March: What to Do in Northern California
White, Hazel, Sunset
Buy rhododendrons The renovated rhododendron garden at the San Francisco Botanical Garden is coming into bloom, and its designer, Georgia Madden of Feyerabend & Madden Landscape Design in Emeryville, recommends these early-flowering, easy-to-grow species: Rhododendron arboreum, a small treelike accent with red flowers and large leaves; R. 'Noyo Dream' for its overall form and creamy pink blossoms; and R. 'Sabrina Adler' with clusters of pale pink to white flowers for a vigorous but not too large foundation planting. These and many others are available from Sonoma Horticultural Nursery (3970 Azalea Ave., Sebastopol; sonomahort. com or 707/823-6832; no mail order).
Green your garden Shop for eco-friendly landscape ideas at this year's San Francisco Flower & Garden Show. Display gardens, seminar topics, and the marketplace will feature native plants, edibles, drought-tolerant garden ideas, and sustainability-related products (Mar 18-22; entry fee $16 in advance, $20 at the door; San Mateo Event Center, 2495 S. Delaware St., San Mateo; gardenshow.com or 800/569-2832).
Stock up on orchids Even those who don't love orchids will be blown away by the Pacific Orchid Exposition, where you can check out more than 150,000 of these prized plants, many of which are available for purchase (Mar 6-8; entry fee $12 in advance, $14 at the door; Festival Pavilion, Fort Mason Center, San Francisco; orchid sanfrancisco.org).
Grow herbs Sunset climate zones 7-9, 14-17: As soon as frosts are past, plant culinary herbs such as chives, cilantro, dill, mint, oregano, parsley, rosemary, and thyme in a sunny part of the garden.
Plant tomato seeds Zones 7-9, 14-17: Start tomato seeds indoors on a sunny south facing windowsill early in the month, or about six weeks before the last expected frost. Organically grown seeds of 600 heirloom tomato varieties are available from TomatoFest Garden Seeds (tomatofest. …