Your Questions about House Plants, Answered by Colorado Experts

“Is your once-luscious prayer plant suddenly wilting? Do you break into a cold sweat when it’s time to repot? Have you seen—gasp—bugs on your pilea? Press pause on the panic button and see what the experts have to say.

The Question… My cats are twin menaces. How do I keep them away from my plants? —Geoff Van Dyke, editorial director, 5280
The Answer…“Pet stores sell sprays you can use to ward off your cat—the spritz makes the leaves taste bitter. I stretch aluminum foil or plastic wrap across the soil to keep animals from digging in the dirt too.” —Stephanie Esposito, Steph Floret
The Caveat…“Certain leaves dry out when you spray them, so you might just want to put them up high, out of kitty’s reach. Or opt for varieties that are nontoxic to cats, such as bird’s nest ferns. That way, you don’t have to worry about kitty getting sick.” —Esposito

The Question… How do I know what kind of soil I should be using for my plant? —@rossollo
The Answer…“Usually, you want your potting soil to be rougher than garden soil because the larger particles help it drain. Most garden stores sell a sterilized loam soil, which is a good base for the blend. Mix it with equal parts perlite.” —Paige Briscoe, ReRoot Gardens
The Caveat…“Succulents and cacti thrive in sandy dirt—they’re from the desert, after all. Shoot for equal parts sand, soil, and perlite. You can even add some orchid bark for plants that want extra drainage.” —Briscoe

The Question… How do I know if a plant needs to move to a larger pot? —@liajane
The Answer…“You should only see soil through the container’s drainage holes. If the only thing visible is roots, your plant is root-bound and needs a bigger pot. Gently squeeze the outside of your pot to loosen the soil, grip the stem near where it enters the dirt, and gently wiggle it out. Place it into the new pot and fill in soil around it.” —Victor Sosa-Meza, The Plant Room
The Caveat…“Roots won’t grow faster if you put them in a huge pot. Unless your plant is massively root-bound, I’d choose a pot that’s around two inches larger in diameter [than the previous pot].” —Sosa-Meza

The Question… How do I know if my plants have pests? Should I treat them if they do? —Jessica LaRusso, managing editor, 5280
The Answer…“Look at the greenery and soil. If you see white bugs that look like tiny grasshoppers, you have aphids. They reproduce quickly, so make sure to isolate your plant and spray it with neem oil or another pesticide. If you see fine, cobweblike clusters on your leaves, that’s a sign of spider mites. Spray them with pressurized water to dislodge them, then apply neem oil.” —Amber Hage-Ali, The Terrorium Shop
The Caveat…“Sunshine can burn leaves recently treated with neem oil, so make sure you keep the plant in a shadier area.” —Hage-Ali

The Question… My 10-year-old rubber tree drops leaves daily. Why? —@su-faye
The Answer…“Unless you’re over- or under-watering, it sounds like a fertilizer issue. Most plants want to be fed. I love fertilizers with fish and seaweed—they’re organic and won’t burn your sprouts like a chemical fertilizer. Earthworm castings work well too. You can find either at a gardening store.” —Annie Huston, The Urban Nursery
The Caveat…“You don’t need to feed your plant during the winter. I recommend beginning in March, when you see new leaves emerging from the stems. Sprinkling organic fertilizer on top of the soil or even mixing it into the top layer a bit every month works well.” —Huston

Troubleshooting

You know your flower child is trying to tell you something—but what? Victor Sosa-Meza of the Plant Room helps you decode its signals.

1. The tips of the leaves are turning brown.
Crispy leaves usually mean your home isn’t humid enough. I’d get a nice humidifier to deal with the problem.

I don’t have a ton of space. Is there another option?
Your second-best option is going to be a pebble tray. Take a large tray that’s as wide as the widest part of your plant. Add a layer of pebbles to the bottom, and set the potted plant atop them. Pour some water into the tray, but not so much that your plant is sitting in a puddle. Evaporated water particles add humidity.

Can’t I just mist them?
I don’t recommend it. It’s not as effective, and the droplets can catch and magnify the light, burning leaves with soft, fuzzy filaments on them.

2. The plant has a weird film on it.
Is it dust? If so, that’s normal, but you should gently wipe it off with a cloth. Dust blocks sunlight and inhibits the leaves’ ability to photosynthesize. Or, if it’s time to water your plant, stick it in the tub and turn on the shower to lukewarm. The spray rinses the leaves and gives the plants a drink.

So…the film looks more white and cottony.
Sounds like you might have a fungus. Isolate the infected foliage from your other plants to prevent an outbreak. Trim and remove the infected leaves. Spray the entire plant with a fungicide product. To treat root rot, remove the plant from its container and gently rinse or trim away any mushy roots before repotting.

3. The plant has long, floppy stems instead of being full and lush.
We call that “legginess,” and it’s pretty common. Are the vines getting enough sun? If not, you’ll notice the long stems leaning toward the window. Just move it closer to the light source, and it should start to look fuller. I gave it a go, but my plant is still leggy.

I gave it a go, but my plant is still leggy.
It’s probably time to prune it to promote new growth.

Take scissors to my baby?!
It’s OK! You can pinch the stem between your thumb and forefinger, just above the topmost node. The break in the stem stops growing, so the plant instinctively sends nutrients to either side of the node, creating more branches in the stem and making it look fuller.