In general, succulents prefer moderate temperatures. Of course,some succulents are frost tolerant, while many are of tropical origins and should not be allowed to go below about 50 F (10 C).The succulents that are commonly used as houseplants will do well at temperatures in the range of 50-80 F (10-27 C) that are typical of indoor environments.
Some succulents will go into survival mode or dormancy when temperatures are outside their comfort zone. But the water stored in their plant cells makes succulents susceptible to damage from the effects of extreme temperatures – especially when such high or low temperatures are paired with high levels of humidity.
Due to their high water content, humidity is not good for most succulents, even within their ideal temperature range. One of the main reasons that succulents do well in most household environments is that they are typically quite dry, with relative humidity levels of 10-30 percent. This is the perfect amount of humidity for most succulent plants, as it encourages both fast drying of the growing medium after watering as well as healthy water storage by the plant.
If your indoor air circulation is lacking and your plant’s potting soil is allowed to remain too moist, you’ll end up with a situation that raises the local humidity around the plant, which will quickly lead to fungal infection and rotting. The one exception is the Christmas cactus, which prefers higher humidity as well as soil that’s kept evenly moist.
Potting soil for succulents should be well draining and fast drying, to prevent problems caused by local humidity, over-saturation of plant cells, and root rot. Sandy soil that’s made up of equal parts organic and inorganic material is a great potting mixture for succulents.The idea is to provide a blend that will hold enough water for your plant to absorb what it needs when you water but will then dry out quickly.
To ensure that there are plenty of air pockets within the soil so as to encourage drying and provide sufficient oxygenation of the roots, include materials such as pumice, crushed granite, bark, or coco coir chips that have larger particle sizes, of around a quarter inch, or 6 millimeters.
Commercial succulent or cactus soil mixtures work pretty well, but they can be improved by blending in some pumice or other pebbly material.
In addition to using a well-draining, fast-drying potting mixture, you may also want to place pebble mulch on top of the soil for a stylish accent to your succulent’s bold form and texture.
With all this talk of the importance of soil that drains well, it may be redundant to add that you should use pots with drainage holes in them for succulent plants. This not only helps the soil dry out quickly but also enhances oxygenation of the roots.However, sometimes aesthetics outweigh everything else, and containers without drainage win out. If this is the case, then be sure to use a pebbly potting material to provide excellent aeration to the roots of you plant. Believe it or not, you can use pure pumice, which is porous, rich in micronutrients, and looks classy inside clear glass. Watering is a little tricky, though, as detailed in the next section.
While most succulents are pretty tenacious in the face of less-than-perfect care in other respects, they will quickly become damaged from over-watering or soggy soil. Succulent plants are built to store water and depend on a cycle of water abundance followed by a period of dryness.
So, how often should you water succulents? The answer is that it depends on a wide range of factors, including the potting mixture, the size of the pot, the type of plant, the size of the plant, the location, the time of year, and the weather. Desert cacti typically require less water than other types of succulents.
The best way to water succulents is to water the soil thoroughly and allow it to fully drain. You should then allow the soil to dry out completely before watering again.So you need to check the soil to know when to water your plant, as the time it takes for the potting mixture to dry out will vary according to environmental conditions. In general, you’ll be watering more often during the heat of the summer, although you’ll find that your plant needs less frequent watering when there’s a lot of humidity, rain, or cloudy weather.
To check the dryness of the potting mixture, insert a wooden stick or skewer through to the base of the pot, leave it for a few minutes, and then remove it and look for signs of dampness. Or, if you’re not afraid of a little dirt, simply poke a finger in and feel how damp or dry it is. Alternatively, you can familiarize yourself with how heavy the pot is when it’s completely dry by feel or with a scale, then use that as a reference to know when your plant is ready for another drink.
While it’s more likely that you’re over-watering than under-watering succulent plants, you’ll know you aren’t providing enough water when you see wrinkling and shriveling or the upper leaves begin to appear crisp and dry.
To water succulents growing in containers without drainage, the aim is to provide just enough water to wet all of the potting material without having water pool at the bottom. To achieve this, start by estimating how much potting mixture there is and measure half that amount of water. If it’s not a clear glass container that allows you to see if any water is pooling, monitor the potting mixture for dryness, keep a close eye on your plant for signs of over-watering, and make small adjustments to the amount of water you pour in until you get a good feel for what the right measurement is.
Succulents are light feeders, so you should only fertilize them once every couple of months from March through September using houseplant food that contains more phosphorus than nitrogen. Dilute the fertilizer by one-quarter the recommended dosage for cacti and by half for other succulents.
Succulents are very easy to propagate. If the plant produces small, bulb-like offsets, simply pinch them off, allow several days for a callus to form, and plant them in soil. To take stem cuttings,use a clean, sharp knife to cut the plant just above a node.
For plants like sansevieria, cut leaf portions of about 2 inches (5 centimeters) in length. Allow the wounds to callus over then bury a small portion of the cuttings in soil, making sure they are right side up, as roots will only form from the bottom part. After planting, keep the soil moist for about four weeks, then use the normal watering method for succulents.
Some succulents can also be propagated by carefully pulling leaves from the stem, making sure to get entire, intact leaves. After allowing them to callus over, set them on top of some succulent soil, and wait for roots to form before watering thoroughly.
To pot a succulent for indoor growing, begin by choosing a container that’s about 2 inches (5 centimeters) wider than the diameter of the plant. Fill the container to about three-quarters full with your well-draining potting mixture and dig out a hole to place the plant in. Then gently spread out the roots of your succulent a bit, making sure to remove any old potting soil that may be clinging to them.
When placing the plant in the new container, cover the roots with enough soil to reach the base of the plant, making sure to leave space below the bottom leaves. Refrain from watering the plant for a week to allow the roots to spread out, unless the plant is very young or you’re propagating new plants.
If you’re creating a succulent container garden, be sure to choose plants that are compatible in terms of watering requirements and rate of growth.
Most succulents prefer to be somewhat root bound, and some will flower more readily when this is the case. So you only need to repot healthy succulents into a container that’s an inch or two larger if they become top heavy and unbalanced.
The other reason to repot a succulent is if the potting mixture has been allowed to remain soggy and the plant has become waterlogged, in which case you should carefully remove the damaged sections with clean gardening sheers, rinse the roots with water, and repot in fresh potting soil that has better drainage capacities.
Repotting should be done in the springtime, when the growth period begins, and never during the winter dormant stage, when the plant is unable to recover quickly.
The main diseases to watch out for in succulents are fungal and bacterial rots caused by too much moisture, which can be prevented by proper succulent care. To save a succulent that has begun to rot, remove any blemished or rotted sections, making sure to cut back to where there is healthy tissue and consider repotting.
Like many other houseplants, succulents are susceptible to infestations of scale, mealybugs, and spider mites. Isolate an infected plant immediately to prevent the infestation from spreading to other plants. If caught early, these sap-sucking pests can be wiped away with rubbing alcohol. Here is an article outlining the common pests and diseases, along with pictures.