Fairbanks Weather 12/26/11

It’s the last Monday of the year, and the first after the solstice. The days are getting longer! Today was almost a minute and a half longer than yesterday. The sun will rise at 10:59 this morning and set at 2:44 this afternoon for 3 hrs 45 minutes of theoretical sunlight, and the sun will reach 2.1° above the horizon. The coldest part of the year is still before us, but at least we’re getting some light back. By this time next week, the days will be more than four hours long.

This morning about noon. Photo to right was yesterday.

We’ve had some snow over the last week, and the snowstake has finally come unstuck. It has some snow frozen on the near side which makes it difficult to read, but I think from the base of the triangle of stuck snow it read about 13” depth when it got too dark to see last night. We had snow (as well as fog) Christmas day, but only about a tenth of an inch was expected. From the way it was snowing around 6 pm, I suspect we got more than that. (8:30 am: we had more than a tenth of an inch, but it’s still too dark to tell how much more. Roads were very slippery and visibility terrible last night. 11:30: Left photo suggests we had about an inch last night.) Temperatures? Below zero even at the warmest, and around 20 to 30 below at night. We don’t really have much warming in daytime, though.

I think I see the first, faint beginnings of buds on the Christmas cactus, after only a little over two weeks of a twelve on-twelve off light cycle. And there is no question about the sunquat, a citrus hybrid. Hope its blossoms smell better than the worm tea I treated all the plants to yesterday!

Nightlength Sensitivity in Houseplants

I think I’m going to have to reset my plant lights if I want my Christmas cactus to bloom.

One of the plants I ordered from Logee’s last fall was a Christmas cactus, “Christmas Flame,” with beautiful peach-gold flowers – at least, according to the catalog picture. It’s healthy, glossy, and generally looks as if it really enjoys my cool plant room, but there’s not the slightest sign of buds. And I’m afraid I know why.

Christmas cactus are day-length – or more accurately, night-length — sensitive. They need cool temperatures and at least 12 hours a day of uninterrupted darkness to form buds. Cool is fine; my plant room is thermostatted to 65° daytime and 55° nighttime temperatures. Night length? Well, I’ve had the lights programmed to be on 16 hours a day, to make up for the fact that at this time of year the plants are almost totally dependent on artificial light. Cool temperatures alone are enough for some cultivars, but apparently not for this one.

So I’ve reset the light cycle so the lights go on at 8 am and go off at 8 pm. I’ll have to keep the door to the plant room closed in the evening, and I may have to move the plant away from the window for the next full moon. (Not this one; we’re predicted to have cloudy skies for the next few days.) I don’t think the snow reflects enough light from my bedroom window to be a problem, and the nearest street light is at least a tenth of a mile away and not on the same side of the house as the plant room. Aurora? Not likely to be bright enough to cause a problem.

Supposedly it takes 6-8 weeks of long nights to get the buds going, so it’s likely to be February before I know if my cactus is going to bloom. Meanwhile the jasmine has put out a flower, the first narcissus opened today (and I can actually smell it) and the potted rose bush is putting out a new flush of growth. It may be winter outdoors, but the lights and the plants are going great indoors.