It’s going to cost more to take care of your lawn this summer.

Record-high fuel prices will make it more expensive to buy fuel for the lawnmower and other yard machines.

But high energy prices are also pushing up other landscaping-related items, such as fertilizer, which is derived from natural gas.

Fertilizer prices are up 15 percent to 20 percent this year, compared with last year, according to Joseph Castanera, a technical manager for TruGreen ChemLawn. That is on top of a 10 percent increase last year, he said.

TruGreen, based in Memphis, Tenn., provides fertilizer services for lawns.

Fertilizer accounts for about 35 percent to 40 percent of most care businesses’ chemical expense, he said.

Retail prices for fertilizers also have gone up because dealers are paying more to buy it.

The Scotts Miracle-Gro Co. increased prices to dealers for the first time in five years, said Jim King, senior director of communications and investor relations for the Marysville, Ohio-based lawn-care company.

Nitrogen is one of the three main components in many fertilizers. Natural gas is used in a complex chemical process to extract nitrogen from the air and synthesize it into fertilizer, said Kathy Mathers, a spokeswoman for The Fertilizer Institute, a Washington-based trade association.

About 70 percent to 90 percent of the cost of making nitrogen fertilizer goes to natural gas, she said.

The wholesale price of natural gas has risen dramatically during the past three years. The average “city gate price” — the price at the point where the gas is transferred from a pipeline to a local distribution company _ was $7.09 per thousand cubic feet in the first two months of 2005, according to the U.S. Department of Energy. That is 72 percent higher than it was in 2002, when the average price was $4.12.

Energy prices remain at or near record levels, and lawn-care companies are coping with the added expenses of fertilizer and gasoline in different ways.

When Kevin Green gives a customer an estimate for seeding or fertilizing a yard, he adds a clause that the price will be adjusted according to supply costs.

He owns Always Green Hydroseeding & Fertilizing of Warwick, R.I.

Green has to pass on those costs to stay in business. “It’s not like we’re putting any more money in our pockets,” he said.

For Lawn Beauticians of Cranston, R.I., the cost of transporting plants, bushes and trees to its nursery is rising dramatically.