How to Get a Christmas Cactus to Bloom

With nights that dip into the low 40’s, the house plants that have spent the summer on our porch deck are moving inside. I only have a few plants, and I call them heirloom plants: two mother-in-law tongues from Grandma Mills, one climbing vine from Granddad Mill's funeral, one giant Christmas cactus from Grandma Murphy, and one "puppy" Christmas cactus started from that giant. The oldest of these plants is a matriarch. The big Christmas cactus from Grandma Murphy. When she left the farm and moved into an apartment in town, the cactus and the walnut stand where it perches moved to Illinois with me. Its tendrils bloomed beautifully in Grandma’s house. Bunches and bunches of pink flowers.

These are the bits of trivia I gleaned from Grandma: Give it castor oil in October and leave it root-bound. Grandma estimated that it must have been at least 125 years old. It belonged to her mother long before it moved into Grandma’s house. We did that math more than ten years ago.

In my care, I’m happy to say it stayed green and had an occasional bud in Illinois. Then, nothing. Perhaps because I didn’t believe in the castor oil tale. Or perhaps because one year I tried olive oil instead – I thought Grandma said any oil would work.

I drove this cactus and 15 other houseplants 1,600 miles to Massachusetts with Will when he was two, nine years ago. Since then it has sat stubbornly in our bedroom, braced itself through construction dust two years ago, and lived one summer on the porch deck in the shade.

Last spring, I had to do something. It didn’t look healthy. The 135-year-old limbs were wedged into the pot. Had it ever been re-potted?

I bought a pot double the size of what it was in. Then I looked at that new pot for a couple weeks. Dare I do it?  I lifted the terracotta pot out of the basket.

I was inspired.  The terracotta pot was beautiful.  In all the years I had the cactus, I had never seen this pot.  If I lost the cactus as a result of this re-potting, I still had this pot, but unfortunately, none of its history.  Had Grandma ever seen this hand-painted piece of art?

Why is the thought of re-potting more complicated than the actual job? In minutes I had dropped the root-bound old lady...

into fresh dirt and placed her on the table...

...and she still looked miserable.

Then summer happened, and she could not spew shiny new leaves fast enough! Really, really beautiful.

If she was putting all that effort into growing over the summer, I felt obliged to work out what she needed when she came inside.

Some days I don’t know where my time goes, but I know last week I spent a good hour scouring the internet trying to find the secret: “how to get a Christmas cactus to bloom.” The most concise and scientific information was from one horticulturist who gloated that if you know what you are doing, it’s really not that difficult. Light and temperature are key.

Christmas cacti rely on the light of the environment to determine when to bloom. Photoperiodism. To force blooms, and to put photoperiodism into motion, the cactus needs 12 hours of absolute darkness for 6 – 8 weeks before she will bloom. Sources give sound advice: move it into a dark closet or bathroom every night and bring it out every morning. This particular matriarch fills nearly 3 x 3 feet of cubic space. Lugging her around morning and night won’t work.

Christmas cacti rely on cool nights – ideally 50 – 55 degrees – for the same period of time that it is dark. Reading this reminded me how cold Grandma’s extra bedroom used to be. The main fall guest was this cactus.  In our house, between the baseboard heating in one zone of the first floor and the radiant heat in the other zone, temps rarely drop below 70 degrees.

Discussions were held with Bill and the Laundry Maven. Bill nor I were completely convinced we could close off a hallway for eight weeks to give this matriarch a nice dark space. Bill suggested putting her in the laundry room. The Laundry Maven bulked, saying she spends half her life in there… and now to work around this? Impossible!

The Laundry Maven’s open plan laundry room has been reduced to a walk-in & back-out galley-style laundry room. It’s like doing laundry with a happy green English sheep dog gently nudging your back side.

But allowances must be made. For 6 – 8 weeks.

Nightly at 6 p.m., I slide the hallway door to the laundry room shut in order to block the light from HRC (Her Royal Cactus).  (The Laundry Maven needs to remember to get that evening load of wash going before 6 p.m.)  I have cut, flattened, and taped two brown paper bags together trying to create a kind of blanket for her to block light from the other end of the hallway that leads to the kitchen. I need at least two more bags as this blanket only covers the top third of her. Early this morning, I saw the light from our neighbor’s back porch from the laundry room window. Can this sleeping beauty see it? Does it distract her? If only she could say… I could get a pole, lodge it between two shelves, and hang a temporary curtain.

The first night I cranked the small window wide open to give her fresh air. To make the air she breathes below 55 degrees. I closed the baseboard heater in the laundry room. When my alarm went off at 6:00, I hit a thermocline half-way down the stairs. My tired head immediately calculated adjustments to help the Malcolms and HRC acclimate to one another: crank the window shut a bit and turn the heat on in all zones. The second morning, the brisk chill was limited to the laundry room.

Where the Laundry Maven, in bare feet and summer PJ's, starts her day transferring clothes to the dryer.

Where a lovable green sheep dog – and her pup --  greet the in-direct sunlit day.

It’s Week 1, Day 5.

This grand matriarch is high-maintenance.

(Moving from my family's plants to those on the St. Maarten butterfly farm... Still Enough for a Butterfly to Land)