How Does a Cactus Seed Itself?
Though cacti are significantly different than other plants you might have in your garden, they do share some similarities. Like other plants, cacti produce flowers and seeds for propagation. If you already have cacti in your garden and want to start additional plants, you can harvest the seeds for planting by collecting and drying the fruit.
Though cacti may not be the first plant that comes to mind when thinking of flowering plants, all cactus varieties produce flowers of some type. Some cacti produce very colorful and large flowers, such as the orchid cactus (Cactaceae epiphyllum) that features fragrant flowers with an 8-inch diameter. Cactus flowers are large and conspicuous as a means of attracting pollinators, without whom the cacti would be largely unable to propagate and produce seeds in the wild.
To produce seeds, the flowers of a cactus need to be pollinated. For most cactus varieties, the pollen has to come from another cactus plant to ensure genetic diversity. Pollen is typically carried from one cactus to another by insects or birds that visit the flowers in search of nectar, though it is possible to pollinate the flowers by hand using a swab or by removing the pollen-bearing stamen from the flower and inserting it directly into the flower of the other cactus.
Once cactus flowers are successfully pollinated, the seed formation process begins. The seeds develop within a fruit, which, like the flowers, are typically colorful and juicy as a means of attracting birds or other animals to spread the seeds. A single cactus plant may produce up to one million seeds, due in large part to the harsh conditions that cacti traditionally grow in; out of that million seeds, only one or two are likely to grow into a new plant in the wild.
Planting Cactus Seed
In nature, cactus seeds are spread by animals that eat fruit from the cactus or by natural influences such as wind or rain. In your garden, however, cactus propagation isn’t left up to chance. To get the best results, start with a pot filled with well-draining soil such as potting soil designed for cacti or topsoil mixed with sand. Place the cactus seeds on top of the soil, then cover it with a layer of sand no thicker than 1/8 inch. To keep the temperature and humidity even during germination, cover the pot with plastic wrap and place it in a sunny location for two to 16 weeks until seedlings are visible. You should keep the soil moist, but make sure that you don’t oversaturate it.
Depending on the type of cactus you’re propagating, growing from seed isn’t always the best option if you want to add more cacti to your garden. Some varieties take years to grow and may be hard to establish from seed. Rooting a cutting from an existing cactus is significantly faster. To root a cactus cutting, plant it so that the cut portion of the cactus is approximately 1 inch deep in well-draining soil. Keep the soil slightly moist but not more saturated than you would keep a standard cactus. New roots will develop from the cutting to absorb moisture from the surrounding soil, a process that may take up to a few months.
- Texas A&M University Aggie Horticulture: Cactus
- Eduscapes: Cactus (Cactaceae)
- Desert Gardens LLC: Propagating Your Cactus
Born in West Virginia, Jack Gerard now lives in Kentucky. A writer and editor with more than 10 years of experience, he has written both articles and poetry for publication in magazines and online. A former nationally ranked sport fencer, Gerard also spent several years as a fencing coach and trainer.
How Does a Cactus Seed Itself?. Though cacti are significantly different than other plants you might have in your garden, they do share some similarities. Like other plants, cacti produce flowers and seeds for propagation. If you already have cacti in your garden and want to start additional plants, you can harvest …
Growing Cacti from Seeds
Growing plants from seeds is not as hard as you might think, even though many of us have tried and failed! One of the most common mistakes people make is planting the seeds too deeply. It would be best if you only planted seeds deep in the soil as the seed is wide. When seeds are planted too deeply, the tiny plants emerge and begin to grow but do not reach the surface before they run out of stored food. Follow these instructions for growing cacti from seeds, and you will surely be successful.
It is best to use fresh seeds when growing most cacti. Seeds can be obtained from a commercial source or collected from a plant in your collection. Take care when collecting seeds from a cactus collection. Some cactus species hybridize freely, and true seed cannot be assured unless pollination has been monitored carefully.
A good potting mix, amended with ½ its volume of granite, perlite, or pumice for drainage, makes a good mix for growing cacti from seed. The soil must be as pest-free as possible. To pasteurize soil, put it in a shallow heatproof pan, place it in the oven at 300 °F (150 °C) for 30 minutes. Most commercial soils are at least pasteurized, if not sterilized. Check the label.
Be sure that all containers to be used are clean. The type of container is not important, but shallow ones are preferred. Water the soil thoroughly and let it drain completely before planting. Spread the seeds evenly over the top of the soil. Cover the seeds lightly with the mix or very fine sand. When planted, cover the container with any transparent lid. This will retain moisture and allow light to reach the seedlings.
Cactus seeds need both light and warmth to germinate. A sunny window is a good location, but be careful the light is not too strong and therefore too hot. The moisture retained by the cover should be sufficient to germinate the seeds. Most cactus seeds germinate within 3 weeks, but some take much longer, be patient. Once the spines are showing, raise the cover for ventilation during the day. Do not allow the soil to dry out. The amount of water will depend on how much light and heat the seedlings receive. Watch the seedlings carefully. Do not swamp them in puddled water but do not let them dry out completely.
Seedlings are ready to transplant into larger containers when they are the size of marbles, between 6 months to a year after germination. Be sure the soil mix is very well-drained, and the container is no larger than twice the plant’s diameter. Plants can be grown in clumps or groups of 6 to 8 per pot at this size until they are about 1 inch (2.5 cm) across, then separated and individually reported. Lift the small plants carefully from the growing mix, place in the new container, firm the soil around the roots, and water in.
It is usually best to let the young plants recover from transplanting in a shaded area. Even in cacti that naturally grow with full sun, seedlings will be tender to the full sun until they are older. Acclimate a young plant to the sun gradually, beginning when it is about 1 inch (2.5 cm) across. It is often easier to acclimate young plants to the sun in the winter and provide some shade in the summer until they are about 3 inches (7.5 cm) across.
Fertilize young seedlings monthly in the growing season, usually the warm season. Use a formulation specifically for cactus or an all-purpose soluble houseplant formula at ½ the recommended strength.
- Succulentopedia: Browse succulents by Scientific Name, Common Name, Genus, Family, USDA Hardiness Zone, Origin, or cacti by Genus
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Follow these instructions for growing cacti from seeds, and you will surely be successful. It is best to use fresh seeds when growing…