Plants in my Apartment – Christmas (Holiday) cactus

Thanksgiving Cactus in Pot

This week’s plant is the Christmas cactus. The plants we think of when we hear Christmas cacti are actually three different species of cacti, the Christmas cactus, Thanksgiving cactus, and Easter cactus, known collectively as holiday cacti. Holiday cacti are native to the forests of South America and were brought to Spain by returning explorers more than 300 years ago.

In their native habitat the holiday cacti are epiphytes, like air plants. While they grow on trees they are not parasitic; they draw their nutrients from decaying organic matter that they find on the tree instead of the tree itself. Interestingly Holiday cacti do not have true leaves. What we think of as their leaves are actually stem segments called cladodes.

Holiday Cactus leaves
Source: http://www.extension.iastate.edu/publications/rg308.pdf

A true Christmas cactus (Schumbergera bridgesii) typically blooms from late December to March. Their leaves do not have quite the pointy projections that the Thanksgiving cactus does, but are not as rounded as the Easter cactus. Their flowers are a red-ish color.

The Thanksgiving cactus (Schlumbergera truncata) is what people are typically referring to when they are speaking about a Christmas cactus. It is the most widely grown species. Its blooms can be a range of colors (from white to red to lavender to orange and many shades in between) and typically appear from late November to late December. The Thanksgiving cactus has distinct projections from the side of its stem. The picture at the top of this page is a Thanksgiving cactus, as that is the species I have in my apartment.

In an entirely different genus than the Christmas cactus and the Thanksgiving cactus is the Easter cactus (Rhipsalidopsis gaertnerii). The Easter cactus typically blooms from March through May and has pink or red flowers. It has been known to bloom again in fall. The Easter cactus has rounded scalloped edges to its stem segments in contrast to the Christmas and Thanksgiving cacti.

Growing Information

Fortunately all holiday cacti have similar growing conditions. The only difference among them is the amount of light required to set flowers. They are typically very easy to care for and can live for a very long time, up to several decades. The following requirements apply to all the holiday cacti.

Size: Holiday cacti branches can grow up to 3 ft (91 cm) long if not pruned. The flowers measure 1-3 in (2.5- 7.5 cm) in length.

Water Requirements: Holiday cacti are happiest when their soil is kept evenly moist. Being from a tropical environment, they are not as tolerant of drought as other cacti.

Light Requirements: The holiday cacti prefer light shade. Light that is too intense can burn the plants.

Soil Requirements: The Holiday cacti like well–drained soil.

Temperature Requirements: Holiday cacti do not like temperature extremes or drafty locations. They prefer temperatures between 55-75°F (12-24°C).

Nutrient Requirements: It is recommended to fertilize with a high-potassium fertilizer once every 2 weeks after flower buds form. Otherwise a typical houseplant fertilizer is fine.

Pruning: A good time to prune your cacti is after it is done blooming. This will encourage the plant to branch. The cuttings can then be used to start new holiday cacti. Directions here.

Pests: Holiday cacti have few disease or insect problems. They can occasionally develop root rot or be plagued by mealy bugs or spider mites.

How to make them bloom:

Both the Thanksgiving and Christmas cacti are short-day plants, requiring a shorter day-length and cool temperatures in order to set flowers. They require at least 12 hours of uninterrupted darkness . According to the Iowa State Handout :

“To ensure that the plants bloom around Thanksgiving or Christmas, place them in a spare bedroom or basement where no artificial lights are used at night. The plants should receive bright light during the day and the temperature should be kept cool, under 65°F.”

Easter cacti are day-neutral plants and will bloom with the amount of light normally available at that time of year.

Once you see flower buds on any holiday cacti, make sure to protect them from drafts and keep the soil moist to prevent those buds from falling off.

Sources

San Diego Natural History Museum –  General information about the Christmas cactus and its history.

Reiman Gardens @ Iowa State University Growing Holiday Cacti Handout – Discusses the different types of holiday cacti and how to care for them.

Purdue Extension Christmas Cactus FAQs – General Care instructions for Christmas Cacti.

Organic Gardening Tips for Christmas Cactus Care – Growing guide and care instructions

Clemson Cooperative Extension – Detailed information about Thanksgiving and Christmas Cacti.

University of Connecticut Home and Garden Education Center – Detailed information about Holiday Cacti.

Plants in my Apartment – Grafted Cactus

As far as I remember (which is not very far at the moment) my first houseplants were cacti. As a child I was fascinated by their odd shapes, colors, and spines. Unfortunately I didn’t understand that their water requirements were a bit different than the normal houseplant, and in my zeal for taking care of them I overwatered and killed them. I moved away from them as plants towards ones I had a bit more success taking care of, namely African violets. Until this past May I hadn’t had a cactus since I was a child. May was when this little guy came into my life.

OLYMPUS DIGITAL CAMERA

My little sister called me one day and told me that, in the end of year rush to move out and get rid of things, someone had planted a cactus in the community garden, and asked if I wanted it. While some cacti do well in South Florida, this one was clearly meant to be an indoor plant. Even though I didn’t know what type of cactus it was I decided what the heck, and said I’d take it. She brought me this cute little grafted cactus, which I repotted it in a broken mug. It had been living happily (I hope) in my window ever since.

Grafted Cacti are commonly found in grocery stores and home improvement stores, and are popular as houseplants. While most people think that the colorful top is a flower, it’s actually a different type of cactus than the bottom portion. The top portion is Gymnocalycium mihanovichii friedrichii, or as it is commonly know, a moon cactus. This variety of cactus comes in a range of bright eye-catching colors, but does not produce chlorophyll so it cannot make its own food like a normal plant. The moon cacti cannot live for more than a few weeks by themselves, so they are grafted onto a different species of cactus, which has chlorophyll, so it can survive.

In order to graft cacti together, the tops of both cacti are cut off with a sharp knife. The desired top is placed on the desired bottom and held together by rubber bands until the junction has healed. More detailed instructions for how to graft cacti can be found here. Grafting is a technique also used in fruit and flower propagation.

As young me found out, caring for a grafted cactus is a bit different than caring for other houseplants. The most noticeable difference is the water requirements, but there are other differences as well.

Growing Information

Water Requirements: The general rule of thumb that I’ve come across over and over again with regards to cacti is “When you water, water well”. It is important to let cacti dry out between waterings or you risk drowning it.

Soil Requirements: Grafted cacti grow well in any succulent mix, high quality planter mix, or humus.

Light Requirements:  Light shade is the perfect amount of light for grafted cacti.

Temperature Requirements: Grafted cacti should be kept in a room that is above 60°F (15°C). Temperatures over 100°F (38°C) can also be damaging to cacti.

Nutrient Requirements: It is a good idea to fertilize your grafted cactus monthly between April and September (growing season). Standard houseplant fertilizer that has been diluted can be used, but take care not to over fertilize the cactus or it may lose its shape.

Pruning: If any side branches grow from the green base, cut them off as they are trying to bypass the moon cactus on top. There is no need to cut off the side branches from the moon cactus.

Grafted cacti typically only live a few years, don’t take up a lot of space, and don’t require a lot of care making them great for anyone who wants a houseplant without the hassle that larger, more involved plants can bring. Because they do not typically grow any larger than they are when you bring them home, grafted cacti are also great plants for small spaces like apartments and dorm rooms, but their texture, color, and personality make them great additions to any houseplant collection.

Such a pensive cactus...
Such a pensive little cactus…

Sources

Cactus Collection: Grafted Cacti – Information about the moon cactus, the base cactus varieties, and the grafted cacti.

Cactus Collection: General Care – General care instructions for cacti.

SFGate Red Top Cactus Care – General care instructions for Grafted cacti.

UCC’s biology department plant of the week: Grafted Cacti – Good general information and instructions on how to graft cacti.