From gardens with European elements to those with a California twist, this year's Gamble Garden Spring Tour will showcase "Neighborhood Gardens of Old Palo Alto" on April 25 and 26.

The 23rd annual tour supports the operations and maintenance of the Elizabeth F. Gamble Garden Center, a nonprofit community horticultural mecca in Palo Alto.

Tickets will include access to five private gardens in Palo Alto in addition to a plant sale, boutique and advice from garden docents. Visitors can also purchase tickets to enjoy a special lunch at Gamble Garden.

One of this year's gardens is the European Classic, with various garden areas functioning as extensions of the house. Palo Alto landscape designer Betty Lee organized the garden into roughly six unique areas: the front yard, shade garden, kitchen garden, pool side, terrace and knot garden.

Although it was re-landscaped two years ago, the garden has matured and exemplifies a cohesive blend of Mediterranean, European and California elements.

In the front yard, Lee wanted to create a more formal atmosphere for the striking entrance. To do so, Lee borrowed elements from a monastic garden by placing terra-cotta pots of oranges near the doorway and planting climbing roses along the wall. Medieval monks typically grew fruits, vegetables and medicinal herbs in the monastery gardens, and the combination of fruit trees and roses in the front yard emphasizes the medieval notion of the practicality and beauty of plants. This theme is further reinforced through the row of olive trees lining the garden. The bushy topiaries that are sculpted in the shape of lollipops near the front steps add a classic European touch.

Walking to the right of the house leads to the shade garden. To take advantage of the naturally shady spot, delicate ferns, elegant dogwoods and evergreen clematises, which yield bright white flowers, were planted in the small spot next to the kitchen. Above the garden, clay pots hang over the black iron railing from the windows.

Hidden behind a Spanish-styled stucco wall is the kitchen garden. As the sunniest spot in the garden, various herbs and fruits grow in this roomy space. Opening the wooden gate reveals tiny rows of oregano, lemon verbena, fennel, strawberry, blueberry, sage, grape and blackberry vines. A stone bird pond accents the garden, in addition to the rustic brick and wood archway that leads to the pool and terrace.

By the pool, the shade from bamboo trees acts as a natural screen from the neighbors while providing ample shade from the sun. Deep lilacs, sunny poppies and bushy thyme line the fence, and past the pool is the terrace where much of the outdoor entertaining is done. Collections of glazed pots were placed near the dining table, and above the fireplace, a friendly iron sun looks over the garden. Plush wisteria grows over the deck covering, and a rope ladder somewhat hidden behind the leaves adds whimsy to the dining area.

Lee designed a small lover's knot garden behind the terrace. Knot gardens originally evolved from the monastic herb gardens; today, they are patterned gardens that are generally grown with various herbs, shrubs and flowers. Lee's knot garden was designed as a square, in which boxwood bushes were again arranged in alternating colors. To add hot Mediterranean colors to it, she brought flaming red tulips into the patterned garden. Next to it, an antique park bench offers a quieter spot in the garden.

Each of the garden rooms combine classical and whimsical details, and walking through it can feel like exploring various scenes of "A Midsummer's Night's Dream" production.

Other gardens on display this year -- all within walking distance of Gamble Garden, with docents on hand to answer any questions -- include:

* English Redux: Built in 1924, this English Tudor home underwent a major re-landscaping in which the garden walls were pushed out to increase the size of the back yard. Today, the garden is reminiscent of an English cottage garden but maintains the casual look and feel of a California garden. It contains a "secret garden," herb garden and eclectic collection of bronze and marble sculptures around the pool. (Landscape designer: Carolyn Ordonez);

* 1925 Italian Villa: Influenced by Italian colors and themes, the garden offers a quiet retreat in addition to the spa. Re-designed hardscape, including rounded pathways and low rock walls, contrast the lush landscape. To accentuate the hardscape, the owners display large rocks from the Trinity Alps, a designated wilderness area of California, which provide a unique focal point for the garden. (Landscape designers: Mary Gordon and Associates);

* New Family Manor: Highlights of this two-story Colonial manor include the shade garden in the front yard and intricate stonework and decking in the back yard. As the new home for a young family, it's a sophisticated yet cozy garden that can be easily used to entertain both kids and adults. (Landscape designers: Laurie Callaway and Connie Lefkowitz);

* Cityscape: As a "Category Four Historic Registry" home by Birge Clark, this house has undergone several renovations under several owners. Today, the elements of the garden have been used to dampen street noise and increase privacy, and it's surprising to learn that the garden, which now grows vibrant herbs and flowers, was originally a car-repair pit. Be sure to check out the shade garden and lovely Clarke style fireplace. (Landscape designer: Toni Heron).

Leslie Huey, spring tour chair, said the tour is a "beautiful way to experience California gardens and people. ... One of the things that make Palo Alto unique are these kinds of events. In California, you can experience the outdoors all year long, so these gardens are just like stepping into another room of the house."

What: "Neighborhood Gardens of Old Palo Alto," 23rd annual Gamble Garden spring tour

When: Friday, April 25, and Saturday, April 26, 10 a.m. to 4 p.m.

Where: Five private gardens in Palo Alto, plus Gamble Garden Center, 1431 Waverley St., Palo Alto

Tickets: $35 in advance for non-members, $30 for members; $40 day of tour

Lunch: $15, reservations due by April 18

Info: Call 650-329-1356 or visit www.gamblegarden.org