There is still time to start your summer flower garden. Look in the nurseries for plants that love warmth: ageratum, marigolds, Vinca rosea , gloriosa daisy, portulaca, globe amaranth, celosia, petunias and zinnias. For shady areas, consider begonias, impatiens and coleus. If you prefer perennials, there are also some good hot-weather bloomers available.
Daylilies come in a range of heights and colors (cream and yellow, orange and melon pinks, lavender and mahogany reds) and can be combined beautifully with the deep-blues, gray-blues or whites of agapanthus. Deep-blue varieties are available at the Huntington Botanical Gardens, in San Marino ('Huntington Blue' and 'Irving Cantor'), and at the Los Angeles County Arboretum, in Arcadia ('Walter Doty'). The many variations of the Shasta daisy are also in bloom; canna flowers almost all year-round. Yellow or white lantana can be used to replace marguerites, which will start to look tired in inland areas.
Palms do best if repotted when the weather is warm and the days are long (this is when the roots are most active). It's also easier for them to come out of the shock of being moved. They should be kept in the shade, but if this isn't possible, pull up the fronds and tie them together.