Indoor plants add life and vibrancy to any interior, but there’s more to caring for house plants than the occasional watering.
Viva spoke with Richard DeGrandpre, owner of Plant Workshop Ltd, which oversees Auckland's inner-city indoor plant havens Monstera, Little Babies, MonsterPots, and Bonsai of New Zealand to get his tips on caring for house plants.
It turns out successfully caring for indoor plants is a little more complicated than watering, misting leaves and repotting them from time to time. If you’ve got a fern that’s forever limp or a peace lily that never blooms, you might want to consider the philosophical and psychological aspects of plant care, which “underpins people’s successes and failures in rearing a houseful of plants”.
“You can roughly classify people as having either a passive or active approach to plants,” says Richard. “Some own plants as decoration, wanting them to be static decor with the same needs as a paperweight. This is passive.
“Others have a more active approach, tracking the life signs and growth of the plants, and getting the rewards of noticing the particular occurrences of new growth. Those more in the latter camp, of course, have more success with plants, as they have more of a personal relationship with them and are not burdened by having to water and prune, or keep an eye out for plant pests like scale, mealybug and spider mite.”
So, asking your plants how their day was might not be so crazy after all? It's encouraged. Pay attention to your green mates and attend to their needs as you would a friend. Do they need some fresh air, a drink, a little walk around the house to a new spot? To some, plants are inanimate objects that add to the decor of their home, to others they’re a lush and fulfilling addition to home life. Those in the latter may be rewarded with healthier plants.
But now for some basics, because those plants really do need more than conversation and attention to care for them.
Viva: How often should I water my plants?
Richard: Overwatering is by far the greatest threat to plants. I believe people water too frequently for psychological reasons, i.e., watering to get it over with, so they no longer need to worry about watering, or about the plant getting dry and dying. This is the better-safe-than-sorry approach that alleviates the immediate concern but nevertheless leads to plants getting root rot. Damaged roots cannot deliver moisture to the leaves and this often leads to further overwatering, because people think the browning leaves are a sign of under-watering.
Ultimately, there is a small minority of plants that are unforgiving when they dry out (mostly ferns and ficus), but for most, drying out is the best way to avoid over-watering your plants. Nearly any plant that has any detectable moisture at the surface of the soil, or feels heavy in its plastic container, does not need watering.
How do I know if a plant needs repotting? How often should I be repotting?
If the plant is still in a plastic pot, you can squeeze hard around the base. It the plant is root-bound, it will be stiff, if not, it will compress. It’s best not to repot unless it’s very root-bound. The less excess soil, the warmer the root environment, and the better growth you get. Roots that are not in contact with soil are just being kept unnecessarily cool, with the soil acting as an insulator. Plus, with less soil, the less likely you’ll over-water the plant because it dries out faster.
Any tips for repotting?
When repotting, soak it well the day before, so its soil falls away from the roots, rather than tearing away. Cut away the plastic container first if need be, or cut the plant out at the edges of the ceramic pot with a saw.
Should I feed my plants with plant food or fertiliser and how often?
Only fertilise a healthy plant, and usually only do so when it’s been in the soil so long that the soil has lost its vitality. If you can’t repot, then fertilise (in the growing season). But fertilising has little to do with having healthy plants, many of which will essentially grow in water.
How much light and or sun do I give house plants?
All plants do better in more light (more energy), but some can’t take direct sun, and only some can cope with a very dark space. Plants should be placed in the environment they have evolved for. So when you buy a plant, get the correct info, and don’t take it home and put it in the wrong place, essentially asking it to ignore a million years of evolution. Cacti need sun, peace-lillys and fiddle leaf ficuses can’t handle direct sun. Dappled sun is nice if you can get it. Remember, more sun means more heat, usually, which means less humidity as the area warms each day. Indoor plants mostly prefer higher humidity so, for example, you get dry leaves on maidenhair ferns in the dry air.
Do I need to clean the leaves? How should I do that?
Wipe dust off the upper side of leaves with a moist but not wet cloth. Or take them all outside if you can and wash them with the hose. Dusty plants give plants a bad name.
Are there any pots/materials I should avoid when it comes to house plants?
It’s best to keep plants in plastic pots so it’s easy to repot and to check the well-being of the plant (just pop off the pot). Keep them in a ceramic cover-pot for decoration. Plants are light and humidity oriented: this should be the determining factor for placement, all else being equal.
What should I do if my plant is looking sickly?
Sometimes it’s a lost cause and maybe you can learn from the experience. Ask yourself, ‘What’s the likelihood it’s been over-watered and what’s the chance it’s been underwatered?’ Pick one, usually it’s the former unless it’s been sitting in water inside a ceramic pot.
Do different environments such as an apartment or a work office require different care for my plants?
Offices are often poor in light, and/or dry in the air because of air-con. Again, you need to match the plant with the conditions, which is why you see Z plants in offices, or dracaenas, which are very durable
My plant is on a lean. Why is that and what can I do?
Plants are not that smart in how they grow, so you often need to repot or re-orient a plant, or stake it. A monstera will grow further and further off to the side - take it out of the pot, shave the sides of the roots, and repot upside up. Don’t be afraid to prune the heck out of it. The plant will usually thrive with the attention.
What’s your favourite house plant?
The lady palm is a magnificent plant and so sturdy, but expensive. Very slow-growing. But not too common. They're tall, so often they take up little room, unlike the sprawling kentia palms.
Indoor Plant Bootcamp
Top tips for the most common house plants
Ferns need humidity and don’t like drying out.
Peace Lily will wilt, so that’s an easy sign of when to water.
Fig Leaf needs medium bright light or better, and will grow too tall and narrow if not pruned at the tip when mature.
Monstera is a no-nonsense, no-fuss plant — but needs regular pruning; easy to propagate.
Dracaena is an easy plant that likes all light conditions, is tall and narrow so a popular space filler.
Be hands-on with your plants, says Richard. Know them so you can see when something is new, or something is wrong. They thrive on neglect in terms of watering but they otherwise love all the attention they can get.