There are thousands of different species of cacti in the wild, and two major categories of cacti that are grown as houseplants are the desert and forest cacti. Both species are hardy indoors and require little care; the most common sizes for these groups are small to moderate.
Usually, paddle-, ball-, or obelisk-shaped, desert cacti have spines or hair. The origins of forest cacti are subtropical areas. They thrive in woody sections of temperate forests as well as subtropical and tropical locations, and they resemble other succulent plants like bromeliads. These are climbing, or epiphytic, plants that make great interior hanging plants and naturally cling to trees.
Christmas cactus, a native of Brazil, is the most popular ornamental forest cactus. It blooms in red, pink, purple, and yellow. Among the hardiest houseplants, desert and forest cactus grow slowly and produce stunning blooms.
| Common Name | Cactus |
| Botanical Name | Cactaceae |
| Family | Cactaceae |
| Plant Type | Succulent, perennial |
| Mature Size | 1-96 inches tall, 2-30 inches wide depending on species and cultivar |
| Sun Exposure | Full sun |
| Soil Type | Well-drained, sandy |
| Soil pH | Neutral, acidic |
| Bloom Time | Summer |
| Flower Color | Orange, pink, red, yellow, white |
| Hardiness Zones | 9 to 11 (USDA) |
| Native Area | North America, South America |
Indoor Cactus Care
Desert and forest cactus, which are among the hardest houseplants to care for, have a distinct, stark beauty that makes them a focal point for any windowsill or well-lit space. The following are the primary needs for maintaining an indoor cactus:
- Because indoor cacti need bright sunshine, place them in the brightest position in your house.
- Get ready with loose, well-draining soil or plant in a mixture of cacti.
- Once the soil is entirely dry, just apply water; err on the side of caution.
- When the plant goes dormant in the winter, watering and feeding can be reduced.
- Generally speaking, pruning is not required until growth needs to be controlled.
- Deadheading is only necessary for flowering kinds, as dried flowers usually fall off on their own.
Light
Every day, cacti need four to six hours of direct sunlight. However several varieties of cacti, both forest and desert, can burn when exposed to direct sunlight. Place your cactus next to a window that gets plenty of sunlight. In the summer, it should receive filtered bright light; in the winter, it should receive direct light from a window that faces the south or west.
If your cactus needs lots of light, you can move it outside in the summer, but only if the nighttime low reaches fifty degrees Fahrenheit or higher.
Soil
Fast-draining soil mixed especially for cacti is ideal for growing desert cactus. Additionally, they thrive in ordinary potting soil that has been enhanced in drainage and aeration with perlite, sand, or stones. Although forest cacti can frequently grow quite fine in standard potting mix, they do like well-draining soil.​
Water
When your cactus is vigorously developing and blooming in the spring and summer, give it a good drink every ten days and make sure the water drains completely. Reduce the frequency of watering to once every four weeks (or every six weeks for certain desert species) during the winter rest period. Between summer waterings, the soil should be nearly dry to the touch, and in the winter, it should be mostly dry.
Temperature and Humidity
Temperatures between 70 and 80 degrees Fahrenheit are ideal for cacti. The plant loves a cool-down period during the winter, when temperatures are close to 55 degrees Fahrenheit. A desert cactus is adapted to extremely cold nights in its natural habitat; certain varieties can even tolerate nights as low as 35 degrees Fahrenheit. Nevertheless, winter draft protection is necessary for any indoor plant that hasn’t been hardened off.
Average humidity levels are preferred by cacti, and they are often easy to attain in most homes. Compared to desert types, forest cacti have slightly greater humidity in the air. Therefore, spray your succulent plant occasionally if you notice it wilting.
Fertilizer
Cacti can withstand some of the most extreme environmental circumstances. While not required, any fertilization effort is appreciated. To avoid disappointing results from regular houseplant fertilizers (often caused by an incorrect nutrient ratio), look for a specialist organic cacti fertilizer that has a higher phosphorus content than nitrogen.
Only fertilize your cactus during the growing season, two to three times a year, according to the manufacturer’s recommended dosages. During the winter, cut back on or stop applying fertilizer.
Types of Indoor Cacti
Cacti can be grown indoors in a variety of forms, from those with typical spines to those that resemble other succulent plants. Several popular varieties for indoor growing consist of:
- Native to Northern Mexico, the Bunny Ear (Opuntia microdasys) cactus is named for its stem-like pads, which bear a resemblance to bunny ears. This kind has pads that resemble cotton but are covered with many spines called glochids, or barbed bristles. These bristles should be handled carefully. The Bunny Ears cactus can reach heights of two to three feet and is known for its white flowers.
- With her hair and many spines, Old Lady Cactus (Mammillaria Hahniana) has the appearance of a pincushion. This variety can reach up to four inches in height and eight inches in width. It has round flowers that are an eye-catching purple color.
- Star cactus (Astrophytum asterias), sometimes known as the sea urchin or sand dollar cactus, is a star-shaped mound that blooms yellow. Indoor terrarium gardens frequently include this little type, which grows one to two inches tall and two to six inches in diameter.
Pruning
A cactus usually doesn’t require much pruning unless you’re attempting to manage its development. However, sharp, clean garden shears can be used to remove any dead or damaged pieces.
In order to propagate new plants, gardeners usually merely trim their cacti to get rid of new offshoots, often known as pups. To avoid hurting yourself while doing this, always wear protective gardening gloves.
Propagating Indoor Cactus
You can use the offshoots (also known as pups) that your cactus produces to propagate other plants. While some puppies form along the stem or on the pads, the majority grow at the base of the plant, sharing nutrients and water with the mother plant.
Puppies can be replicated while also benefiting the mother plant’s health through harvesting and propagation. The following is how to grow cacti from their offshoots:
- Assemble the necessary materials: pot, cactus potting mix, gloves, alcohol pads, sharp knife, and rooting hormone.
- Wipe your knife with an alcohol pad, then let it air dry to sterilize it. Wear gloves with protection.
- Find a pup, then use a 45-degree angle to cut it away from its mother at its base so that the wound can be before it rots.
- Give the dog several days (or even up to a week) to sit in a dry location so that it can develop calluses.
- Put the potting mix in your pot.
- After dipping the pup’s cut end into rooting hormone, carefully press it into the growing medium’s surface.
- Mist the pot frequently and place it in bright but indirect sunshine.
In four to six weeks, your new cactus should have sturdy roots growing.
How to Grow Indoor Cactus From Seed
Cacti can be grown from seed, both desert and forest types, but it requires perseverance. You will also need to obtain cactus seeds, which are only accessible from the plant when it blossoms. You can be limited to purchasing packaged seeds from a nursery if certain cacti never flower inside.
Before planting, the majority of cacti seeds must be stratified—that is, tricked into believing they have gone through winter. To achieve this, plant the seeds in moistened peat and refrigerate until they burst open, which should happen in four to six weeks.
Plant the seeds as deep as they are wide in a pot filled with cactus potting mix after the stratification period. After giving them a little water, cover the pot with plastic, set it somewhere bright but out of the direct sunlight. After the majority of cacti germinate in three weeks or less, you can take off the plastic covering during the day. Seedlings should be ready for their own pots in around six months.
Potting and Repotting Cactus
Because they grow slowly, cacti rarely need to be replanted. Actually, being somewhat root-bound encourages better blooming in a lot of cacti species. Only when they require new soil or have rot can cacti be repotted at the start of the growing season.
Put on some protective gloves first in order to accomplish this. After that, take your plant out of its pot and use a fresh trowel to loosen the roots. A quick-draining cactus potting mix should be added to the bottom of a clay or terra-cotta pot. After adding your plant, carefully cover the roots with backfill and water it moderately.
Overwintering
Wintertime special care for an indoor cactus usually entails less, not more, attention. First things first, place your cactus in the window that receives the most sunlight. Because the winter sun is lower in the sky, your cacti will be able to grow and thrive without getting burned. After that, be sure to cease fertilizing during this period of dormancy and cut back on watering to no more than once a month.
Common Pests and Diseases
Mealybugs, scales, fungus gnats, and spider mite infestations can affect any kind of cactus. Shrunken leaves, a coating resembling mold, and the presence of bugs in the soil or on the stems are some of the symptoms. Most of the time, you can use cotton swabs or a sink hose spray to gently remove pests. The majority of plant pests are now resistant to chemical insecticides, therefore applying them inside should only be done as a last resort.
Fungal rot, which appears as dark, sunken patches on the stem that eventually become mushy, can affect overwatered cacti. Your cactus may also leak a dark fluid due to bacterial decay. If the plant exhibits any of these symptoms, cut off the afflicted sections and apply a weak solution of hydrogen peroxide.
How to Get Indoor Cactus to Bloom?
Because most succulents and cacti don’t bloom indoors, it’s a delight to find one in flower. You must replicate the cactus’ native habitat, which calls for warm daytime temperatures and chilly nocturnal temperatures of 50 to 55 degrees Fahrenheit, in order to facilitate the process.
It could be necessary to move your plant to a garage or basement at night if the ambient temperature in your home is warmer than that—something that most home gardeners wouldn’t bother doing.
Cacti also require the right amount of water—not too much, though—and four to six hours of sunshine per day in order to flower. Possibly the most crucial element for flowering is allowing your cactus to go through a dormant phase, during which it receives less water and sunlight. Certain woodland cacti, such as the Christmas cactus, bloom during this time of year.
Common Problems with Indoor Cactus
Overwatering in the winter is the most frequent error made by gardeners with cacti. Rot may result from this at the plant’s base or at the tips where new growth emerges. If the rot gets too bad, you may have to start over from cuttings or throw out the mother plant as a whole.
Because most chemical fertilizers include heavy metals that eventually kill the plant, using non-organic fertilizers might also harm your cactus. Furthermore, physical harm is frequent in cacti due to their lack of protecting bark or leaves, which might result in an infection from a bump. Keep your plant healthy enough that it can develop a callus before becoming infected in order to avoid this.
Also Read: Step-by-Step Guide to Grow and Care for Golden Bamboo Indoors