It took Donna Gardner 12 years and dozens of dead plants to learn that fertilizer is hazardous to ferns.

It turns out they’re so easy to care for they don’t even like TLC.

That’s good news for plant lovers who don’t exactly have green thumbs.

Now, there’s added benefit for those who have plants around their office — people who surround themselves with foliage are happier than those who don’t, according to a study from Texas State University-San Marcos.

If you’re not on speaking terms with plants, not to worry. There are plenty of easy-to-care-for varieties.

Gardner, greenhouse manager and grower for Sunrise Garden Center, 1501 Learnard Ave., says ferns must be watered often, but they are otherwise self-sufficient.

She suggested four plants in particular that require little work to keep in good condition. Ivy, peace lilies, spider plants and Swedish ivy only need water once a week and fertilizer once a month. As tropical plants, they last in the home all year round.

Ivy and peace lilies should be placed near an east- or north-facing window, while spider plants and Swedish ivy require a south- or west-facing window. Gardner says an additional benefit is that they are considered air-cleaning plants.

Cacti are also easy to maintain, Gardner says, as long as they are not overwatered. They don’t require much fertilizer.

Likewise, orchids are a good choice for those who want to add a little color in their houses without having to do much work, Gardner says. They require low to medium amounts of light.

“You always see them on a coffee table in the middle of the house,” Gardner says. “They bloom for four months. One plant will get you all the way through winter.”

Air plants are another alternative. They can sit anywhere and don’t require a pot or even soil — just a 30-minute dunking in water once a month.

“It’s the ultimate easy plant,” Gardner says.

When it comes to outdoor plants, Mike McLoud, nursery and tree farm manager Lawrence Landscape, 600 Lincoln St., suggests barberry shrubs and junipers.

Barberry shrubs can tolerate extreme soil. They should be placed in sun or partial shade, and they need moderate amounts of water.

Junipers thrive with a lot of sun and good drainage. They are very hard plants and can withstand extreme weather. It is important to avoid overpruning them, though.