NEW YORK (AP) -- Garden centers enjoyed a pandemic boom, particularly with millennials, as people looked for outdoor activities during lockdowns. Now the question is, will those wannabe green thumbs stick with the habit.

In 2022, 80% of U.S. households took part in lawn and gardening activities, a five-year high, according to the National Gardening Association's 2023 National Gardening Survey. Spending on lawn and gardening activities rose to an average of $616 per household in 2022, an increase of $74 from 2021.

Danny Summers, managing director of The Garden Center Group, which tracks sales of about 125 centers across the country, said sales are up by about 25% compared with 2019. But the sales totals flattened out between 2022 and 2023.

The spring season is crucial, because garden centers can make about 60% of sales during the 12 weeks of spring, according to Summers. That's particularly true for centers in the North since there are fewer months to plant.

To regain the sales momentum, garden centers must navigate a number of challenges as another spring season kicks in. Chief among them are volatile weather and higher costs for labor and plant materials, which in turn has forced the companies to raise prices for customers.

One positive development: Younger households, particularly the 18- to 34-year-old age group and 35- to 44-year old age group, have seen larger increases in spending than older households, a trend that Summers thinks has legs.

"Our garden centers are just serving a new need that we don't see going away anytime soon, because this new audience is very much grounded in nature and plants and gardening," he said.

At Flowercraft Garden Center, a San Francisco garden center that is in its 50th year of operation, houseplants, vegetable starter plants and citrus trees are selling well, said general manager Lydia Patubo.

Since the spring season is so short, garden centers are at the mercy of the weather. Patubo said last year's unprecedented storms in the area put a dent in business. San Francisco saw record rainfall of nearly 34 inches during the 2023 "water year," which ended in September. That was good for an area suffering from a yearslong drought, but bad for garden center business.

"It was a rough year," Patubo said. "So, I'm hoping (this year) for less rain, better business," she said.

As spring kicks into gear, Patubo said smaller items - such as four-inch plants or six plants in a pack -- are selling better than bigger one gallon to 15-gallon plants because customers are spending less due to higher prices and inflation.

"The smaller stuff sells remarkably well, it's the bigger stuff that I need to move a little faster," she said. That affects her ordering from dozens of growers in California. "So, my ordering is way down, but the ordering for smaller products is way up."

At the East Coast Garden Center in Millsboro, Delaware, co-owner Chris Cordrey said weather is also a concern, particularly because so much of the center's business is compressed into a four-month period between March and June.

"We got a lot of rain last year, so that made it difficult," he said. "If you miss a Saturday during the busy time when it's raining or cold out, then that really hurts your sales overall."

While according to the National Oceanic and Atmosphere Administration, 2023 was overall the third-driest year on record, parts of the country saw above average rainfall. Meanwhile, there were a record 28 separate weather and climate disasters in 2023 that caused an estimated $1 billion in damages, such as heat waves, drought, wildfires and floods, surpassing the record 22 the U.S. had in 2020. All of those can affect plants.

Higher costs are another issue.

"What we're used to paying labor has increased tremendously," Cordray said. He hasn't hired fewer workers, with a staff of 200, but he created a new recruitment position and added recruitment software to help retain staff.

"And our garden supplies across the board have increased drastically. ... So we're definitely seeing a lot of increasing in our costs," he said.

To offset higher costs, he had to raise prices; for example, a flower in a one-gallon pot, a standard size, had sold between $5 and $5.50 but he had to raise that to between $6 and $6.50.

So far, customers are taking the price increases in stride. Container gardening- putting plants in containers in areas where ground space is limited -- newer "dwarf" size plants and fruit trees and bushes like blueberries and raspberries are popular.

"People are enjoying growing their own food and then harvesting their food," he said. Even though his sales have plateaued since the pandemic, he feels the 34-year-old garden center is in a good spot.

At Ooltewah Nursery and Landscape Co. in Chattanooga, Tennessee, which has been in business for 35 years, sales boomed during the pandemic and haven't slowed down since.

Vegetable and fruit plants are big sellers, including tomatoes and eggplants, said general manager Kat McGraw. Because of the garden center's location - two hours from both Atlanta and Nashville -- a lot of retirees have relocated there, and they have time to spend on their gardens.

Still, weather has been a challenge there too, including last year's drought and deep freeze, not normal for the area. A lot of plants were damaged.

Like elsewhere, costs have risen across the board, including costs for delivery and trucking, potting soil and even the wind chimes found in the gift shop.

"Everything has increased over the last two years," McGraw said. "I don't know of anything that hasn't."

But that hasn't discouraged her customers from spending, she said. The mild climate in Tennessee, weather events aside, lets people garden eight or nine months out of the year.

"People are still putting a lot of time into their yards, they all want a nice yard, and that's where they spend a lot of their time," she said.