Careful what you’re bringing in … and I don’t mean Halloween ghosts
![Be careful who you bring in Accidental invaders when we bring plants in from outside in the fall: (from top left): fungus gnats (inset sticky trap), millipede (inset roly poly), mice (in bottoms of large containers), cecropia moth (inset cecropia moth cocoon).](https://fwrnews.com/wp-content/uploads/Be-careful-who-you-bring-in.png)
It is fall, and Mother Nature has sure had some hot flashes and some chills. As usual, she can’t make up her mind. But before we know it, it will be time to bring in any plants that you put outside for the summer. And you might want to bring in some of those expensive “annuals” that are really tender perennials.
But what you don’t want to bring in are all the little creatures who found home in those containers during the summer when the plants were outside. Some of these animals are insignificant, some even beneficial. But just who are they and what do you do?
The first thing you should do before bringing any plant in is to do a “perimeter check.” No, do not walk around the outside of your house, but take a close inspection of the containers themselves, particularly if they are pots that have those rolled tops with a little overhang. Those are particularly convenient shelter for insects. And this happened to me.
I had a large grape ivy houseplant in one of those hanging planters with that type of edge. Back then, I never thought to check that edge, until one super cold, but sunny February morning when I woke up and thought I was still dreaming when I saw a gigantic moth on my bedroom curtain. Well, it wasn’t a dream, it was a 5”-wide magnificent male Cecropia moth drying his wings.
I couldn’t imagine where this stunning creature had come from in the dead of winter. Upon closer inspection, I saw the large 3”-long “brown paper bag” cocoon tucked right under the rim of that pot. Lesson learned. And I am glad to share that with you.
Sadly, all of the silk moths as adults are born without mouths, so they only emerge (eclose in butterfly/moth/lepidoptera terms) to look for a mate, lay eggs and die in a very short time period. My beautiful surprise February Cecropia moth didn’t even have those opportunities.
If you do find some type of cocoon/chrysalis, consider either repotting that plant or leaving the pot with the cocoon outside.
Sometimes you will find a spider’s egg case. I know, you might not like spiders or have arachnophobia, but spiders are important good people. They eat mosquitoes and all sorts of pests. Personally, when I find a spider on my houseplants, I just thank them, as they will solve most of any plant pest problems.
But you can gently roll the egg mass onto a stick and leave it outside.
Then there are the soil dwellers. These creatures are more related to shellfish than insects due to their size and living in habitats similar to insects. These are centipedes, millipedes, and everyone’s favorite, the roly-poly (aka pill bug or official name sow bug). These are soil dwellers that are nature’s garbage eaters. They are part of the decomposers.
Often people will call me and tell me that these are killing their plants because, they rationalize, that they have a declining plant, and when they go to investigate and pull the plant up, there can be any of these three — centipedes, millipedes and roly-polys in the bottom of the container.
They are the hearse, not the ambulance. Your plant was in decline already, and they came to eat the dying roots; they do not cause decline. You have also created their dream home habitat: moist dark, easy to come and go.
These insect kin do not need to be controlled, as they tend to dry up in our warm, dry houses within a week after coming in. Again, beneficial to plants, they will just decompose adding nutrients to your containers.
If you find some wanderers, or if you find these in your basement or windows of window wells, know that they do not reproduce in the home, they do not eat anything of value, so you can either scoop them up and pitch them back outside or you can squish them. No need to start spraying pesticides inside the home.
Now on to the Trojan horse story. Sometimes, particularly when bringing in big pots, you might also be bringing Mickey and Minnie Mouse in. Those large pots with those large drainage holes can make nice summer cottages for mice. I always put a big dry cleaner bag around my pots outside for about a week before I bring them in.
Typically if a mouse is taking up housekeeping in your pot, they will come out into the bag and run off. A preventive for this is to purchase some hardware cloth (a smaller gauged hole wire mesh that you can find in the chicken wire area of the big box stores). Before you pot up those big pots in the spring, line the pot (and push right up against the drainage holes) with hardware cloth and then fill. Mice won’t be able to go through those strong wire tiny squares.
And then finally, the bug that causes most problems for people who have plants indoors. This can be houseplants, spring grown seedlings, fall plants brought it, or even a new plant you just purchased. (Just had a call on this yesterday about the latter.)
Fungus gnats. Less important and dangerous to the plants than they are immensely frustrating and irritating to us. Fungus gnat adults are tiny brown/black mosquito looking insects. They are completely harmless. The adults barely eat anything and will not harm your houseplants or seedlings. But they can get numerous fast.
Fungus gnats lay eggs in the soil of moist media (potting mix). The larvae of fungus gnats feed on the decomposing part of the media, fungi, and algae in the soil. But if they run out of that, they can start to feed on live roots of seedlings.
So what to do? Fungus gnats come from overwatering or an overly moist environment. First solution is to reduce watering. Some people find additional success by putting a thin layer of sand on the tops of their plant’s soil surface to keep that area drier.
You can also use yellow sticky traps to trap the adults. Or you can live with them. They tend to pass as the houseplants get drier in our heated homes.