Fertilizer for christmas cactus

Christmas Cactus

The Christmas cactus (Schlumbergera bridgesii) blooms for a long time indoors with some of the most exotic-looking flowers in the plant kingdom. This cactus is a very popular plant, but most people are not aware of its special needs. Not all cacti are native to arid desert climates and require infrequent, sparse watering. The Christmas cactus actually calls the tropical rain forest home, and thus needs watering when the top inch of soil in the container feels dry to the touch.

Soak the soil until water runs through the pot’s drainage holes; wait a few minutes; and then discard any excess water that has accumulated in the drip pan beneath the pot. A water-soluble fertilizer recommended for flowering houseplants can be applied during its active growth, but be sure to follow the directions on the fertilizer container regarding the amount and frequency of application.

CHRISTMAS CACTUS CARE

The Christmas cactus prefers humid conditions, and homes are often dry. One way to raise the humidity — just for your cactus — is to place the pot with its drip pan on top of a small container filled with pebbles. Pour water over the pebbles, but do not allow the water to rise above the bottom of the top layer of pebbles. The water will evaporate, increasing the humidity around the cactus.

Temperature and day length provide crucial bloom triggers for the Christmas cactus. The term for this response is “thermo-photoperiodic.” Flower buds will form if one of the following conditions is met:

  • a cool night temperature between 50 to 55 degrees
  • 13 hours of uninterrupted darkness (if the temperature is between 55 and 70 degrees)
  • 15 hours of darkness (if the temperature is above 70 degrees)

Uninterrupted darkness means NO light during the dark period, including lamp light within the home. Cover the cactus with a black cloth or plastic bag, or place it in a closet. Pay attention to the light schedule, and do not fertilize or overwater.

PLAN FOR BLOOM

When do you want blooms — for Christmas or Thanksgiving? Count backward eight weeks to determine the autumn date to begin to prepare the plant for reblooming. When buds appear, increase the number of times that you water, but not the volume of water used. Too much water may cause buds to fall, as will moving the pot around. The Christmas cactus will remain in flower for four to six weeks, with each flower lasting six to nine days. After the plant has flowered, prune back each stem by pinching off enough sections to achieve a uniform habit. Resume normal watering and fertilization when new growth appears.

Christmas cacti require direct sunlight, but take precautions against the burning midday summer sun: If you choose to leave your plant indoors during the warm months, move it a few feet away from the window to avoid burning the stems. If the plant is moved outdoors, it still needs protection when the sun is at its zenith.

The spectacular show of flowers will be well worth the effort!

When it comes to bringing the outside in during the holiday season, there are no hard and fast rules. Some people love a small Christmas tree. Other folks take on a decidedly more-is-more philosophy with multiple 12-footers scattered throughout the house, all of them fully decked out in Christmas tree trimmings. Some lucky revelers with green thumbs showcase their skills with a swath of well-tended red poinsettias lined up both inside and out. When it comes down to it, there are a ton of Christmas-y plants—something for everyone! And while some of these perennials aren’t exactly “traditional” holiday trimmings, they still deserve a place on your “nice” list.

Case in point: the easy-to-care-for Christmas cactus! “But wait,” you’re saying. “What’s so Christmas-y about a cactus that sprouts pink, fuchsia, white, and bright yellow blooms?” We’re glad you asked. First of all, some of our favorite holiday decor consists of colors that span the rainbow (not just red and green!). And even better, the cactus is the best kind of Christmas gift because with a little TLC, it will shine and bring joy for years to come. But knowledge is power, so we’ve rounded up the answers to the top questions to keep that Christmas cactus holly jolly rather than ho-hum.

7 Steps to Make that Christmas Cactus Bloom Organically

Does this sound familiar? You are picking out the perfect cranberries in the grocery store for your flawless holiday cranberry sauce when you notice a beautiful Christmas cactus in full bloom calling your name in the Flower section. I am a sucker for this section myself! How dare these grocery stores tease us with perfectly-placed blooming plants right where you can’t resist buying them! 🙂 Buying that beautiful Christmas Cactus in the flower aisle of the grocery store

What you don’t know, however, is that the propagators of these plants have “forced” those flowers & plants to bloom beautifully so they pop for you on display. They have “babied” the plants in greenhouses with perfect humidity, lighting & moisture conditions feeding the plants with high nitrogen or phosphorus fertilizers so the leaves or flowers are at their absolute best to entice you.

That’s great news right…so why does that matter? Well…because you fall in love with the plant, take it home & a couple days later sulk over your morning coffee as you’re watching that beautiful plant drop its blooms right in time for that big holiday meal with the family! Such is typically the case with higher maintenance specimen like the Christmas Cactus, Kalanchoe and Gerbera daisies to name a few…You know what I’m talking about – we’ve all fallen for it at one point in time!

So why do the flowers drop after you bring them home? A dead Christmas Cactus that has dropped its blooms and gone through shock

The fact is…it could be many things, but one of the 3 bolded bullets below is most likely the culprit!

  • Too much direct sun exposure
  • Too much windy draft exposure
  • Climate shock (in transporting the plant from the store to your home or from outside to inside, especially in the winter)
  • Not enough humidity
  • Plant disease
  • Malnutrition, or simply
  • The plant was bought at the end of its blooming cycle

So, given the holidays are upon us and the popularity of Christmas Cacti this time of year (and hence an increase in your indoor gardening stress levels), we decided to save many a heartbreak this year and write a simple guide on how to nurture that Christmas Cactus back to health organically during these cold winter months (for us Northerners anyway…Southern hemisphere readers can read this article for fun while you’re watching your Crotons and Cannas grow…we’re not jealous – well, maybe just a little!)

Would you like Christmas Cactus blooms like ours below? We thought you might…so listen up!

Beautiful Christmas Cactus with magenta blooms grown with Earthwormtec’s all-natural EarthPods flower food

First of all, know that while the Christmas Cactus is a succulent – it is NOT a desert plant but a tropical plant (A-ha!! That should flicker some green thumb light bulbs out there!! It matters a lot because these two climates couldn’t be more different from each other!). In fact, the Christmas Cactus grows predominantly amongst the nooks & crannies of South American rain forest trees where they feed on debris (or should we say nature’s compost? hint…see #7 below). They thrive in filtered light, humid, & well-drained but moist conditions.

Second of all, the Christmas Cactus needs a period of about 8 weeks of rest with chilly temperature (ideally between 50 & 60 degrees) & darkness leading up to a re-bloom. This is one of the reasons it is nicknamed a Christmas Cactus! Think about it…we start to lose daylight hours as the nights get longer and colder in the Autumn months. That happens naturally about 2 months before Christmas which happens to correspond to the approximate amount of time that a cactus needs to rejuvenate. (So, sure I suppose you could stick the plant in a controlled 50 degree cooler and a dark closet 12 hours a day for 2 months…but why not just let nature take its course and not go too crazy!)

Now that you know the 2 most important facts…on to the list!!

7 Easy Steps to make that Christmas Cactus Bloom Organically:

1) The Christmas Cactus actually likes being a bit root-bound (we’ve had ours in the same container for years)

* You can transplant it into a bigger container and you’ll get a larger plant (but it’s not necessary for years to come if you want to keep it on your kitchen table)

2) Make sure your Christmas Cactus is positioned in a fast-draining container (think somewhat similar to orchids)

* Add vermiculite or perlite to your potting soil (depending on the blend you use!). Earthworm castings are very useful for this as well – more on that below!

3) Control the amount of water you give the Christmas cactus

* More during bloom season (it needs moist soil when flowering), less when it’s resting (you can keep it on the dryer side) ** We allow some ice cubes to melt slowly on the top soil every couple days when it’s not in bloom (great way to not overwater it!)

4) Provide humidity

* Fill up a spray bottle and mist the plant every couple days

5) Keep the plant in a consistent climate away from drafty areas

* This one is important – Any sudden change in temperature or draft might cause the cactus to drop its blooms especially when it’s growing!

6) Clean up the plant once it has bloomed & root some cuttings

* This is the time to trim back the plant if you like to keep it smaller (just snap off segments) ** Take this time to take those extra segments and place them in a shallow bowl of water or moist potting soil so only the bottom touches – you’ll see roots develop over the next few weeks (we always make this best practice to do anyway in case something goes wrong with the parent plant)

7)Lastly, DO NOT forget to feed your Christmas Cactus some organic plant nutrients

* Many people completely forget to feed their plants and then wonder why they don’t continue to flourish

** The fact is you can’t expect your favorite plants to continue to thrive & bloom with just watering. Over time the nutrients & minerals in your houseplant & flower pots get depleted as your plants utilize them. You need to replenish those nutrients from time to time by feeding an organic fertilizer that infuses your soil with new nutrients & biological life, or by doing it the hard way and completely repotting your plants with fresh soil.

*** If you want to try the easy method – check out our variety of natural plant and flower food products that work tremendously well on Christmas Cacti and every other plant or flower you may have in your home. Easily push in just 1 or 2 of our EarthPods® organic plant fertilizer capsules into the soil near the roots of your Christmas Cactus every couple weeks – a little goes a long way! If you want to feed your Christmas Cactus while you water it – you could also just drop 1 of our TeaDrops® plant food steeping packets into 1 to 2 gallons of distilled water for a day and then water or spray this liquid fertilizer on to the leaves and roots of your Christmas Cactus once per week. Our organic fertilizer products will work wonders for your Christmas Cacti and all your other flowers and houseplants (as well as your Orchids).

    • Our plant food will re-balance the Ph level of your soil
    • Our plant food releases natural macro & micro nutrients as well as trace minerals slowly to the plant in a form it will efficiently absorb
    • Our plant food helps in controlling drainage, aeration & holding moisture giving you some room if you under- or over-water your plant
    • Our plant food provides an all-natural beneficial biological root support to help your plants become more tolerant of shock & disease
    • And let’s not forget…Our plant food is 100% organic & made in the USA by nature’s oldest fertilizers and rototillers…the earthworms!

Lastly – After the blooming period ends, water the Christmas Cactus sparingly, let your plant rest and continue to let it be the main attraction in your house as a houseplant (or outdoors in the summer). In the Fall right before the first frost hits, bring it inside and put it in a darker room for several weeks (it doesn’t have to be in the closet or the basement as some other articles suggest, just a room where you’re not always turning the bright lights on all the time)! You’ll start to see little buds form and you can come back to this blog post and comment how we made your day! 🙂

If you liked this article – you might also like our article on Orchid Care. Don’t forget to subscribe your email to our newsletter in the lower right hand corner of our website to get notified when we post new articles to our gardening blog and even check out our instagram posts where we post a lot of gorgeous flowers & plants grown with our organic fertilizer products.

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Happy Holidays & Happy Gardening Everybody!

You just brought home that cute little cactus that you’d been eyeing at the market. Or maybe it’s a jade plant that you want to grow lush and green and fill in space in your yard. Perhaps it’s the fractal-like aloe polyphylla, or for that matter a good aloe vera plant. Whatever your choice, you’ve now got a succulent plant. But what do you do to ensure its longevity and beauty in your environment? What fertilizers are safe for succulents, and are there any that aren’t? And most important, what exactly is a succulent, anyway?

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Let’s explore all of these things, and ensure that your drought-tolerant garden is going to be phenomenal in the future!

  • Top Choice: Espoma Organic Cactus Food (1-2-2)
  • Slightly Stronger: Schultz Cactus Plus (2-7-7)
  • Compost Tea Option: Malibu Compost’s version
  • For Indoor Succulents: Miracle-Gro’s succulent formula

What Is A Succulent?

The term “succulent” is one which is really hard to define. Completely unscientific, it generally refers to any drought-tolerant plant that has fleshy leaves, stems, or roots. The term covers a wide variety of plants because of that, and they often have an assortment of care requirements to go along with it.

The one thing which all of the plants tend to have in common is the ability to store water for times of drought. Whether it stores it in its thick and rubbery leaves, inside its central barrel-shaped stalk like some cacti, in mucilaginous liquids throughout the plant structure, or in its large root system, there is a method there to store water. This tends to lead people to believe that they don’t need as much water as other plants, but that’s not true. They like water just as much as every other plant. They just know how to save some for later!

There are some plants, such as the Tillandsia species of bromeliads, who fall into the succulent range of plants as water-storers. However, as these “air plants” have very different root structures (and sometimes no roots at all), let’s focus on more standard succulent varieties such as Schlumbergera (also called Christmas cactus), aloe vera and other aloes, Crassula ovata (also called jade plant), and other common garden-center choices for succulents.

Basic Succulent Care

Overall, most succulents prefer a very well-draining soil mix. Since they tend to grow in locations where water is not available for long stretches of time, a lot of commercial potting mixes are just too moist for their liking. Adding some coarse perlite to your soil is a great idea, as it helps ensure that it drains easily.

For people in areas of the world where it’s cold in the winter, it’s a good idea to plant your succulents in pots that you can bring indoors during the cold months. Succulents are particularly prone to freezing damage, as the water that they’ve stored easily turns to ice.

In hotter climates, succulents can actually benefit from a bit of shade. While most people think of desert sun blasting down when they see a succulent, the truth is that many of the varieties that are widely available don’t come from a desert environment. Succulents grow in tropical regions as well as arid deserts, and also may come from sandy mountain areas. Having some partial shade during the hottest part of the day can ensure your plant stays green and doesn’t get sunburned if it’s a young plant, and if it’s older, it can help keep it lush-looking with nice, plump leaves.

Aeration is also important. While a lot of smaller succulents look great in a grouping, and can grow that way, be sure that there’s enough room around each plant to ensure adequate airflow for every plant. They need to breathe. It’s a good idea to repot your succulents every 2-3 years and to separate plants that have gotten too crowded.

Where most plants require regular watering, your succulent can survive for a bit longer without it. However, this doesn’t mean it doesn’t require water at all, just that it will look good for a longer period before wilting (and yes, you can actually cause your succulents to wilt if they’re under-watered enough). As a good rule of thumb, water your succulents thoroughly on a regular basis, but make sure that once the soil is moist, it drains out and doesn’t remain pooled around the plant.

Over-watering is surprisingly common in succulents, but that’s usually the fault of the soil, not the actions of the gardener. If you have it planted in the right place and with the right soil, it should flourish.

Fertilizing Your Succulents

To use the jade plant I mentioned earlier as an example, let’s say you have a smaller succulent and you want to encourage healthy growth. How do you do that?

As succulents tend to hold water, they also can hold a reasonable amount of dissolved nutrients as well. Over-fertilizing your succulent may cause it to try to grow too quickly. Since they are much more robust plants, this can make your jade plant look weedy or stringy. The stems will be weak, the leaves may be smaller and more flexible. So you don’t want to over-fertilize.

But you also don’t want to under-fertilize. If your soil is well-draining but sandy in your garden, under-fertilization can cause the plant to sit in what appears to be a state of suspended animation. It won’t look bad, but it won’t be getting any larger, nor will it typically produce flowers that way.

The goal is to give it what it needs… but just barely enough, so it will grow at a normal rate and be able to manage its own weight and size as it develops. Most succulents can survive without fertilizer, but that tiny boost is enough to convince the plant that it’s in the perfect place for it to get larger.

What Fertilizer To Use

There aren’t a whole lot of generic succulent fertilizers on the market, and that’s in part because there’s such a diversity of them that it’s hard to pinpoint what to use without knowing the specific plant you have. As a lot of garden centers have trays of plants that are just labeled as “assorted succulents”, that can be a problem!

If you can, visit your local succulent club and identify the type of plant that you have, and you can learn from there what the ideal fertilizer mix is for your species. It’s going to be different for a small aloe vera plant than it will be for a large jade plant or a cholla cactus.

But if you don’t have a succulent club, and just can’t identify your plant’s species on your own, don’t fret. You can use a standard, balanced fertilizer for your succulent, just in a smaller quantity. I typically use an 8-8-8 all-purpose fertilizer concentrate. Make a batch up at its normal strength, then dilute it by adding 2-3 times the amount of water, and use that to fertilize with. Once a month is usually enough at that strength.

When You Need A Special Fertilizer

If you’re trying to encourage flowering (which can be really nice, especially in species like the Christmas cactus), you may be tempted to get a special fertilizer. While nitrogen encourages growth of the plant itself, phosphorous and potassium are the ingredients that tend to inspire the plant to bloom, especially the phosphorous.

There are varieties of fertilizers available on the market as “cactus fertilizers”, both organic and inorganic, which are low-nitrogen, high-everything else blends. However, the majority of these are designed to be used straight out of the bottle and far more regularly than other fertilizers, which means they’re already significantly diluted down. Be careful when you’re shopping!

An exception to this rule is Espoma Organic Cactus Food, which is a concentrated liquid fertilizer. When you dilute it with water, it dilutes to a 1-2-2 fertilizer. You can fertilize with that once a week to twice a month with no problem, and it promotes growth and blooming quite well.

Another liquid fertilizer that is slightly more potent is Schultz Cactus Plus, another concentrate which dilutes down in water to a 2-7-7 range. This works especially well to promote blooming, especially in Christmas cactus and other heavily-flowering varieties. It only takes a few drops of this along with your water to do its job, and is something that’s used on a monthly cycle.

Unless you’re trying to promote flowering, these succulent fertilizers aren’t going to add a whole lot of benefit to your plant, and non-flowering succulent varieties aren’t going to need the extra-high levels of flowering nutrients. In those situations, just opting for a balanced fertilizer and diluting it down yourself will be just fine.

Other Fertilizer Options

If you want to try a non-fertilizer alternative, compost tea is a good option. You can either make your own from compost in your own compost pile, or you can purchase compost teabags like Malibu Compost’s version. Premade concentrated compost teas are also available. Compost tea not only provides nutrition to the plant, but it offers nutrients to beneficial soil microbes which help to protect your succulent from pests and soil problems.

If you’d prefer a granular slow-release fertilizer to a liquid fertilizer, you can use almost any balanced NPK fertilizer for them. However, cut the quantity in half from the recommended amount before adding it around the plants, because they really don’t need all that much fertilizer to thrive.

For people who grow their succulents indoors, it might be preferable to opt for the chemical fertilizers over an organic. Many organics have a distinctive aroma that might not be preferable inside. So if you keep indoor succulents, you may wish to consider something along the lines of a popular commercial brand like Miracle-Gro’s succulent formula. It isn’t as pungent in your house!

How To Fertilize Your Succulents

It’s important that you pay attention to how you’re fertilizing your plants. Since some succulents only encounter rain in short bursts, they may not be accustomed to getting wet. Other varieties are jungle-dwelling types which experience water more as a mist rather than regular rainfall. But in all cases, you want to avoid putting the fertilizer on the plant itself.

Most fertilizer blends, especially the liquids, can cause negative results when they’re spread across the leaves or flowers of succulents, and the nutrition isn’t absorbed that way. Feeding your succulents should always be done at the ground level, and ideally all around the outside of the plant over the root mass. Spray directly onto the soil using a garden sprayer, and being careful to try to not splash any onto the succulents directly. You can also use a backpack sprayer for this purpose!

For plants which are more densely packed together, using something like an indoor watering can is a good idea. The slender nozzle of the watering can provides an easy way to keep your plants from getting directly splashed, and helps you to direct the fertilizer at the roots of the plant where they can do the most good.

If you are in an environment that has cold winters, you will want to stop regularly fertilizing for the cold season. Many succulents tend to go into a dormant state in cold weather. Giving them fertilizer in the fall and winter months won’t benefit the plant during that time.

Once spring comes, that is the time to begin fertilizing again, and spring is also an excellent time to separate and re-pot any plants which have become crowded, as it gives them time to establish themselves again before the heat. If you opt to re-pot your plants in the spring, do that first and fertilize afterwards, as it encourages them to wake back up and start to grow once more.

There are winter-growing succulents in some environments, especially those which don’t get hard freezes like parts of California. These can be fertilized year-round, but they tend to do their major growth during those winter months. For those plants, it’s best to fertilize in the fall or early winter, and then check their growth to decide if they need to be fertilized again in the spring.

Frequently Asked Questions

Q: Is it okay to fertilize my succulents more frequently?

A: Depending on the variety of succulents you have, and the environment in which you live, you will need to establish what works out best for your plants. The nursery industry considers succulents that have been consistently fertilized to be “soft” plants, where those that are irregularly fertilized are “hardened” plants. This mostly refers to how well they will hold up in less fertile conditions. Hardened plants tend to live longer and take more abuse, but soft plants can be incredibly beautiful, so it really depends on how much you feel like babysitting your succulents. Too much fertilizer won’t kill your plant, but it might cause irregular, wiry growth in some species, and it might not be as visually appealing.

Q: Are there any succulents that don’t need fertilizer?

A: Technically, no succulent really needs fertilizer if they’re in reasonably good soil. However, they can certainly benefit from it. If you add a top-dressing of a nice, rich compost to your potted succulents once a year, it’s quite likely that they can survive without fertilizer at all, although they may fall under the “hardened” status mentioned in the last question. Most of the more compact succulents also do well in low fertility situations, so if you have smaller, tightly-compact plants, you may find that they’ll be just fine without fertilizer at all.

Hopefully I’ve answered all of the questions you might have about fertilizing your succulents. Whether they’re large or small, cacti or aloes or some unusual tropical, succulents can be a great addition to your landscape, and keeping them healthy is a breeze! What’s your favorite succulent plant, and what sort of fertilizer do you use? Let me know!

The Green Thumbs Behind This Article:
Kevin Espiritu
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Christmas Cactus (Schlumbergera bridgesi) is a favorite holiday season house plant, but one which needs careful attention to details if it is to flower again the next year. It is closely related to Easter Cactus (Schlumbergera gaertneri) and Thanksgiving Cactus (Schlumbergera truncatus), all with fleshy, flattened, segmented joints and showy flowers ranging in color from white through pink, red and purple.

These cacti are epiphytes, which means that in their native habitat, they live in the crotches and bark of jungle trees. This is why they do best when grown in a light, porous, organic potting soil mixed with sand to provide excellent drainage.

When the flowering period is finished, an active growth period will begin. Keep the plant in a sheltered place until danger of freezing is over. Water carefully, keeping in mind that overwatering is the major cause of failure with Christmas cactus. Soak the potting medium when watering, and then allow the plant to become almost dry before watering again.

I have good success growing mine outdoors during the spring through fall in the bright, but indirect light found under tall trees, which is probably not too unlike the conditions where they are found in nature growing on the trunks of trees!

Fertilize with any water‑soluble, complete fertilizer with trace elements while it’s actively growing. Occasionally, leach out excess fertilizer salts with plain water.

Christmas Cactus will thrive in a well‑drained, sterile potting medium high in organic material. A little sand may be mixed with the medium to provide weight, important as the cactus increases in size. A pH of 5.5 to 6.2 is considered optimum for growth.

Although a temperature of 70 ‑ 80 degrees F during the growing season is considered ideal, plants will tolerate our outdoor East Texas temperatures in the 90 to 100 degrees F range, although growth may be slower. Slowly reduce water and fertilizer in August in preparation for the beginning of flower bud development, which is regulated by the shortening of fall days, along with cooler night temperatures. By late October and early November buds should be visible. Maintain bud set by adequate watering (not too wet or dry), taking care not to expose the plant to cold drafts, unvented heaters, or rough handling. Night temperatures above 70 degrees F may inhibit bud development.

I have had no trouble getting my Christmas Cactus to rebloom by keeping it outdoors until the night temperature gets into the 40’s. The cooler days and nights of fall, coupled with the longer nights combine to trigger flowering right on time, if not a little early for the holiday season.

As the plant becomes larger, short segments may be broken off and rooted in a loose, sandy medium very easily. Mealy bugs, scale and aphids may be rubbed away with a cotton swab dipped in alcohol. Use stronger controls such as houseplant insecticides only if the infestation appears to be gaining the upper hand. With good tending, Christmas Cactus should live for many years.

Thanksgiving & Christmas Cacti

Thanksgiving cactus with peach-colored blossom.
James Blake, ©2011 HGIC, Clemson Extension

Thanksgiving cactus (Schlumbergera truncata) and Christmas cactus (Schlumbergera x buckleyi) are popular, fall- and winter-flowering houseplants native to Brazil, and are available in a wide variety of colors including red, rose, purple, lavender, peach, orange, cream, and white. These Schlumbergera species grow as epiphytes among tree branches in shady rain forests, and their pendulous stems make them a great choice for hanging baskets.

When grown under normal night length conditions, Thanksgiving cacti normally flower near Thanksgiving approximately a month before Christmas cacti bloom. Another member of the group sold as holiday cacti is the Easter cactus (Hatiora gaertneri; synonym Rhipsalidopsis gaertneri), which flowers primarily in the spring and sporadically throughout the year with pink or red flowers. Because of its bloom time, the Thanksgiving cactus is most predominately encountered for sale during the winter holiday season. Flowering can last up 7 to 8 weeks if the plants are kept at 68 ºF.

To distinguish between the Thanksgiving and Christmas cacti, look at the shape of the flattened stem segments, which are botanically called phylloclades. On the Thanksgiving cactus, these stem segments each have 2 to 4 saw-toothed serrations or projections along the margins. The stem margins on the Christmas cactus are more rounded. Note that there are no true leaves on either of these holiday cacti, so photosynthesis occurs within the green phylloclades.

A second method to distinguish between these two Schlumbergera species is based on the color of the pollen bearing anthers. The anthers of the Thanksgiving cactus are yellow, whereas the anthers on the Christmas cactus are purplish-brown.

Culture

Thanksgiving cactus with pale pink blossom.
James Blake, ©2011 HGIC, Clemson Extension

Light & Temperature: The holiday cacti grow best in light shade. Full sunlight is beneficial during fall and winter, but bright sun during the summer months can make plants look pale and yellow. Ideal spring and summer growth occurs at temperatures between 70 to 80 °F during its growing season from April to September. During the fall, the Thanksgiving and Christmas cacti depend upon shorter day lengths (8 to 10 hours) and cooler temperatures to set their flower buds. Do not let temperatures rise above 90 °F once the flower buds are set in the fall. Continuous warm temperatures can cause flower buds to drop. Do not leave these cacti outside if temperatures will drop below 50 ºF.

The secret of good flower bud production during the fall involves temperature regulation and photoperiod (length of day and night) control. To initiate flower buds the plants need:

  • Bright light.
  • Long nights. Fourteen hours or more of continuous darkness each day is required before flower bud set will occur. Long nights should be started about the middle of September and continued for at least 6 continuous weeks for complete bud set. Note that as little as 2 hours of interrupted lighting will inhibit flower bud set. Buds normally will be visible in 3 to 4 weeks. The photoperiod has no effect on flowering once the buds are set.
  • Fall growing temperatures should be kept between 60 and 68 °F, but as close to 68 ºF as possible for maximum flower production. Plants grown with night temperatures between 50 and 59 ºF will set flower buds regardless of day length, but growth will be slower and bud drop may occur at 50 ºF.
  • Pinching back the stems in early June to promote branching and more terminals for more flowers.
  • Pinching (also called leveling) at the end of September to remove any terminal phylloclades that are less than 1 cm (0.4 inch) long and to make all stems approximately the same length. These short and immature stem segments will not initiate flower buds until mature. After a short phylloclade is removed, a flower bud forms on the previous, more mature stem segment.

Watering & Fertilizer: Water the growing medium when it is dry to the touch. The holiday cacti are tolerant of dry, slightly under-watered conditions during the spring and summer. Do not let the soil become waterlogged, especially during the dark days of winter, but do not let the soil completely dry out either. However, following bud set in the fall, the growing medium must be kept evenly moist to prevent flower bud abscission. Never let water stand in the saucer beneath the pot.

Fertilize plants monthly from the time new growth starts in late winter or early spring, and throughout the summer using a one-half strength soluble fertilizer, such as a 20-10-20 or 20-20-20 with trace elements. Holiday cacti have a higher requirement for magnesium than many plants. Fertilize monthly during the growing season with Epsom salts (magnesium sulfate) mixed at 1 teaspoon per gallon of water, but do not apply the same week as the regular fertilizer. Stop fertilization during the late summer for greater flower bud production in the fall.

Growing Media: The holiday cacti flower best when kept somewhat pot bound. Repotting is necessary only about once every three years and is best done in the spring. The potting medium must be well-drained with good aeration, as these epiphytic cacti do not grow well in heavy, wet potting mixes. A good mix may contain 60-80% potting soil with 40-20% perlite. Choose a good brand of potting soil which is pH balanced.

A red-flowered, Thanksgiving cactus. Note the characteristic saw-toothed serrations on the stem segments.
Joey Williamson, ©2011 HGIC, Clemson Extension

Propagation

Holiday cacti are easy to propagate by cuttings, which are taken in May or June. Pinch off sections of stems with 3 to 5 phylloclades (stem segments) on each. Allow the cut ends of the sections to callus by placing them outdoors in the shade for a day or two. Choose a well-drained potting soil and new or disinfected containers for rooting. Place three cuttings at approximately one inch deep into the potting soil of a 4-inch container, or use 5 cuttings in a 6-inch container. Water the soil well, and cover the plants and rooting container with a clear plastic bag secured with a rubber band around the container. The plastic bag will act as a miniature greenhouse to keep the relative humidity at 100% to enhance rooting. Place the container in bright, indirect light until roots have formed in three to eight weeks. At this time the plastic bag can be removed, and a dilute fertilizer solution can be used at watering.

Problems

The Thanksgiving and Christmas cacti commonly drop unopened flower buds, which may be induced by an excessive number of buds or a sudden change in temperature, light or other environmental factors, such as drying out of the growing medium. Lack of flowering is often due to light interrupting the long night period (14 hours) that is required for flowering initiation to occur. Street lights, car lights, or indoor lighting can disrupt the required dark period.

The major disease is root rot, which can be prevented by avoiding excessive watering. Insects and related pests include mealybugs, soft brown scale, red spider mites, aphids and fungus gnats.

For more information, please see HGIC 2252, Common Houseplant Insects & Related Pests, and HGIC 2251, Houseplant Diseases & Disorders.

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