GENEVA is a compact city of parks. Visitors can find most of them, including the extensive public gardens, as they stroll along the banks of beautiful Lake Geneva. A good place to start a garden tour is in the city's oldest one, the Conservatory and Botanical Garden. It began back in 1817 (though in a different location) and was moved to its current 34-acre spot on the right bank of the lake. About 15,000 plant species (Switzerland itself has only 3,000 native species) are carefully labeled with their common and scientific names, family groupings, and geographical origins.
One of the least-known activities of the Botanical Garden staff is their work of saving endangered species.
Botanists bring back cuttings and seeds from all over the world for propagation. These specimens are not only ornamental but also commercial - valued for their uses in fuel, food, and chemicals.
Although species preservation is an increasing activity of the garden, its principal raison d'^etre is to provide visitors with the opportunity to learn about the plants.
And what a place to learn - with plants displayed in a setting enhanced by interesting sculptures by various artists.
The garden is well organized. ``Useful plants'' are arranged according to their industrial, aromatic, culinary, or pharmaceutical properties. ``Biological curiosities,'' such as variegated or honey-bearing plants, mutants, or those with unusual reproductive systems, are grouped in another section. Then comes the colorful rhododendrons The display here of these difficult-to-grow flowers could make any amateur gardener feel insecure.
The Botanical Garden rockeries are a special attraction. Here plants are arranged from a geographic perspective, and one can go see specimens from the Balkans to the Caucasus, to Asia Minor, the Himalayas, the Far East, Oceania, and the Americas.
Two of the greenhouses are open to the public. The winter garden greenhouse features luxuriant tropical and equatorial plants. It includes the plants that produce such familiar products as cotton, pineapples, bananas, coffee bushes, and cocoa.
The orangery greenhouse, on the other hand, specializes in plants that grow in the European climate. In this acclimatized environment the specimens reach great size and live much longer than they do outside.
The garden also features a deer park shaded by ancient oaks, along with a waterbird section where cranes and peacocks strut and preen. A newly built aviary houses parrots, African thrushes, and other tropical birds in a heated environment that can be seen in all seasons.
Throughout the year, the Botanical Garden presents open exhibitions.
In the spring, tulips are on display, and in the summer there are geraniums, begonias, salvias, carnations, and African marigolds.
The summer season culminates in a show of dahlias.
Some avid gardeners will be interested in the garden's store, which sells packets of special seeds acquired by an exchange with scientific establishments and institutes throughout the world.
If you arrive in June, your second stop on a garden tour can be the International Rose Competition at the Parc la Grange. More than 12,000 roses of 180 varieties surround the Louis XV-style house, and it's considered the finest rose garden in Switzerland.
Then, on to the the plants of the Parc la Grange itself, which adjoins the Parc des Eaux-Vives and a fine springtime display of rhododendrons and azaleas, presented by the Dutch people after World War II.
The Parc Villa Barton, La Perle du Lac, Parc Moynier, and Parc Mon Repos are adjoining parks on the edge of the lake that have fine trees, flowerbeds, and lawns.
You may want to linger and enjoy the attractive gardens, but be sure to leave enough time to visit the Flower Clock in the Jardin Anglais (English Garden).
It is the most notable feature of the seven-acre park, which has the famous Jet d'Eau fountain in the background, spraying water 460 feet into the air above the lake. More than 6,000 plants are used each year, and the clock keeps perfect time.
What else would you expect in Switzerland?
Watching the city workers as they carefully water their gardens, we feel a twinge of personal concern. How are our own neglected plants doing back home, several thousand miles away?
If you go to Geneva on the first day of August, you'll be there for a national holiday.
Two weeks later there's a weekend celebration with fireworks on the lake and street dancing. Flower-covered floats, a tradition of the city, are a special part of the parades during these festivities.
For more details about the city, contact the Swiss National Tourist Office, 608 Fifth Avenue, New York, NY. 10020.