Houseplant Buying Red Flags – Signs You Shouldn’t Buy Houseplants

You’d never buy a sofa without reading reviews first, and you’d never buy a car without taking a test drive. And even though a houseplant is a lower-stakes purchase, it’s important to thoroughly check it out before forking over any cash, too. While many plants do just fine in greenhouses, nurseries, home centers, and grocery stores, others can wind up looking a little worse for wear. Sometimes that’s just a sign that they need a little more light or water, but other times, there’s something more dire at play.

Whether those issues are root rot, too-tight quarters, or plant pests, they can be hard to detect at a glance. That’s why it’s important to know what to look for when you’re wandering around a greenhouse or fancy plant shop. A closer examination can help you find problems that could lead to heartbreak down the line (especially if you’re shelling out for a pricey rare plant).

Before you get attached to a new plant friend, you should be looking at the leaves, stem or trunk, roots, and soil for clues that might indicate potential health issues. Thankfully, those clues are easy to decipher if you know what you’re looking for. So here’s your list of seven important watch-outs, well-informed plant connoisseur. Put that plant right back down if any of the following common issues catches your eye.

We’ll start with an easy one. Lots of yellow leaves can indicate much larger issues at play. This plant could be over, or under watered. It could have pests, it could have been over-fertilized, or it could have been left in the wrong lighting conditions. Because you can’t really know which it is, this is without a doubt a ‘put that plant back’ moment.

If you spot just one yellow leaf on a healthy plant, it’s not necessarily a cause for alarm. Proceed with caution to the next round of examination.

Brown Leaves Paired with Wet Soil

Are the leaves on this plant crispier than a good potato chip? This could simply mean that it’s thirsty. Feel the soil — is it dry as a bone? If it is, you might be able to save that plant if you really wanted to. But warning: If that soil is damp while the actual plant is crispy, there’s a chance you’ve got more systemic problems. The plant could have root rot that prevents it from effectively taking in moisture, so that leafy friend should go back on the shelf.

Speaking of rot, double check those roots! In a small boutique nursery or greenhouse, you’ll want to ask first, but in a large garden or home center it is totally OK to carefully slip the plant out of its grower’s pot. Gentle tug that plant at its base and the root ball should come out; You may need to lightly squeeze the grower’s pot, too, to help it loosen up. Once you see the root ball, you’ll need to use your eyes and nose.

Take a sniff of the root ball (don’t worry, no one’s watching). If you smell something off — like a swampy or sulfur-tinged scent — in the soil, this plant could have rot. You’ll also likely notice that the roots look dark brown, rather than bright off-white. You might even feel that they are squishy rather than firm. If any of these ring true, put that plant back on the shelf and step away. While it’s possible to save plants with root rot, it’s difficult and not guaranteed.

If, however, you give the plant a big of a tug and the whole thing pops out whole, with lots of visible roots wrapping around the outside of the soil, that plant is root-bound. That means that the plant has outgrown its pot, and its roots are running out of places to go. Root-bound plants that look otherwise healthy can be rescued — just make sure to pick up a larger planter on the way out the door so that you can repot the plant at home.

The key saying to remember when examining roots: “Root rot, never bought; root-bound potting up and around!”

If you ever see tiny, white fuzzies on a plant you’re thinking about buying, please swear to me that immediately alert the staff to a pest infestation (and definitely don’t bring that plant home with you). These fuzzy white things are mealybugs, which can spell death for both the plant that you’re holding at the store and any other plants you have at home. These pests are little white bugs that often have a slightly waxy appearance; the fluffy, cottony white stuff around them is the casing of the hundreds of eggs they lay.

Mealybugs feed on the sap of your houseplants, causing leaves to yellow and curl thanks to tissue damage. They’re also extremely hard to get rid of, especially at higher levels of infestation.

Even if you don’t see mealybugs on a plant that you bring home, experts always recommend that any new plant be sprayed with your favorite Bacillus-based pest spray and quarantined from your other plants for two weeks to help prevent any wayward hitchhikers.

Dark Spots on Steams or Leaves

If your potential plant purchase has dark spots, they could be caused by something as simple as inconsistent watering. But if those spots are prevalent on all the leaves, it could be a sign of fungal infection. Put that baby back! You don’t need that in your life.

Even worse, little spots can be a plant-eating pest known as scale, which usually appears on stems as raised brown dots. Try scratching a bit of the spot off with your fingernail. Did it come right off? Scale! Do not bring that plant anywhere near your home — and for bonus points, let the shop owner know.

Soil naturally has lots of living organisms in it, many of which are beneficial. Some, however, can be a huge headache.

Take a close look at the top of the plant’s soil. Do you spot movement? Proceed with caution. These could simply be soil mites, which don’t cause much trouble — but most of the time, if you see anything camping out in the soil of a plant’s pot, it’s going to be fungus gnat larvae. These generally are more an annoyance than a danger, but if you have plant propagations or freshly planted seeds germinating at home, even a few fungus gnats can wreak havoc on these more delicate plants.

White Web Between Leaves

If you see webs outside, they usually belong to spiders. On houseplants, there’s another culprit: spider mites.

These webs are the tiniest strands usually found in nooks and crannies of a plant and accompanied by so-small-they’re-almost-invisible white or brown mites. (Seriously, they’re small — you’ll need to lean in close to spot them.) Spider mites are one of the most difficult things to get rid of on a plant without using a heavy-duty insecticide, and even then they can still win. If you’re seeing spider mites, there’s no way you should bring that plant home. Leave it behind and alert the store.

Once you start to learn what to look for while you’re plant shopping, you’ll start to understand why some plants you’ve brought home might have died very quickly after purchase while others thrive. Sometimes it has nothing to do with you, and everything to do with that plant’s life before you brought it into your sweet houseplant haven. A closer look can help set you up for success.

Cheryl Rafuse


Cheryl Rafuse is a professional gardener planting and designing in Beverly, MA. Her company Plant Magic Gardens focuses on ecologically conscious gardens filled with native plants and pollinator favorites. She enjoys a good moss patch and loves the scent of violets. Cheryl can reliably be found covered in dirt with weeds in her pockets, much to the chagrin of her partner and two lovely cats.

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