Tennis's No. 1 Aims at a Grand Slam. INTERVIEW: IVAN LENDL

THE world's No. 1 tennis player has little time to watch spring transform his garden in Greenwich, Conn. Having won the Australian Open in January, Ivan Lendl knows he's the only man who could win tennis's Grand Slam in 1989 (Australian, French, and United States Opens, plus Wimbledon). He's already hard at work. International tennis has no off-season, save a couple of weeks at Christmas. Many players spend that time traveling to the Australian Open and related tournaments.

For top players like Lendl, now is the time to sharpen up for the big tests of late spring and summer - the French Open, Wimbledon, and the US Open.

It was in Melbourne this past January, in courtside temperatures of 135 degrees F., that Lendl won his first Australian championship and regained the No. 1 ranking he had lost to Sweden's Mats Wilander in last September's US Open final.

The Czech-born star has now won seven Grand Slam tournaments altogether, including three French Opens and three US Opens. He has yet to win the title every player craves - Wimbledon.

``Of course I'd like to get Wimbledon more than anything else right now,'' he said. ``And getting the Australian makes it even more wanted because then I would have won all four - even though not in the same year.''

Ivan chatted amiably with this reporter before an early season tournament. In the last few months he has become one of the freest talkers on the tour. Press conferences are often a riot, especially when journalists have to work hard to get Lendl to talk tennis instead golf or hockey, two other abiding passions in his life.

That sense of fun has been sharpened by his growing confidence in the use of English, especially his command of the American idiom. He now has time to play with ideas instead of words, and he has become the master of the snappy retort.

Does he have a favorite Grand Slam venue?

``I like every single one of them for special reasons. I like the US Open because I get to stay home. I like the Australian because I get to play golf, and I have so many friends in Melbourne, and I really enjoy it. I like the French for the simple reason that it's the first one I won.

``And I like Wimbledon because it's so special, and I'm really starting to enjoy London. I feel more at home there than I did three or four years ago.''

Is this the year?

``Wimbledon?'' Then, with an appearance of nonchalance: ``Oh, I don't think too much about it right now. I just work on my game, on certain things which I hope will help my game. But I will start worrying about Wimbledon two weeks before.''

Lendl will certainly not be worrying about the spectators at Wimbledon (June 26 - July 9), whom he regards as the most knowledgeable in the world.

``They understand the game,'' he explains, ``and know exactly what to expect from the well-known players. And they never interrupt the matches as some spectators in other countries do.''

Lendl appears to have recovered fully from his injuries of last year, when he won only three Grand Prix tournaments, and no Grand Slam event. He has set himself a rigorous training schedule, including plenty of bicycling.

``I'll try to be in shape,'' he said, almost to himself. ``And the only person who really knows whether I'm in shape is me.

``I like to have proper time off for rest and preparation. I like to practice somewhere where no one bothers me and I can really concentrate. Being at peace with yourself is very important for every tournament - and that's how I'll try to start.''