What’s this mystery plant? Plus, help with fungus gnats, pothos and a too-tall ponytail palm

DEAR JESSICA: We have a bush in our backyard that we cannot identify. It gives beautiful rose-type flowers at this time of year and almost looks like a holly bush. This has been a nine-year mystery. Do you know what it is?

— Linda Cortes,

Lake Grove

DEAR LINDA: That’s a Camellia japonica.

Native to Asia, the evergreen spring bloomer is prevalent in the South, where it’s the state flower of Alabama. Our climate here in zone 7 is considered borderline for camellias, but, as your nine years’ experience demonstrates — they certainly can thrive here. There also are new cold-hardy varieties that thrive all the way to New England, and are worth seeking out.

Spring is the best time to plant camellias, and they perform best in light shade and slightly acidic, well-draining soil.

For those who just want to enjoy the view, Planting Fields Arboretum State Historic Park in Oyster Bay houses the largest collection of camellias under glass in the Northeast, and they’re on display from December through March.

DEAR JESSICA: We have had a pothos indoor plant for more than four years, but it is not growing. It is still alive, but size-wise it is the same as it was when we bought it. What can we do to make it grow? Also, around these plants, we are seeing lots of small, flying insects. We put soap and vinegar in a cup, which kills many of them, but still a lot more gets produced. We are not overwatering. How do we get rid of the flies?

— Vipul Gheewala,

Floral Park

DEAR VIPUL: It sounds like your plants are infested with fungus gnats — and they’re after your soil, not your plants. Fungus gnats thrive in moist conditions, so even though you don’t believe you’re overwatering your plants, it’s possible you might be. It’s best to water only when the soil around the roots — not on the surface — becomes dry. Test for moisture at the root zone about once a week by sticking your finger into the soil up to your second knuckle. Water only when it feels dry. Put each plant in the sink and water until it drains from the bottom (be sure pots have drainage holes). It’s also best to rinse the leaves with water to remove dust and disturb any insect eggs.

Even if you’re already watering correctly, if you’ve recently repotted your plants, it’s possible gnat eggs were present in the potting soil you purchased. No matter — the best thing to do now is dump the soil, gently rinse the plant and roots with water, and clean the pot with a 10 percent bleach solution, then repot with fresh, sterile potting mix. Place the plant in a different room until the gnats are eliminated.

Your vinegar trap is an effective one, so either keep the trap in the area until they’re all caught or try using yellow sticky-tape traps to eliminate any gnats that remain in the house and prevent them from laying eggs in your new soil, which would start the cycle all over again.

Pothos require bright, indirect light, so they’ll thrive best near a window that’s covered with a sheer curtain. Direct sunlight will burn their leaves.

To give your plants an extra boost, fertilize them every 12 weeks from spring through fall with 19-16-12 fertilizer, following package directions. Good luck!

DEAR JESSICA: I have a 40-year-old ponytail palm tree that I brought back from a trip in 1975. It’s now about 8 1⁄2 feet tall. I store it in my garage in the winter. It’s getting too tall to store at this point. A friend said I should cut the trunk about two-thirds up and re-root it. Can I do that?

— Fred Wicks,

Amityville

DEAR FRED: Your ponytail palm, which is sometimes called elephant foot palm, isn’t actually a palm at all (this is why common names can be misleading). It’s a Beaucarnea recurvata, and in this case, even the botanical name can lead to confusion: Some botanists include the plant in the Nolina genus. It’s not even a tree — it’s a succulent in the agave family (related to the source of tequila). Regardless of its lineage, you can slow the rate at which it grows by reducing fertilizer and waterings, and keeping it slightly root bound. That is, postpone moving it up to a larger pot when its roots begin to get crowded.

Cutting the plant mid-trunk (using a saw) is possible — but you should know it will result in a multibranched plant. That’s not a bad thing, just different from what you currently have. You also should be prepared to be patient, as shoots could take several months to begin growing.