Although every cactus has a different preference for light, most cacti require strong, direct sunshine. Place your cactus outdoors or on a windowsill, balcony, or unsheltered greenhouse to give it enough light.
Cacti seeds don’t require a lot of light to grow. However, shortly after propagation, seedlings and young plants begin to require significantly more light. A newborn cactus will most likely die now if there is little light.
Artificial lighting for cacti
Use artificial light in place of natural sunlight if you can’t give your adult or young cacti plants access to it. Artificial lighting can be costly, so avoid buying bulbs that burn out quickly and produce little light.
The finest artificial lighting for cacti is provided by LED grow lights like these or fluorescent bulbs/tubes (or even tiny bulbs). Avoid using incandescent or mercury vapor lamps. For instance, 75w grow lights may illuminate a growing space of about 5–10 square feet. The number is frequently higher with fluorescent tubes.
Placing your cactus on a windowsill for light
There are several suggestions that can prevent burns for plants that are kept on windowsills. When it’s really hot outside, sunlight passing through windows will raise the temperature behind the glass by about 50 degrees Fahrenheit while keeping the interior temperature substantially lower.
Your plants may be severely burned by these intense solar rays. So, if it’s over 100 degrees outside, make sure to place your cactus on a windowsill where it is protected from the sun. Cacti with fewer or smaller numbers of spines require greater protection.
This is especially true if your cactus is located on a windowsill facing south, where the sun shines the most. You can shift your cactus to an east or west facing windowsill during really hot weather. If you have a balcony, you can put your cactus there as well. Try to move your cactus outside during the summer months if you can, as windows obstruct the majority of incoming light.
Cacti kept indoors in winter
You’re undoubtedly wondering, “How can I give my indoor cacti light in the winter? So, in the winter, you should put them on the window sill with the most light—often the one that faces south—and give each cactus enough room to get as much light as possible.
Additionally, make sure the windows are clean. Wintertime window dirt accumulation can obstruct up to 25% of entering light.
Protecting your cacti from burns after the end of winter
The majority of cacti grow in environments where they are exposed to natural sunshine all year long. Your cactus may experience burns after the winter if you live somewhere with cold winters and few hours of sunlight. Your cactus haven’t spent a lot of time in the sun over the winter, so when they are suddenly exposed to strong solar rays, they may burn.
For instance, sunshine hours begin to rise in various states of the United States in March or April. Additionally, if you don’t protect your cactus from such intense sunlight, they will burn. The epidermal tissues on the stem may experience necrosis (death), which would impede breathing and metabolic functions. So a burned cactus may even perish or at the very least lose the majority of its spines.
So, how can you keep your cactus from getting burned after the winter? Your goal is to minimize the quantity of light reaching your cacti rather than completely block it. You can accomplish this by affixing some kind of plastic sheet, paper, or even gauze to the glass side.
Do all cacti need bright and direct light?
No, not all cacti require direct, bright light. Because they can be killed by direct sunlight, certain cacti also prefer bright but indirect light. There are some cacti, though, that detest strong light and are severely harmed by it.
For instance, the epiphytic cactus genus Rhipsalis prefers shade and primarily inhabits tropical rainforests despite detesting intense, direct light. There are about 35 different species of Rhipsalis, with the mistletoe cactus, or Rhipsalisbaccifera, being one of the more well-known varieties.
Some cacti, such as those in the Mammillaria genus (including the globe and nipple cactus), barrel-shaped cacti, tiny cacti of the Gymnocalycium genus, or chin cacti, like intense light but may tolerate partial sun.
Let’s not forget that even cacti that like strong, direct light occasionally require a period of low light. After repotting or after administering parasite treatments, protect these light-loving cacti from harsh, direct light. The transitional time following winter is similar.
Cacti and ventilation
As well as dry air, your cactus require sufficient airflow. Make sure to leave a window open if you are keeping your cactus on a ledge so that it may get fresh air. Additionally, for good airflow if your cacti are in a greenhouse, be sure to open a vent (or have an automatic vent).
A greenhouse needs to be properly ventilated, especially in the spring and summer. High humidity and stagnant air are toxic to cacti. In order to give your cactus more fresh air throughout the summer, it is typically a good idea to bring them outside.
Cacti temperature needssummer and winter
High summer temperatures typically cause cactus in their native habitat to go dormant. To endure the intense heat, they now slow down their growth.
And cacti begin to grow as soon as it starts to rain and get cooler. You don’t need to make any changes if your state or country experiences consistently warm winters and hot summers, along with frequent rainfall. Again, the type of cacti will determine everything.
However, if you reside somewhere with chilly winters (like the majority of US states or the UK), you must allow your cactus to grow in the summer and rest in the winter. This is due to the fact that your cactus cannot grow in the dark winter months.
Therefore, if you live somewhere with a chilly winter, you must lower the temps to between 45 and 55 degrees Fahrenheit in order to aid your cactus in going into dormancy (7-10 degrees Celsius).
You will also need to lessen how often you water (once in a week or so). Temperatures must be lowered. Since if you don’t, your cactus will dry out because they will have to evaporate water to stay cool. Additionally, keeping your cactus warm indoors will keep them from falling dormant. even have winter blooms on some cactus.