NEW YORK — Wal-Mart hopes the same winter storms that kept shoppers away in the winter will bring them into stores in the spring.Starting Friday, Wal-Mart is having a weeklong sale of up to 50 percent on more than 60 outdoor items, including lawn mowers and mulch. The world’s largest retailer said the move, which pits it against home improvement rivals Home Depot and Lowe’s, is aimed at luring shoppers who are looking to restore patios and gardens battered by severe winter weather. Retailers don’t typically discount new spring merchandise so quickly and aggressively, opting to cut prices slightly throughout the season. This spring, however, will be more important to many retailers that were hurt by strong winter storms that kept shoppers indoors and forced stores to close hundreds of locations. Industry watchers say other retailers are likely to follow Wal-Mart in offering promotions on home improvement merchandise, which has high profit margins. “This is trying to get growth,” said Craig R. Johnson, president of retail consultancy Customer Growth Partners. “The early bird catches the worm.” Johnson said Wal-Mart is taking a page from Home Depot, which has offered a similar spring sale for years.Home Depot and Lowe’s, the two largest home improvement chains, declined to comment on Wal-Mart’s move. But Amanda Manna, a Lowe’s spokeswoman, said: “Our expertise in home improvement allows us to serve customers as a partner throughout an entire home improvement project, from inspiration to completion.” In the past, Wal-Mart Stores, based in Bentonville, Ark., typically offered discounts on outdoor items or special buys throughout the season. This sale, which ends March 29, marks the first time it has pulled the items together to kick off a spring sale, Wal-Mart said. Among the items that will be on sale: a seven-piece Mainstays patio furniture set for $298, $15 stacking sling chairs, $88 Kingsford charcoal grills, and $144 lawn mowers — brands like Murray and Snapper. Shoppers can also find five bags of Miracle-Gro garden soil for $10 and bags of mulch for $1.97 each. During the height of the winter weather, Wal-Mart closed more than 200 stores. And its U.S. discount stores posted a 0.4 percent decline in revenue at stores open at least a year for the fourth quarter, which encompasses the winter months.