Despite your best efforts, the houseplants you bought at the beginning of stay-at-home orders might be struggling. The leaves might have turned yellow or droopy, while spots or burnt-looking edges could have you thinking you’re a bad plant parent.
That’s not necessarily true. Oftentimes, houseplant woes are a byproduct of good intentions gone wrong, explains Bodie Pennisi, a horticulturalist at the University of Georgia. Troubleshooting your plant issues can be as simple as recalibrating how you provide care.
Speaking A Plant's Language
“In my opinion, the top problem that develops is insufficient light,” says Pennisi. Each plant species has its own needs, but generally, what we perceive as “high” lighting conditions doesn’t really cut it for our green housemates. As you might remember from school, light is crucial for photosynthesis, the process plants rely on to churn out sugars. Those molecules fuel plant growth and development. Without enough light, plants draw on sugar reserves to meet survival needs and can slowly starve to death, Pennisi says.
Symptoms of insufficient lighting can kick in quickly. New leaves might be smaller and paler than old ones, or the plant might not grow at all. In an effort to direct its limited sugar reserves to new leaves, the plant might let mature foliage die. To avoid this, you can supplement sunlight with fluorescent or incandescent bulbs, or pick a plant that is well-suited for the amount of sun exposure your home provides.
If insufficient light is the biggest problem, the second largest issue is overwatering, Pennisi says. Too much water deprives plant roots of oxygen. Pennisi knows what you’re thinking. “You're like, wait a minute, I thought that oxygen is what the plants give to the animals,” she says. “Well, yes and no.” Plants make oxygen, but they also need it to make use of stored sugars. Roots get the essential ingredient from air pockets in soil, and excessive moisture drives the oxygen out. If this happens, leaves yellow or droop, and roots can go brown. It’s best to gauge how much water your plant needs by sticking your finger an inch or so into the soil. Feeling moisture lets you know your plant is just fine on hydration.
There are a few other, less common maintenance problems budding gardeners might run up against. For example, houseplants generally like more humid conditions than people do, as most come from more tropical areas, Pennisi says. Plants lose their moisture to the air through a process called transpiration, and the low humidity of air conditioned rooms can increase how fast the foliage releases water. Some people try and solve this problem by misting plants or dripping water onto underlying gravel, but these are temporary fixes, Pennisi says. Airflow in a home is rapid enough to negate that added moisture. “You just have to resign yourself that there will be some edges of the leaves that will dry out.”
Infrequently, people over-fertilize their plants, too. Those added nutrients are essentially salts, Pennisi says. In too high of quantities, they can burn plant root tissue. And if the plant does absorb the fertilizer, the additives can accumulate in leaves after water evaporates — and leave brown, crispy burns in those areas, too.
This kind of injury can leave plants susceptible to pest infestations. Like humans, plants are covered in microorganisms that can be helpful or harmful. “Plants are just covered with good guys and bad guys, as I like to call it,” Pennisi says. “And the bad guys are sitting there, waiting for an [opportunity for] entry.” Damaged tissue is the opening those pests are waiting for.
Besides maintaining overall plant health, one way to ward off infestations or infections is to investigate your plants before you buy them. And when Pennisi says investigate, she means it — inspect the stem and look under leaves for signs of insects, crawling or sitting still. Pop the plant out of its container, if you can, and assess the roots. Do they smell earthy? That’s a good sign. If the (otherwise white) tangles have black or brown spots or are soft to the touch, the plants have too much moisture and could set you up for future issues. “That would not be a plant I'll be spending my money on,” Pennisi says.
Adjusting To A New Home
If you take your new prized possession home and give it everything it needs — the right light, the right amount of water, the right moisture — you might see the general shape and color of your plant change over time. New leaves might be slightly longer and wider than their older counterparts, or a darker green. The space between each new tendril of foliage, called internodes, might lengthen. These could be signs that your plant is adapting to its new home.
For breeders, the faster full-grown, healthy plants get into stores, the better. Especially when it comes to larger varieties, growers pump cuttings or seedlings full of fertilizer and supply all the water and light they could possibly need to proliferate at breakneck (well, for a plant) speeds. Ideally, these growers also wean their plants off these intense growth periods, Pennisi says, since too quick a shift can shock the plant and make it drop leaves. A healthy adjustment is slow, and it might continue once the plant is in your house. What exactly those shifts look like depends on the species and what traits breeders encourage, Pennisi says, as the industry is always experimenting to produce plants that make increasingly seamless transitions into households.
One way a new plant owner can try and detect subtle changes is to keep a diary. Every day, make a note or two about how the new leaves look, as that’s where your plant is investing all its energy, Pennisi says. It might abandon the older leaves as it grows ones compatible with new, lower-light conditions, so that older foliage might go yellow and die off.
For more specific advice on the exact plant species you chose, check in with the nursery you bought it from, or look for resources from industry associations. It benefits those groups for your efforts to be successful, Pennisi points out. And if it turns out you just couldn’t salvage your plant, that’s okay too. Even a dying plant teaches you about care — and what to do the next time you put a new potted friend on your counter.