Flower Planting Guide in Northern California

Local Climate

Evaluating the local climate is critical when selecting which flowers to plant. Plants will thrive in appropriate conditions, but will struggle if the weather is too hot or cold. According to the USDA map for California Planting Zones, the coastal and central regions of Northern California fall within planting zones 9 and 10, which means temperatures almost never drop below freezing. Residents living in the Sierras can expect much colder weather and are more likely to be in zones 6 or 7, where the average annual low temperature drops to 0 degrees F.

Factors like geography and landscaping can create microclimates within each temperature zone. Each microclimate has a slightly different weather pattern that will impact the ability to grow certain flowers. In general, north-facing gardens will receive less light and more moisture than sunnier and drier gardens facing the south. Gardens located on hills will be windier and drier than gardens located at the bottom. Trees can help block wind, while fences and houses can act as heat sinks by absorbing warmth during the day and radiating that heat at night.

Most of Northern California experiences warm dry summers with little rain. As a result, it's important to choose drought-resistant plants to avoid excessive watering throughout the summer. Native plants are not only well suited for this task, but they also help provide habitats for native animals like birds and beneficial insects.

When planting a garden, it's good to have a mix of perennials and annuals. Annuals are flowers and plants that grow only for a season, and then die after spreading their seeds. Some types of flowering annuals include snapdragons and poppies. Perennials grow back every year, from the same set of roots. As a result, they don't have to be replanted, but may need pruning. Some flowering perennials include lavender and irises.

In 2006 the master gardeners in Santa Clara County, Calif. grew and tested several types of flowers and ornamental plants. Master gardeners are people who have undergone a certified training, and typically volunteer to help other home gardeners. Some of the top choices selected by the Santa Clara County's master gardeners included the sunflowers known as 'Angel's Halo', 'Chocolate Cherry' and 'Music Box'. They also recommended zinnias, globe amaranth and clarkia.