Most of us have that one friend or family member who reliably texts you with life updates, posts Instagram Stories about her commute to work, and generally goes out of her way to keep you informed. And then there's the friend who's a bit more private about her feelings. You can usually recognize the signs when something's bothering her, but she makes you guess to figure out what the problem is. Your houseplants are like this second type of friend.
The signs that something is wrong are typically pretty obvious, even to inexperienced growers—leaves turning brown, leaves falling off, wilting, not producing flowers—but figuring out what's causing it can take a bit of sleuthing. If you're struggling to keep your houseplants alive, here are a couple of things black thumbs should know that will make the diagnosis a bit easier. And, much like your relationship with your favorite introvert, the best approach sometimes requires backing off a little bit, and letting them have their space and solitude.
1. Too much water can be just as bad as no water
Plants are not like dogs. You can't just give them a bowl of water, top it up daily, and expect them to drink when they're thirsty. If you water your plant daily "just in case" you will likely kill it in a matter of weeks. Plants absorb oxygen in the soil through their roots. When you give your plants too much water, the soil becomes waterlogged, meaning the tiny air pockets in the soil that plants use to breathe are all filled up with water. Plants living in waterlogged soil will eventually suffocate, or at least fail to thrive. Signs of overwatering might include leaves turning brown (and that means most or all of the leaves, not just one or two, which is normal), roots growing near the surface of the pot, and mold or other fungal infections.
How to fix it: Stick the tip of your finger into the soil down to your first knuckle (or use one of these digital soil testers). If the soil is dry, water it. If it's damp, let it alone for a few days. For most houseplants, watering once or twice a week on a set schedule should do the trick.
2. Light really does matter
I think a lot of us tend to be overly optimistic about how much light a houseplant really needs. You read "tolerates low light" on the tag and think, "perfect, this will look nice in my windowless bathroom." What "tolerates low light" really means is that your plant will hang on to life in dark places, but fail to thrive as the show stopping, Pinterest-worthy decor piece you hoped it would become. I had this experience with a peace lily that lived on top of my dresser for a few years. It was perpetually on death's doorstep until I gave it a new home in my office window and watched it perk right up in a matter of weeks. Sometimes this can be a hard pill to swallow for apartment dwellers who really want to decorate with houseplants but don't have the natural sunlight to support them. Signs that your plant is suffering from insufficient light include yellowing leaves, lack of new foliage growth, and excessive leaning towards the light source.
How to fix it: Move your plant to a new spot, closer to a window. Even if your window doesn't get much sunlight, it will still do the trick for low- and medium-light plants. (South-facing windows get the most daylight and are best for plants with high light requirements). Grow lights are also an option if you don't have much window space, though keep in mind that using grow lights daily for 10-12 hours could result in a bump on your electric bill.
3. Plants prefer 70-degree weather, too
Remember how I just said that houseplants do best when you keep them by a window? Well, that's true, except they don't like drafts in winter. Like most of us, they prefer a balmy temperature in the mid-60s to mid-70s, and freezing air creeping in around window frames can be enough make your houseplant metaphorically shiver. They also don't like super hot temperatures and can even get sunburned in summer sunshine if they're not the type of plant that likes lots of direct bright light (and a lot of common houseplants don't). Yellowing leaves and dropping blooms can indicate your houseplant is suffering from the chills, while wilting is a sign that it's getting too hot. If leaves are turning brown or looking scorched on the window-facing side but not the other, that's a sign of sunburn.
How to fix it: Make sure to seal up drafts during the winter—for me this means tucking an old knit scarf around the windowsill where I know cold air seeps in and closing the curtains at night. I also move my plant stand a few inches back from the windowsill. If your plant is too hot in summer, consider sheer curtains to create filtered light, or move the plant to a north- or west-facing window.
4. Over-fertilizing is worse than under-fertilizing
As plants grow, they extract nutrients from the soil, so it's important to replenish those nutrients from time to time by adding fertilizer—just don't get too enthusiastic about it. As a first-time plant parent, it can be tempting to dump on a little extra fertilizer as insurance, but if anything you should err on the side of giving your plant less fertilizer than the package directs. Over fertilization can burn the roots and paradoxically limit the plant's ability to absorb nutrients—you might notice blackened roots, dying and dropping leaves, fertilizer crust on the soil's surface, and very slow growth.
How to fix it: If you've recently potted your plant, you don't need to worry about fertilizer for a while since fresh potting soil will come with fresh nutrients. You also can slack off on fertilizing in the winter since your plant will be going dormant after the growing season. In spring and summer, you can apply a fertilizer designed for use with indoor plants. Liquid fertilizers are typically easiest to work with—Neptune's Harvest Organic Fish and Seaweed Fertilizer is a popular all-purpose option. Definitely follow the instructions on the fertilizer package and consider doing research on your plant species for more insight on what type of fertilizer to buy and how often to use it.