No matter how many gardening tips you read up on, or how tune with your inner Mother Nature you might be, caring for a houseplant is not an if-then kind of undertaking. What we know: Watering is good (with restraint), and sunlight is good (depending on what kind of world your plant's ancestors grew up in). But when branches droop or shrivel, what else can be done?
Repotting—the act of finding your houseplant a new home—isn't always the solution, but it's an important form of houseplant maintenance that's often overlooked. (Potting up, or "up potting", is the act of moving your plant to a larger home; more on that later.) With a little help from Jesse Waldman at Pistils Nursery in Portland (who once taught us how to make a terrarium that would actually stay alive), we learned all about why it's worth your time—and how to do it.
Why Repot a Plant?
First things first, what's the point of this activity? If your plant's looking a little sad despite your religious devotion to its proper watering and sun cycles, repotting it might just be the way to perk it up. "There are a ton of reasons it could be getting droopy," Jesse concedes, "but repotting [including pruning the roots] is going to promote fresh root growth, and you'll be adding fresh soil, which adds nutrients."
In the wild, plants can spread their roots as much as they please (or at least until they run into competing roots). But in a pot, a plant's growth is hampered, and as a result, there's a chance that your plant is root-bound: "When you pull your plant out of its pot, or at the nursery, and there’s a lot of white roots wrapping around and around, it's root-bound," Jesse explains. Certain plants, like those in the Philodendron family (including monstera deliciosa) are especially prone to this condition—though they don't seem to mind it. The problem with root-bound plants is that watering them effectively is nearly impossible. And this could mean that your plant isn't getting any water, and that its roots are wet, which encourages fungi to grow. Not an ideal environment!
In a case of root-bind, roots grow thick and tough and wiry within the pot, creating a lot of air pockets in the soil; when you add water to a root-bound plant, it drops right through without actually moistening the roots. When you're watering, does the water go straight through the soil and out the bottom of the planter? Your plant might be root-bound. (Succulents and cacti—or plants like Steighorn Ferns or Jungle Cacti—aren't as prone to the condition, as their roots serve the plant differently than other houseplants.)
How to repot a houseplant:
- Remove the plant from its present home: With your hand securely at the base of the plant, tip it out of the planter over a spread out piece of newspaper, letting any extra dirt fall away. Shake it out as much as possible, so the dirt falls away from the roots.
- Tend to the roots: Evaluate the roots before you: If they're root-bound—or if any of the roots are brown and black, an indication that they've been overwatered or infested with bacteria or funghi—use a sharp knife or shears to cut away any the bad parts. "I’ve heard it’s safe to take away as much as a quarter of the overall root mass," Jesse says, though she personally errs on the side of slightly less. By removing some of these bad roots, you're making room for new (nutrient-rich) soil and making water more accessible to the roots. If the roots are not terribly bound or otherwise traumatized, you can simply loosen them up with your hands (this is sometimes called "agitating") before repotting.
- Consider your soil: Whatever you do, don't use dirt from the yard as potting soil, as it can be "spent" from a lifetime of hosting other plant, or contaminated with funghi or bacteria. Instead, choose fresh potting soil or cactus soil with added sand and pumice (the latter only for cacti and succulents). If you have composting soil you'd like to incorporate, go for it—but no more than 10% of the overall soil composition should be organic matter.
- Repot: If your planter has a hole at the bottom, you can choose to add an optional (but encouraged) layer of pebbles, rocks, or even packing peanuts for added drainage (if the pot doesn't have a hole, it's even more important that you create this drainage layer). Next, add a layer of fresh potting soil, the plant itself, and more potting soil filled in around the sides. Position the plant within the soil just as it was before, rather than adding soil at a higher level or letting the plant protrude more than in its last home.
- Water cautiously: Be carefully when first watering your plant, moistening the soil rather than fully saturating it. Whether you pruned the roots or just tousled them with your hand, "part of repotting is damaging the roots," Jesse explains, which makes them much more prone to overwatering.
Now relax. At first, your plant might not look perkier—"it's likely in a little shock!"—but give it time to adjust to its new home before worrying.
What about "potting-up"?
Maybe your plant is starting to look a little ridiculous in the pot you've got it in (Jesse's even had plants topple over because their foliage was so much heavier than their pot). In this case, you'll want to find your plant a slightly larger home: "As a general rule of thumb, you want to move your plant really gradually," Jesse cautions, recommending a pot that's only one or two inches larger than its current container. "You don’t want to take something form a 4-inch pot to a 10-inch pot," he says, "as all that extra soil with no roots [to drink up all the water] will stay really wet and rot your plant."
How do you tend to droopy plants? Share your go-to remedies in the comments.