Rootlike Growths On Christmas Cactus: Why Christmas Cactus Has Aerial Roots
By: Mary H. Dyer, Credentialed Garden Writer
Christmas cactus is a striking plant with bright pink or red blooms that add some festive color around the winter holidays. Unlike typical desert cactus, Christmas cactus is a tropical plant that grows in the Brazilian rainforest. The cactus is easy to grow and a cinch to propagate, but Christmas cactus has some unusual attributes that may cause you to wonder what’s going on with your plant. Let’s learn more about roots growing from Christmas cactus plants.
Why Christmas Cactus Has Aerial Roots
If you notice root-like growths on Christmas cactus, don’t be overly concerned. Christmas cactus is an epiphytic plant that grows on trees or rocks in its natural habitat. The roots growing from Christmas cactus are actually aerial roots that help the plant cling to its host.
The plant is not a parasite because it doesn’t depend on the tree for food and water. This is where the roots come in handy. Christmas cactus aerial roots help the plant reach sunlight and absorb necessary moisture and nutrients from leaves, humus, and other plant debris that surround the plant.
These natural survival mechanisms can give you clues as to why your potted Christmas cactus is developing aerial roots. For example, low light can cause the plant to send out aerial roots in an attempt to absorb more sunlight. If this is the case, moving the plant into brighter sunlight may diminish the growth of aerial roots.
Similarly, the plant may develop aerial roots because it is reaching out to find more water or nutrients. Water the plant deeply whenever the top 1 to 2 inches (2.5 to 5 cm.) of potting soil feels dry to the touch. Water sparingly during fall and winter, providing just enough moisture to keep the plant from wilting.
Feed the plant once every month, beginning in late winter or early spring, using a regular houseplant fertilizer. Stop fertilizing in October when the plant is preparing to bloom.
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Read more about Christmas Cactus
Do Christmas cactus like to be rootbound?
QUESTION: Do Christmas cactus like to be rootbound? Someone told me not to repot it because it’s healthy right now. – Forrest D
ANSWER: Christmas cactus grows well with crowded roots, so your friend isn’t totally wrong. Christmas cactus can do ok when it has become rootbound, but you should still repot your holiday cacti every four years, increasing the size of the pot by two inches each time you repot.
Repotting a Christmas cactus can be a challenging operation, as you can easily hurt the plant trying to remove it from its pot when it has become rootbound. The easiest way to get it out without hurting the plant is to break the pot. Clay pots are cheap, so it’s not a big loss, and it makes it much easier to rehome your cactus without damaging it.
Signs that your cactus has become root bound include noticing the soil in your planter growing increasingly hard, seeing the roots growing out of the drainage hole/holes of your pots, or if the stems of your Christmas cactus start to turn yellow or brown (the latter symptom is also sometimes a sign of overwatering, not overcrowding). If you notice these signs, it’s okay to keep your plant in its overcrowded pot for a few more weeks, even months, as it really does enjoy being crowded. But eventually, you will want to repot to give it some more room, and to bring your cactus some newer, more fertile soil in the process.
Use a potting soil that is specially formulated for cactuses and succulents to increase water drainage speed. Put enough new soil in the new, larger replacement planter, so that the top of the root ball will sit approximately one inch deep from the top of the pot. Gently brush off the root ball and remove a good amount of the old soil from the roots and root ball. You may want to moisten or rinse the roots off with water to get the majority of the oil soil off of the roots and root ball.
Next, put your cactus into its new pot and carefully fill in the area around the root ball with the fresh new potting soil that was formulated for desert plants. Remove any yellowing or dried up stems that you notice while repotting. Once the new soil is firmly in place, water your Christmas Cactus deeply and select a shady area to place it in for a few days while it gets adjusted to its new home, new soil, and extra space.
Keep your cacti in a shady spot on the porch or patio during the spring and summer, where they can get lots of fresh air and indirect sunlight. Take a few cuttings every year in the fall if you like, and give them away as gifts once they mature. In the fall, bring them inside and keep them in a dry, darker location away from direct sun. If you can provide a slightly humid indoor environment, your Christmas cacti will do especially well.
When October rolls around, start drying the soil to encourage holiday blooming. In lue of watering once per week, cut down to just providing a light drink once every three weeks. Darkness and dryness are both essential to encouraging holiday blooms. Some gardeners even provide covers, keeping their cacti in the dark for a few weeks in order to encourage their Christmas cacti to flower.
Schlumbergera cactus has a number of features that distinguish it from other members of the family. These include:
- Winter bloom, when most indoor plants rest.
- It can grow even on windows facing the north side, easily tolerates a lack of lighting.
- In summer, it needs fresh air, it feels great on a shaded balcony or loggia.
- Loves a warm shower very much.
- At home, lives up to 20 years.
- During budding, the plant should not be turned over or rearranged so that unopened buds do not fall off.
- It can be grown in the usual and ampelous way.
The most important thing a Christmas Cactus not blooming needs is darkness for more than 12-hours each night. Light should begin to be restricted at the end of September.
Maintain moderately cool temperatures during the day and night, ensuring the plant never gets direct sunlight and adequate watering with fertilizer restricted to only from spring through to summer, and you should see your plant producing buds at the leaf tips within 8-weeks of restricting light.
Once you see the plant producing buds, take care with watering to make sure it doesn’t drop the ones it produces.
The buds will gradually enlarge then bloom within 8-to-12-weeks of the buds producing. Start prepping your Christmas Cactus in late September and you should find it’s in full-bloom just in time for the festive season.
Best container for rooting Cuttings
I put a few stones in a glass jar, this is a recycled salad dressing jar I was practicing my glass painting on, the stones are about 2 inches deep.
Before I put any water or my cutting in the jar I write what color of cactus it is on one of the sections, I have several and I usually decide to root more than one at a time.
I add water to the jar before placing my cutting in it.
You want the water to barely come to the top of the stones. The cutting is only slightly touching the water, it is resting on the top stones.