Cacti are fascinating plants Not only because of their exotic appearance and adaptability, but also because they require very specific care to grow at a good pace. Although they tend to be hardy and minimalist in their needs, if you want your cacti to grow faster and look healthy and vigorous, it's essential to follow certain practices and understand the keys to their biology. Below, we offer a comprehensive, updated and detailed guide with everything you need to know, integrating the most relevant and useful information from experts, hobbyists, and professional gardeners.
Importance of sunlight for cactus growth
Light is one of the crucial factors for the optimal development of cacti.Most species require abundant natural light, preferably between 4 and 8 hours of direct sunlight each dayWhen growing cacti indoors, it's essential to place them near windows or strong light sources. Terraces, balconies, or gardens are ideal for taking advantage of the maximum amount of sunlight possible.
Some cacti and succulents can adapt to less intense lighting., but in general, low light slows growth and can cause elongated, weak stems (etiolation). Observe the behavior of your plant This is the best way to determine if it's getting enough light: a dark green color, compact growth, and the formation of new spines are positive signs. If the spines become weak or the plant grows disproportionately toward the light source, it probably needs more exposure.
In extremely hot climates, it's a good idea to protect cacti from the most intense hours of sunlight to avoid sunburn by using shade netting or moving the plant to the shade for a few hours.
The ideal substrate: key to avoiding waterlogging and promoting growth
Using a suitable substrate ensures that cacti can absorb water and nutrients optimally without suffering from rot problems.Cacti and succulents require a loose, well-aerated, and well-draining potting mix. It's best to use a cactus-specific potting mix, which is usually sold pre-prepared in nurseries, but you can also make it at home by mixing:
- Sifted garden soil (free of heavy organic matter)
- Coarse river sand or silica sand
- Gravel or perlite to improve aeration
Proportions can vary, but a classic mix consists of 2 parts soil, 1 part sand, and 1 part gravel/perlite. For species that require more moisture, such as the Christmas cactus (Schlumberg was), you can slightly increase the proportion of soil.
It is essential that the pots have drainage holes in the base, as this prevents excess water in the roots.
The size and depth of the pot: direct influence on the growth rate
The vast majority of cacti have shallow roots.. By ello, They grow best in wide, shallow potsThis reduces the risk of waterlogging and allows for better utilization of the substrate. Pots that are too deep retain more moisture and increase the likelihood of fungal diseases.
Furthermore, The size of the pot should be proportional to the cactusIf the pot is too large for the plant, the substrate may remain moist for too long, causing root stress. When repotting, try to choose a container that leaves about 2-3 cm of space between the rim of the cactus and the rim of the pot.
Irrigation: frequency, quantity, and techniques to accelerate growth
Watering is one of the most delicate aspects of cactus care.Although they are plants adapted to drought, they need water to activate their metabolism and grow. The key is to water deeply but evenly.:
- Water until water runs out of the drain, moistening the entire substrate well.
- Let the earth dry completely before watering again.
- During the growing season (spring and summer), cacti may require watering every 7-15 days, depending on ambient temperature and humidity.
- In winter, with lower temperatures and less light, watering should be spaced out as much as possible, even once a month, or suspended if the plant is dormant.
In very hot environments or if you notice signs of dehydration (wrinkled or soft cacti), you can slightly increase the frequency, but Never allow the substrate to remain wet for too long..
How to fertilize to stimulate cactus growth
Fertilizer directly influences growth speed and flowering capacity., but it should be done with caution. Cacti store reserves for long periods, so It is not necessary to fertilize frequently or in large dosesFor vigorous development:
- Use specific fertilizers for cacti and succulents, which contain less nitrogen and more phosphorus and potassium.
- If you use universal fertilizers, dilute them to double the recommended dose to avoid excesses.
- Fertilize only during the period of active growth (spring and summer), generally no more than 2-3 times per season.
- Organic compost and well-rotted compost scraps can provide nutrients in a natural and balanced way.
It is not advisable to fertilize if the plant is sick, recently transplanted, or in dormant state.
The importance of periodic transplantation to promote growth
Repotting cacti when they outgrow their pots or the substrate has been depleted is essential to maintain a good growth rate. The The best time to transplant is at the beginning of the growing season., when temperatures begin to rise and there are more hours of daylight. This facilitates early adaptation and reduces the risk of stress.
During transplant:
- Use thick gloves to avoid punctures, especially in species with long spines or irritating juices.
- Be careful not to damage the main roots. If there are any rotten or dry roots, carefully remove them with clean scissors.
- Let the plant dry out of the substrate for a few hours before replanting if you have made root cuts to avoid fungal infections.
- Do not water immediately after transplanting.; wait a few days before doing so to minimize the risk of rot.
Periodic transplanting, in addition to renewing the substrate, stimulates the production of new roots and prepares the cactus for a new cycle of vigorous growth.
Cactus spacing and grouping: how to optimize their development
The way we group cacti directly affects their growth and health.Many people plant their cacti too close together, which creates competition for resources and reduces air circulation. Try:
- Find out the final size of each species before planting them.
- Leave enough space between plants to prevent them from shading each other or restricting airflow.
- Do not place cacti near paths or traffic areas to avoid accidents and damage to the thorns.
- Take advantage of the variety of species to create compositions with different shapes and colors, but always respecting their living space.
Cactus Propagation: Tricks for Growing New, Larger Plants
Vegetative reproduction is one of the fastest and most effective methods to multiply cacti and obtain large specimens in less time. This technique involves obtaining cuttings, sprouts, or segments from the mother plant to root them and create new plants. The steps for multiplying cacti by cutting are:
- Select the appropriate segment: Choose healthy side shoots, segments or "heads" on columnar type cacti or segments on cacti like Opuntia dilleni.
- Cut with a clean tool: Use a sharp, disinfected knife or scissors. For segmented cacti, such as the bunny ear, you can remove an ear with thick tweezers or while wearing gloves.
- Cicatrization: It's essential to leave the cut exposed to the air for a few hours or days so that a callus can form to protect the fresh tissue. This prevents infection and rot.
- Plantation: Place the cutting in well-drained growing medium, lying down or standing up, depending on the type. Don't water until you notice the base is firmly established (this may take days in warm weather, weeks in cool weather).
- Location and initial watering: Keep the cutting in a bright location, but protected from direct sunlight, for the first few weeks. Water only when the substrate is dry.
This method is highly efficient and allows you to obtain multiple specimens from one plant and even rescue a damaged or diseased cactus.
Special care according to the species: Christmas cactus and associated succulents
Although in general the tips for growing cacti faster work for most species, some require slightly different care. For example, the Christmas cactus (Schlumberg was), very popular for its flowering, prefers slightly more organic and humid substrates and doesn't tolerate long droughts like other cacti. Remember:
- Provide a little more moisture, but never puddle.
- Use a substrate with some peat or well-decomposed organic matter.
- During flowering, slightly increase watering and apply a mild liquid fertilizer.
Additional tips to accelerate the growth of your cacti
- Ventilation: Ensure good air circulation around the cactus to prevent moisture buildup and the growth of fungi.
- Optimal temperatures: Growth is fastest when daytime temperatures are between 20 and 30 degrees, and nighttime temperatures do not drop below 10 degrees.
- Cleaning: Remove leaves, flowers, or nuts to prevent pests and encourage new shoots to emerge.
- Comment: At the first sign of disease, act quickly. Cut and remove damaged areas and repeat the healing and rooting process.
- Hanging baskets and vertical gardens: Many species of cacti and succulents, having shallow roots, thrive in these arrangements, favoring expansion and lateral growth.
Why is my cactus not growing or growing very slowly?
Factors such as lack of light, excess water, inappropriate substrate or pots that are too large are usually the main cause of slow growth.. Check out this list of possible reasons and solutions:
- Insufficient light: Move your cactus to a location with more hours of direct light, preferably in the morning.
- Compact or non-draining substrate: Change the mix to a more aerated one with a higher proportion of gravel or perlite.
- Excess or lack of irrigation: Adjust the frequency by observing the condition of the substrate and the appearance of the plant.
- Lack of nutrients: Provides specific fertilizer during the growth period.
- Damaged roots or pot too large: Check the root system and reduce the size of the pot if necessary.
With these adjustments, most cacti will return to their natural rhythm, and you'll be able to enjoy larger, more vigorous specimens in less time.
By integrating all these recommendations and carefully observing the specific needs of your cacti, you'll notice how they respond by growing faster and presenting a healthy appearance, with strong spines, vibrant colors, and the ability to multiply. A thorough understanding of optimal conditions, along with patience and consistent care, will allow you to create a beautiful, long-lasting, and ever-growing cactus collection.