The ukhouseplants' rule of 'droughts between drenches' strongly applies to all desert cacti. In the spring and summer, allow all of the soil to dry out in between waters for at least a week. During the cooler months of the year, reduce this further to replicate its dormancy period. Don't worry about under-watering, these beauties can last at thirty days without water in most cases! Under-watering symptoms are usually uncommon; however, crispy and stunted growth are possibly due to either forgetfulness or too much sunlight. Over-watering symptoms include root and stem rot, mushy yellow leaves or a rotten stem. These issues can be corrected by removing the plant out from its pot and inspecting the rootball or soil. Are the roots brown and mushy? If so, remove the affected roots and replace the soil with a well-draining potting mix (Cactus & Succulent Compost is best). If the bottom of the stem is mushy, it's game over - the 'heart' of the plant has rotted, meaning that revival is minimal. Cacti are more likely to suffer from over-watering if they're situated in a dark location or in overly-moist soil.
This is not a factor; however, a quick hose down from time to time will reduce the number of dust particles or pests on its body.
The brighter, the better; a shadier spot will slow down growth and increase the chances of root or foliar rot. If it's situated in summer sunlight, never allow long-spelled droughts (of over one month) to take over, as it'll weaken the plant, leaving it dehydrated and sun-scorched. It's recommend to locate a desert cactus next to a north-facing window, or a few metres within a south-facing one. Never situate any cacti too far from a window, as exaggerated phototropism will cause the plant to grow lopsidedly.
Feed monthly all year round using either Cactus or Houseplant Feed. Do not directly apply 'ready to pour' fertilisers into the soil without a pre-wash, as this will lead to burning roots and yellowed leaves.
Over-watering is the most common issue, with typical signs including a softened yellow stem and stunted growth. The soil must have periods of droughts to replicate the habitats of semi-deserts of both Americas, as well as limiting the chance of diseases. Also, avoid waterlogging; there's no point fulfilling the phrase 'drenches between droughts' if the base of the pot is submerged, as root rot will quickly arise. For more information about over-watering related issues, be sure to click on this link.
A pale centre and deformed growth are typical signs of too little light. Offer at least an hour of direct sunlight, especially in the winter months, to provide the vital nutrients that'll be converted into plant sugars.
Alternatively, too much sunlight will lead to sun scorch, with typical signs including browning or crispy leaves, dry leaf-edges, sunken leaves or stunted growth. Although too little light will cause over-watering issues, too much sunlight will negatively affect the plant, too. A location that offers 2 - 4hrs of sunlight a day brings the optimum growth. If it's fallen short of sun-scorch, reduce the amount of sunlight and keep the plant sufficiently hydrated - while keeping in mind 'Drenches Between Droughts'.
Over-supplementing a cactus will bring nothing but grief in the likes of yellowing leaves and weak, dramatic growth. Although a monthly feed is an excellent way to promote healthy, vigorous growth, dry soil and sharp chemicals from the feeds will quickly lead to the burning of roots. The advice for this issue is to pre-moisten the soil beforehand; not only will this remove the chemical-edge found in fertilisers, but it will also adversely remove the chance of root burns.
'Corking', or a hardened brown base (pictured below) is part of the ageing process for a cactus. If those sections are hard and doesn't give way when applying pressure, everything is okay. If, however, the base is soft, action must be taken quickly. Take the plant out of the pot and inspect its root system. If it's brown and mushed over, you'll have to discard it as the plant has collapsed from the inside out. For those that still have good root systems, keep the plant under-watered and provide a bright location with a hint of direct sunlight. The recovery process will be long, and sometimes not even successful - give it a go and see if you can resciciutate it!
Achieving a cactus-bloom is relatively easy once the plant is at least three years old. As ukhouseplants been challenged many times on this subject, we've created an acronym to help you through this process - SHORT. The combination of drying soil, cooler temperatures and dark nights will contribute to better flowers in the following season. Repotting isn't mandatory, but instead might hurt the chances because of transplant shock and stress. The following steps must be taken from autumn to winter, to provide the best possible dormancy period.
Provide a bright location with a few hours of winter sun. Darker settings will significantly reduce the chance of flowers, along with over-watering related issues.
Reduce watering so that the soil becomes fully dry for three weeks, for the prevention of root rot and to replicate its dormancy period.
One or two feeds using Cactus & Succulent Fertiliser is all that is needed for supplementation, as too nutritious soil will reduce the chance of blooms in the following season.
This one is a reminder to reduce everything - especially the temperature.
Reduce the temperature by pacing it in a room within 12℃ - 15℃ (54 - 59℉). As most houseplants are sensitive to temperature change, we can't empathise how important this is to replicate their dormancy period. If all of the steps are fulfilled, an established specimen could produce a vibrant colour of either red, white or pink clusters of flowers on the top of the cactus' head.
|Time of Year||Care Requirements|
|January & February||Resting/Dormancy Period. Reduce irrigations and fertilisation.|
|March||End of Resting/Dormancy Period. Increase waters and feed using houseplant fertiliser at monthly intervals.|
|April||Pre-Flowering Period. Use a potassium-based feed (like Tomato Feed) fortnightly during this period. Water once ALL of the soil dries out.|
|May & June||Flowering Period. Use a potassium-based feed fortnightly during this period. Again, rehydrate once ALL of the soil dries out.|
|July||End of the Flowering Period. Gradually decrease both water and fertiliser intake in the soil. Remove the spent flower as it collapses.|
|August & September||Water once all of the soil dries out. Supplement using houseplant feed or a general plant fertiliser, at monthly intervals.|
|October - December||Resting/Dormancy Period. Reduce irrigations and fertilisation considerably.|
Although cacti have been used for medicinal and decorative purposes for over six hundred years, drawings and other findings can back from 9'000 years ago. Almost all of the 1750-known species originate from the Americas, with only the Rhipsalis baccifera (Africa) breaking this trend. The formal classification of Cacti arose in the 1730's by Carl Linnaeus, who placed the species he knew into two groups - Cactus & Pereskia. Before his book was published in 1753, he re-conjoined the two groups back into Cactus, a Greek word that was first used by Theophrastus (A Greek Philosopher, C. 300BC), describing a 'thornful' plant.
Further Facts about the Popular Genera
10° - 28°C (50° - 82°F)
H1c - can be grown outdoors in the spring and summer in a sheltered location once the nighttime tempreetres are above 10°C. Always perform a pest-check before re-introducing back into the home to avoid an infestation with other plants - most common to look out for are Mealybugs and Vine Weevils.
Reducing this temperate to around 12°C (54°F) during the autumn and winter months will not only help its its dormancy period, but it'll also increase the chance of a bloom in the spring or summer.
Fast growth rate - Saguaro Cactus, Pachypodium, (Carnegiea gigantea), Euphorbia & Bilberry Cactus.
Slowest growth rate - Golden Barrel Cactus, Mammillaria, Aztekium, Ferocactus & Peyote.
Remove yellowed or dying leaves and plant debris to encourage better growth and improve the all-round appearance. Pruning must be done with clean scissors or shears to reduce the chance of bacterial and fungal diseases; remember to make clean incisions as too much damage can shock the plant.
In some cases, you can even graft epiphytic (tropical) cacti into terrestrial desert species. Have a look at the strange image below to be amazed!
Via seed or offset division via 'pups' or leaf cuttings. To learn about the essentials with sowing seeds, be sure to click on this link - Seed Propagation Tips.
Lateral offshoots (Pup) Division - Some species, like Euphorbia, Opuntia, Gymnocalycium, will produce lateral growths that can be propagated in the spring, once they surpass 7cm in length. Wear some protective gloves and place your hand in between the two. While placing your hand closely to the nodal junction, gently push the pup downwards, while supporting the mother plant - you should hear a snap. Cautiously separate both the mother plant and pup's roots systems, keeping great empathise in keeping the roots intact and damage-free. Place the new plantlet a third depth in a well-draining potting mix, much similar to the original soil, and maintain the same care routines. Houseplant compost is acceptable, or you can make your own using multipurpose compost with grit or perlite. Don't worry if the 'pup' doesn't have any roots, these will form later down the line. Make sure not to use a pot that is too big as a ratio of roots-soil that leans towards the latter will cause root rot and eventually plant death. Keep the soil dry and out of direct sunlight for the first two months. When the pup is rooted, increase the light intensity and frequency of waters.
Repot every two to four years using grit or sand-based compost in the spring months - Cactus Soil or a general purpose potting mix with some added grit and sand are best. For matured specimens, introduce more grit to promote a stronger root ball as well as the reduction of potential root rot; click on this link for more information on how to perform the perfect transplant.
Common diseases with cacti are root, crown or heart rot, sun-scald, soft rot, scabs, nematodes, leaf-spot disease and powdery mildew. Keep an eye out for vine weevils (uncommon indoors), spider mite & mealybugs. For more info on how to address any of these issues, hit this link. Identifying Common Houseplant Pests & Diseases
Most varieties are classified as poisonous. If parts of the plants are eaten, vomiting, nausea and a loss of appetite could occur. Consumption of large quantities must be dealt with quickly; acquire medical assistance for further information.
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