The best time to catch a problem with a plant is before it’s in your cart, not after it’s been sitting on your shelf for two weeks. A few minutes of checking at the store can save you from bringing home an infested plant, a root-bound one that’s already struggling, or one that’s simply never going to work in the light you actually have. This is a pre-purchase checklist — for what to do once the plant is already home, see how to acclimate a new houseplant.

Check the undersides of leaves and stem joints first

This is the single most important check, and the easiest one to skip because it means actually turning leaves over instead of just looking at the display from a few feet away. Pests like spider mites, mealybugs, and scale tend to hide on the undersides of leaves and tucked into stem joints and new growth points, not out in the open on top of the foliage where they’re easy to spot.

Look for:

• Fine webbing, especially in the crook where a leaf meets the stem
• Small white cottony clusters (mealybugs)
• Tiny brown or tan bumps that don’t scrape off easily (scale)
• Sticky residue on leaves or the shelf underneath the pot (honeydew from sap-sucking pests)
• Any tiny moving specks when you look closely, particularly on the undersides

A single infested plant brought home can spread pests to your entire collection within weeks, which makes this the check worth spending the most time on. See common houseplant pests and how to get rid of them for what each of these actually looks like up close. If a plant you otherwise love shows any of these signs, it’s not worth the risk to the rest of your plants — pick a different, cleaner individual instead, even from the same shelf.

Feel for firm stems and leaves

Gently press a stem near the base and a leaf or two. Both should feel firm and have some resistance. Mushy, soft, or squishy stems are one of the clearest signs of root rot already in progress, even if the leaves up top still look reasonably green. A plant that looks fine from a distance but feels soft at the base has usually been overwatered sitting in its nursery pot and may already have significant root damage you won’t see until you get it home.

Look at the soil

Take a quick look at the soil surface and, if you can, press a finger into the top inch. Soil that’s saturated and dark, has a sour or swampy smell, or shows visible mold or fungus gnats hovering around it points to a plant that’s been overwatered on the shelf — another sign to check for root rot before you commit. Dry, light, crumbly soil that pulls slightly away from the pot’s edges is a more reassuring sign, though it just means the plant hasn’t been recently overwatered, not that everything else is fine.

Gently check how root-bound it is

You don’t need to fully unpot a plant in the middle of a store, but many nursery pots slide loose enough to tip the plant partway out for a quick look, or you can check through the drainage holes for roots already emerging. A plant that’s mildly root-bound is normal for one that’s been sitting in its nursery pot for a while and isn’t a dealbreaker — but a plant with roots circling densely on the surface or pushing itself up out of the pot has likely been in that container far longer than ideal, and may need repotting immediately rather than after the usual settling-in period. See how to tell if a houseplant is root bound for the full set of signs and how to weigh whether it’s a problem for the specific plant.

Skip plants with a lot of yellowing or dropped leaves already

Every plant sheds an occasional older leaf, and that’s not a reason to walk away. But a plant with several yellowing leaves, visibly thinning foliage, or a scattering of dropped leaves already in its pot or on the shelf beneath it has been stressed for a while — from underwatering, overwatering, poor light, or pests — before you ever picked it up. You’ll have an easier time with a fuller, more evenly green specimen sitting right next to it than trying to nurse the stressed one back from a deficit before it’s even left the store.

Pick a plant for the light you actually have, not the one that looks best in the store

Store lighting is bright, even, and nothing like the single window or dim corner most plants end up in at home. It’s easy to fall for a plant that needs bright, direct light while standing under grow lights that make everything look equally lush. Before you shop, know roughly what light your space actually offers — a sunny south window, a bright but indirect spot, or something dimmer — and pick a plant suited to that, rather than assuming you’ll figure out placement after the fact. A gorgeous plant that’s slowly declining in the wrong light isn’t a better buy than a more modest one that will actually thrive where you plan to put it.

The five-minute version

If you don’t have time for the full checklist, prioritize in this order: flip a few leaves and check stem joints for pests, press the stem for firmness, glance at the soil for wetness or smell, and confirm the plant suits your light. Those four checks catch the problems most likely to spread to other plants or leave you with a struggling one within the first month.