Well, I'm going to change my statement. Spider plants are, hands down, the BEST plants to have in the home. In case you're wondering, they look like this. Why am I saying they're the best? Well, for one thing they're one of the best overall air cleaners when it comes to toxins. Indoor air can often be more toxic than outdoor air, so having plants to clean the air is not a small matter.
This is especially important in Alaska since we spend so much of the year cooped up in our homes. Not only are we breathing in all those toxins, but in efforts to keep all that precious, expensive heat indoors there can be major problems with getting enough ventilation. (My friend J is an engineer who works specifically on ventilation problems a lot of the time so I get to hear about this quite a bit.) We need the oxygen that plants provide because buildups of carbon dioxide and other harmful gases are distinct possibilities. The general rule of thumb I've heard is that you should have about 1 plant per hundred square feet of living space. But even having one plant will improve your air quality and, thus, your health.
Speaking of Alaska, the lack of daylight is a concern for most houseplants in the winter here. Mint, an incorrigible, invasive weed elsewhere, died in my kitchen because of the lack of light. But spider plants? Hell no. To say that they're shade-tolerant seems to me to be rather an understatement, and therefore a disservice to the plants. As long as they get more than about two minutes of vague, shady, North-facing light, they seem to do fine.
If you're worried about pets eating plants (especially cats--they seem to be the most persistent chewers) spider plants aren't toxic to pets. It's never good for a pet to eat too much plant matter because it can upset their stomachs, but at least this plant won't kill your pet. I finally brought one home from work the other day and when I woke up the next morning, my cat was happily munching away at the leaves. The only reason I took it away from him was because I'd like to have this plant in my house for more than 24 hours before
The biggest reason I recommend spider plants is because they're just so darn hard to kill. Seriously. I'm quite certain I've over-watered mine, but they just accept the extra water and keep going. When we have to leave the plants at work over breaks, such as Christmas, the spider plants are always the ones that look the best and healthiest, despite the lack of water and light. I hate to say it this way (ok, not really) but even my boss can keep alive the spider plant in her office. That's saying something.
They also propagate so easily. This might not be a real selling point, but it's something to factor in. If you know someone with a spider plant, don't bother buying one. Just ask them for a shoot. Then you can pot it and soon you'll have your own crazy-big plant. After a while you'll notice the plant putting out little shoots, like baby plants. (See all those little ones hanging off the edge?) Really, it's seeking to spread. You can either trim that section off and compost it, or if you want more plants (either for yourself or to give away) just snip it off near the new base and put it in some water. It will grow roots quickly (after all, it's meant to be a whole new plant) and then it can be planted. I've never dealt with an easier plant. One of my "baby" plants was putting out its own "babies" less than a week after I first planted it. If your first shoot doesn't work, whatevs. The main plant will put out more babies so you can try again. In fact, one of my plants at work currently has about six offshoots hoping to find dirt to grow in.
They're easy to control, size-wise. If all you want is a small plant, keep it in a small pot. Other than the off-shoots it puts off, you shouldn't need to do any trimming. However, if you want it to get big and lush and take over a corner of your house, just put it in a bigger pot. It will fill whatever size pot you put it in and be happy.
In terms of looks, I'll admit that they're not the most beautiful plants. They don't put out flowers, they don't have peculiar leaf shapes, they don't fruit or really do anything special. But this seems to be a personal thing. My coworker mentioned just the other day that she loves their green, draped foliage. And for me, the ease of their maintenance and what they do for the air quality more than make up for a lackluster appearance. Put them with a couple of other plants and you'll never notice a lack of beauty. I have mine in a corner with my vine and its heart-shaped leaves, a broad-leaved plant that I don't know the name of, and one of my Christmas cacti. They balance each other out since they're all so different.
The first two plants I got at work were given to me by Shane, back when he worked at the greenhouse on campus as a student. They were "too ugly" for the crew to bother planting outside, due to mistreatment. If he hadn't given them to me they were just going to be thrown out. Well, they're kind of like the ugly ducklings that turned into swans. They're large, they're as beautiful as spider plants get. They're healthy. And from them, I've made several more plants, including one that I'm going to give to my friend L (a perpetual plant killer). Not bad for some freebies.
In case you're wondering what my second pick would be for one plant in your home, it's aloe, for all of the reasons mentioned above. Also, and I don't know why since they're really similar, but I think aloes are much prettier. Weird, I know. Sadly, I don't actually have an aloe plant! A situation I plan to correct soon. I used to have a cutting (or rather, the part one of the dogs knocked off) from one of my mom's, but couldn't figure out a good way to transport it from Seattle to Fairbanks. So I'll just have to buy my own.
**Updated: I didn't think of this before, but the ASPCA lists aloe vera plants as being toxic to cats. Since my cat does love to chew on plants, particularly ones with elongated leaves such as aloes possess, once I do get one I will have to keep it out of reach of my cat. It will most likely go in a hanging basket. I tend to keep plants that are not toxic which my kitty likes to chew on in the winter (such as chives) in a place easily accessible by him. In the summer this isn't a problem since we let him roam outside and he happily eats grass.