5 Tips For the Healthiest Houseplants Ever, According to a Botanical Garden Expert

Bringing plants into your home can do so much more than add greenery to a room (though we can’t understate the power of a well-placed plant). Taking care of your plants can be an emotionally fulfilling and mentally enriching hobby. Science says that having plants in your environment is a huge mood booster; since plants are living beings, caring for them can boost our sense of purpose.

Of course, plants do have specific needs, and you can encounter somewhat of a learning curve for certain species. If you’ve always been curious about what it’s like to be a plant parent, this year of sheltering in place is a good time to start. But whether you’re new to houseplants or a seasoned grandparent to propagated cuttings, it’s always worth it to refresh your plant care know-how. Paul Blackmore, a horticulture specialist at the Atlanta Botanical Garden, tells Apartment Therapy that while one set of rules doesn’t apply to the maintenance and health of indoor houseplants, there are standard practices to keep in mind when learning to care for them.

Blackmore cautions against randomly buying a plant without any consideration for its required care level, as this often results in a sad looking plant and a very disappointed owner. “All plants are living things, and have evolved to live outdoors in their natural environment. Like all other living things, they had vital biological requirements and a set of conditions in which to flourish,” says Blackmore.

For people who are always on the go, Blackmore recommends philodendrons, peace lilies, aglaonemas, or a pet-friendly cast-iron plant, all of which are pretty low-maintenance and plenty forgiving. Just keep them out of direct sunlight, keep the soil moist, and feed them regularly, and they should last several years.

Plants must have light in order to carry out photosynthesis, the essential process that allows green plants to make sugars and grow. According to Blackmore, many plants need more light that they can get in most buildings, but there are a few that have evolved to survive in less bright and sometimes even shady places.

Blackmore notes that overloading your plants with premium sunlight can often do more harm than good. “Plants need light, but what they certainly don’t need is hours of hot, bright, direct sunlight, as found on the south-facing window ledges,” he says.

A good rule of thumb from Blackmore is to face the plant to the side of the window (unless it’s north-facing) so the plant gets partial sun in the morning and shade when it’s hot. 

No two plants are the same, so it makes sense that the amount of water each one needs will vary. Blackmore says the amount of water your plant requires will depend on which species it is (some species require a lot of water, while others, like umbrella plants, dracaena, aloes, and crown of thorns, not so much), the local conditions (see: humidity, light levels, and temperature), the time of year (plants tend to need more water in summer, as they are actively growing, and less in winter, when light levels are reduced), and the plant’s specific growth schedule (many plants require a dry season or may even go into semi-dormancy for the winter, like orchids).

Blackmore advises watering your plant only when it needs to be watered. “If it’s summer and the plant is actively growing, then it may need watering every second or third day,” he says. “Check the soil: If it feels dry to the touch, then it may need watering. Another way to tell is to pick the pot up and get an idea of how heavy it is. A wet plant will feel weighty.”

One major mistake people make when watering their plants is keeping the plant in standing water, which results in root suffocation. According to Blackmore, the best way to water a plant is to move it to a sink or place it in a basin and fill the pot to the rim with water. Allow the water to run through the soil and drain, then return the plant to its location. (This can only be done with pots that feature drain holes, which is something to consider when picking your plant’s home.) This will both hydrate the soil and drag air into the root mass, providing the plant with oxygen. 

A breakdown of plant nutrition generally consists of nitrogen (N), phosphorus (P), and potassium (K). Blackmore explains that plants use nitrogen as a key building block for leaves, stems, and other plant parts. Phosphorus “is a key component to the production of DNA for cell division; it is also essential to the manufacture of enzymes, proteins, and energy cycle within plants,” he says. “Potassium is essential to the general health, flower, and fruiting of all plants.”

The ratio of each nutrient in your soil or plant food should depend on the intended use of the fertilizer. For example, if flowering and fruiting is the desire, then you should look for plant food with higher ratios of phosphorus and potassium. According to Blackmore, a good rule of thumb for the healthy growth of houseplants is an N-P-K ratio of 15-9-12; he also suggests you water your plants the day before you feed them. What not to do? Blackmore advises against applying fertilizers to dry soil. Feeding is not a substitute for watering and could easily kill the roots if overdone.

Worried about getting things wrong? Don’t be—just look for products designed to help even the newest plant owners. “There are lots of slow release fertilizers designed specifically for pot plants. These products are more expensive, but easy and safe to apply so there’s no need for mixing, watering cans, and little risk of overdoing the dose,” says Blackmore. “They’re essentially time capsules. Apply the required amount to the pot and they will slowly release their nutrient over a set period of time, ranging from several weeks to several months. The one thing to remember is that they stop working if the compost becomes too dry.”

Though plant diseases are generally rare, they can still happen; Blackmore says these issues tend to be molds and mildews. “This occurs because the plant is growing in poorly ventilated, shady conditions. You need to figure out what the environmental issues are before reaching for the fungicides,” he says. “We prefer to prune out infected materials, but you can try the neem mix.”

Insects like scale and mealybugs, on the other hand, are slightly more common. According to Blackmore, they are small insects that form colonies and stay in one place by sucking the sap from a plant. Both of these will overpopulate on the plant, making it very unsightly and exuding an unpleasant, sticky liquid.

While Blackmore warns that controlling these pests can be difficult at home, they are possible to treat. “Physically remove the insect by hand or spray a soap and oil mixture” on the infected area, he says, adding that you can often buy pre-mixed solutions from a garden center. You can also try a natural pesticide like neem oil. If your plant has scale, you might not even need to buy anything at all: “Another treatment that is used in some places is to put coffee grounds on the surface of the compost in the pots,” Blackmore says. Yup, taking care of your plants is as easy as brewing a cup of joe!

The Apartment Therapy Plants vertical was written and edited independently by the Apartment Therapy editorial team and generously underwritten by Greendigs.