Now is the time to trim lavender cotton

Q: Earlier this year, you wrote about some lavender cotton (Santolina) plants that were growing near a community mailbox, suggesting cutting them back and offering the plants some water every now and then. We have one that grew quite well and also several purple aster plants. All of these plants have finished blooming, and I wonder if now would be a good time to cut them down for the dormant season? — M.B.T., Albuquerque

A: As long as you are sure these guys have finished blooming, sure, go ahead and tidy them up for the coming winter months.

I would suggest that you wait just a bit longer to cut the asters back, as the spent blooms are now in seed. Finches and the like could easily enjoy the bounty the asters are providing, but that’s up to you.

I will ask that you mark your calendar and offer the stand of these hardy perennials a drink of water, perhaps monthly, during the dormant season, unless we’re blessed with precipitation.

By cutting them back now, you’ll prevent a place for litter to gather, keeping your surroundings neater, and I think that’s a good thing. You can also cut off the spent aster blooms, placing them in a paper envelope and sow them in a garden next year too. Next spring, as the weather warms, rough up a patch of soil and sprinkle the aster seeds liberally, making sure to tamp them down hard into the soil and keep the space fairly dampened. You should get asters galore that way.

So yes, go ahead and cut back these sturdy perennials now, or at least very soon, knowing everything should stay healthier in the long run.

Q: My dad had a funky Christmas cactus that lived on the coffee table in the formal living room for years and it NEVER bloomed. One year when visiting we saw it was covered with a cardboard box. When we asked dad why and he said he was tricking it into setting blooms. He’d read an article of yours teaching him what to do. He was skeptical but decided to give it a whirl. Sure enough, after following your instructions, the silly plant bloomed. Dad was just beside himself. For several years, at the end of October, we’d ask about that Christmas cactus that was now known to all of us as the “box cactus!” Well, I’ve inherited the box Christmas cactus. Dad never offered the instructions, or I didn’t listen, so will you please teach me how to trick it into blooming? The end of October is rapidly upon us! — K.L., Albuquerque

A: I remember getting an email from a reader one winter offering photos of a Christmas cactus, on a glass top coffee table, in bloom and the writer said he’d followed my suggestions. I’m not sure if it was your dad, but I’m glad the process worked for him. So here goes.

There are two ways to trigger your Christmas cactus into bloom that I know of.

First, if the plant is living in a room where you can close the curtains every night and then open them every morning, offering 12 hours of complete darkness for the next thirty days, that’s what you need to do. Close the curtains and then open the curtains during the day. If you have to go into that room at night for any reason, don’t turn on the lights but use a flashlight, getting in and out as quickly as possible. No light for twelve hours each day for thirty days.

Now if the cactus is living in a population so to speak, or you don’t have a dark room to offer, you can do what Dad did. He was taught to cover the cactus, nightly, with a cardboard box — uncovering it every morning for thirty days. If you choose this method, be sure the box is big enough to cover the plant without injuring it at all. Then after thirty days stop covering it and have the plant live as usual. Remember to hold back on the watering a bit, too. I don’t mean to allow the creature to dry out, just don’t keep it as usually tended.

Within a week or two, you should notice wee, barely pink nubbins on the leaf ends that will grow to become full-fledged flowers.

I have heard of people that place their cactus in a closet for 30 days, but to me that seems dangerous. What if you forgot to water or someone threw something on top of it without looking? No, either offer a darkroom or make the commitment to cover and uncover every day for thirty days. The reward is well worth it. Especially since you’ll be carrying on the box cactus legacy.

Good luck and Happy Diggin’ In!

Tracey Fitzgibbon is a certified nurseryman. Send garden-related questions to Digging In, Albuquerque Journal, 7777 Jefferson St. NE, Albuquerque, N.M. 87109, or to features@abqjournal.com.