Christmas Cactus  General
I always thought of myself as fairly knowledgeable about many plants and the Christmas Cactus was no different. At least that was until I started researching support material for this article. This was when I realized how much more I needed to learn and just how much difference of opinion existed between the so-called "experts". In fact, the difference is so great that the opinions take almost "polar extremes" on many issues. In fact, many experts go so far as to not be able to agree with the names of some species and subspecies or "cultivars" are often used in place of the true Latin name for the plant. Couple this with the fact that so much cross hybridization has occurred and the lines become very much blurred as to which species is which. The good news is that all of the species of holiday cactus require pretty much the same care and the primary difference is in the time that the plant blooms naturally. All holiday cactus (Thanksgiving, Christmas and Easter) are "epiphytes" from the mountainous regions of South America and are members of the cactus family. This means that they live in the trees of the South American rain forest areas in the crotches of trees and have the ability to store at least some water water. Holiday cacti sold from Thanksgiving through Christmas are cultivars of the Schlumbergera cactus family while the Easter cactus is of the species Hatiora gaertneri. Often, you will see these marketed as "Zygocactus", which is an old classification for the plants that many growers have been slow to change but many plant lovers still recognize. Holiday Cactus blooms in a color range from reds, pink, purple, orange, whites, creams and yellows and normally bloom during the winter months in the wild when temperatures are lower and the day length shortens. It is temperature and day length that normally triggers the process to bloom. This same trait will cause your cactus to bloom naturally, but not necessarily at the appropriate holiday. The easiest way for the lay gardener to tell the two genus apart is in the leaves and blooms. However, differentiating individual genus may prove much more difficult. Members of the Schlumbergera family (the Thanksgiving and Christmas Cactus) have spiny (not sharp) edges along the leaves, while members of the Hatiora gaertneri (Easter Cactus) family have smooth edges (see figures 2 and three below). However, recent hybridizations have made this trait somewhat less pronounced in many species. The other obvious way is in the blooms. Members of the Schlumbergera family have petals that curve upward and back, while members of the Hatiora gaertneri family have petals that open wide and flat, much like a true cactus bloom. Additionally, Easter Cactus bloom much later naturally than either Thanksgiving or Christmas Cactus, normally around the Easter season. Holiday cacti can be a very long lived plant with specimens of 20 - 30 years being not uncommon and can reach 8 to 10 feet across with proper care and not cut back regularly.Light Light shade to dappled sun in the summer (if moved outside) and bright light indoors. Plants will do well in an east window during the winter or with diffused light from a west or south window (as through sheers). Never allow your cactus to sit in direct sun during the warm months. Temperature Holiday cacti are native to cooler, high altitude regions of South America. Therefore, they will not tolerate high temperatures for very long and may require some additional shading or cooling in very hot regions or times of the year. The ideal temperature for holiday cacti are: Active growing period - 70 - 80 degrees F during the day and 60 - 70 degrees F at night. Rest period - 50 - 60 degrees F during the day and 50 - 55 degrees F at night. Bloom set period - 60 - 65 degrees F during the day and 50 - 60 degrees F at night. Blooming period - 60 - 70 degrees F during the day and 55 - 60 degrees F at night.Rooting cuttings - 70 - 75 degrees F constant Water Contrary to their name, holiday cacti do not like to be dry. However, over watering is the leading cause of plant deaths since the roots tend to rot easily. It is better to err on the dry side than to much water. One of the biggest keys to watering success is having a soil that drains well and not allowing the pot to sit in water. Also, do not give the plant small doses of water, but rather water until the soil is completely wet and then allow to drain thoroughly. A guide to watering is as follows: Active growth period - water when the surface feels dry on the surface. Rest period - allow the soil to dry just until it starts to pull away from the pot. But never allow your cactus to shrivel (it will recover from this when watered). Somewhat limp is ok but no more. Bloom period - restrict water, but only until the soil feels dry to about 1/4 inch down in the soil. The soil should be somewhat dryer than during the active growing period but withholding to much water will decrease the number of blooms. Blooming period - Watering should be somewhere between the active growing period and bloom set. Allow the soil to dry slightly between watering. Rooting cuttings - keep the medium constantly moist to the touch. Fertilizer and Feeding Holiday cactus are not heavy feeders and have evolved to having a limited supply of nutrients. However, this does not mean that they do not require periodic feeding. For best results provide a balanced liquid houseplant fertilizer  with micronutrients at 1/4 strength every other watering during the growing season. Diluted compost and manure tea would also be good choices. fish emulsion is an excellent choice, but should not be used indoors because of the smell. Granular, slow-release fertilizers probably would not be good choices as these need to be worked into the soil and holiday cactus do like to have their roots disturbed. Do not feed your holiday cactus during the blooming or rest periods. Proper soil acidity crucial to good plant growth. Holiday cacti need a soil pH of 5.5 to 6.2 to do well. and and should be checked often. If the pH is allowed to fall below 5.5 the plants will start to take up excessive amounts of iron and manganese which will lead to serious plant damage. The easiest way to check this is with a test meter or litmus paper. This is necessary because the tap water in many areas is alkaline and watering will leach the acid from the soil. The best ways to acidify the soil of your holiday cactus is by one of the following methods (in order of effectiveness): Nitric Acid - 1 to 2 drops per gallon of water depending on how much remediation is needed. Use this with extreme caution and keep well away from children in its original container. The diluted water will cause no harm. Cider Vinegar - 1 teaspoon per gallon of water as needed. Stale Tea - Water with stale tea (dilute if needed per your test results) with every second or third watering. Adding additional Potassium will help to bring out stronger colors in the blooms and increase the overall number of blooms per segment. Soil Soils that are high in organic matter but have excellent drainage are what these plants need. A good mix would be a high quality potting mix with equal parts of course leaf mold or course compost, sand and 1/2 part perlite in equal proportions. If you tend to over water consider using a commercial potting soil designed for cactus and add and equal part of course leaf mold or course compost. As holiday cacti tend to have very large and heavy top growth in proportion to their roots, sand and aquarium gravel are the preferred materials to keep the soil loose. Potting Holiday Cacti do not care to be disturbed and need infrequent repotting. Many very fine specimens go without repotting for years and the plants bloom best if left somewhat pot bound. Each year, when you bring your plants out of their rest period and when you are ready to move outdoors, gently knock the plant out of its pot and check the root ball. Repot only when the roots start to become matted. To repot, choose a pot that is roughly 2 inches larger than it was originally growing and make sure to add proper drainage to the bottom of the pot. Make sure to detangle the roots and loosen them before repotting. Keep the plant in a shady area for 1 to 2 weeks or until new growth starts. As holiday cactus must have good drainage, clay pots are an excellent choice for holiday cacti. If you choose to use plastic or glazed pots, consider adding some additional sand or perlite to your mix. Blooming All holiday cacti bloom when the nights grow longer and night temperatures grow cooler in nature. But not all of the cultivars bloom at the time you may wish them to. Many growers will rely on different species in order to provide them with blooms at the time they wish, while others just allow their plants to flower naturally (as they will, given proper temperatures) at the time the plant chooses. These bloom times (for Thanksgiving and Christmas cacti) will range anywhere from early November through January, depending on the cultivar. The plants you see so beautifully displayed in the stores are normally "forced" into blooming at a particular time, as are Poinsettias. The odds are that the plants you see blooming in your store at the end of November and through December are more than likely cultivars that are bred to bloom near that time anyway and the forcing is more to guaranty bloom at a particular time than to force it to bloom at an unusual time for the plant. But this can not be guaranteed. I personally prefer to start giving them cool (50 to 55 degree if possible) temperatures at night and warmer days (60 - 70 degrees) for 2 to 3 weeks stating the end of September and then let them bloom when they want to naturally. However, if you are the adventurous sort and wish to try your hand at forcing them to bloom at Christmas (or possible Thanksgiving) here are the basics of forcing your holiday cacti. Bear in mind that this is based on not knowing the cultivar and its normal blooming pattern so we are assuming that they are a cultivar that blooms around December or January naturally. - Beginning around the first of September, bring your plants indoors and place them under artificial grow lights for 14 to 15 hours per day and keep them watered as you would outdoors (remember the amount of water needed indoors will be less). Also keep the plants at around 70 - 80 degrees F. This will simulate the long days of summer and keep the plants actively growing.
- Around the last week of September or first week of October, reduce the hours of bright daylight to 9 hours and reduce the watering to allow the top 1/4 to 1/3 inch of soil to dry between watering. Reduce the daytime temperature to 60 to 65 degrees F. Each night place the plants in a totally dark location (as with Poinsettias) and at a temperature of 50 to 55 degrees F for 13 hours. the dark period should not be interrupted, however, this is not quite as critical as with Poinsettias. Set a schedule for this and keep it constant as with your Poinsettias for 2 to 3 weeks (I like to do Poinsettias and Holiday cactus together at the same time when I do this).
- At the end of this period the plants should have started to set blooms (these will first appear as small round buttons on the ends of the segments). When this occurs, discontinue the cool/dark period and place in a location of 65 to 70 degrees F daytime temperature and 60 to 65 degrees F at night in bright light (such as an east window) and provide additional water, but still somewhat dryer than during the growing season. The first blooms should open approximately 4 weeks afterward (depending on cultivar).
- To hold back the blooming period by a week or two, keep them in the cool and long night period another week or two. Be aware that to much cool time may bring out red tones in some white varieties.
Some things to avoid during bloom: - Keep your blooming holiday cacti away from drafts, heat vents etc.
- Keep out of direct sun (except 1 or 2 hours of early morning sun from an east window).
- Temperatures in excess of 70 degrees F may cause bloom drop.
- Over watering - keep somewhat dryer than normal.
- Don't feed your plants during bloom.
- Rough handling and jostling of the plant may cause bloom drop (especially Easter cactus). If you move your plants to a cool room at night (recommended), try keeping them on a roll around cart (like a tea cart) to display them and to avoid handling the plant any more than necessary.
PropagationHoliday cacti are among the easiest plants to propagate and require little in the way of special requirements. The normal time to propagate these is between December to March, just before the plants a placed into a rest period. But they can be safely and successfully propagated any time (it's a great way to save a broken branch). To propagate your plant simply twist (do not cut) off single mature sections from the growing tips (normally only the first 1 or 2 mature sections are used, however try rooting all that break off). Stick the base end into a mixture of sand and peat moss and keep the cuttings damp continuously. Place your cuttings in a shady location away from any sunlight for approximately 3 - 4 weeks. This is really all that is needed. However, I have found the following works better for me and gives me a better yield. Fill a pot of about 6 to 8 inches diameter with a mixture of equal parts of peat moss, sand and perlite. In this I stick 8 - 10, single segment cuttings 1/2 way into the mix. I then make a hoop (like a 3-legged halo) out of metal coat hangers and push this into the top of the pot so that the ring is about 3 - 4 inches above the cuttings. I then mist all of this very well to settle the mix around the cuttings and slide all of this into a clear plastic bag to which I have punched 12 - 15 holes around the top with a paper punch (for ventilation) and tie it shut. I then place this rooting container in bright light or an artificial light garden, on a heat mat at 70 to 75 degrees F until new growth begins. If you plan on starting more plants than this, try using those seed starting trays with the clear plastic domes and the "cell packs" that go in them for ease of handling later. Once new growth begins, the cuttings should be rooted and can be planted into individual 3 inch pots. Keep the plants out of bright light for a week or so and keep them at about 65 to 70 degrees if possible. Plants will develop a new segment about once every 6 weeks under ideal conditions. To promote multiple shoots, twist off the new segments when they reach approximately 1/2" long. Thumbnail schedule for Christmas cacti: The schedule of the ideal life of a Christmas Cactus January - Flowering. Water normally. Temperature no less than 55 degrees F. February to March - Resting (55 degrees, infrequent watering). April to May - Water thoroughly when potting mix begins to dry out. Place in bright light and June to August - Place outdoors in a shady spot. September to October - Plant prepares to flower. Reduce length daylight hours. Keep on the dry side and cool (55 to 60 degrees F) until flower buds form. Then increase water and temperature. November to December - Flowering. Water normally. Temperature no less than 55 degrees F. Back To Top | 
