By Mary-Jane Pilgrim, Master Gardener
Sometimes we get questions that sound more complicated than they really are. After observing an odd occurence in my own home, I’ve been contemplating this one: “Why is my Thanksgiving Cactus blooming in March?” Sometimes, it’s a very simple answer: Because it’s not a Thanksgiving Cactus – it’s an Easter Cactus.
However, that’s not the case for MY cactus. Using the image below, I’ve correctly identified my plant as a Thanksgiving Cactus (Schlumbergera truncata) based on its leaf structure. It also bloomed profusely last fall. So what gives?
A couple of weeks ago, while watering, I noticed that some buds were forming on the window side of the plant, but not on the other side facing me. I turned the plant around. A few weeks later, it’s “bloom city” on that side, but the other side has exactly zero blooms.
I did some investigation, and it turns out that blooms require two things: cooler temperatures and long nights. These cacti are short-day plants, which means that blooms are triggered by long dark cool nights. They need for between 14-16 hours of uninterrupted darkness and 8 hours of daylight for between 3 – 6 weeks to set flower buds. Our winter seems to fit that bill — flowering that shows at Thanksgiving will often be followed by a second rush just before, at, or maybe after Easter because of the light and temperature.
Once you notice that your cactus is budding or re-budding, it’s a really good idea to leave it in exactly the same place, and to not move it. Moving the plant may result in bud drop. Also, while in flower, allow the soil to dry down somewhat between waterings.