Northern California Coastal & Inland Valleys
It is possible to get another set of blooms from your annual plantings if you cut them back while the weather is still warm. Petunias especially benefit from a mid-season grooming. If you don't want to look at stubs and twigs, simply cut back one third of each plant every week. That way you will always have some flowers to look at while new growth is coming on. Personally, I like to get it all over with at once. Perennial plants such as coreopsis also benefit from an overall "hair-cut."
Provide citrus trees with a mid-summer boost to ensure a crop of flowers. Dibble a citrus-specific fertilizer into the soil around the drip line and water it in well. Keep citrus trees watered during hot weather.
Fertilize Shade-Loving Plants
Shade-loving plants don't use water as quickly as plants grown in full sun. They also don't use fertilizer at the same rate. A good way to fertilize plants growing in the shade is to use a slow-release fertilizer which is usually applied directly into the soil surrounding the plant. These products will release fertilizer at a slow rate for as long as three months when the plants are watered.
Mint (Mentha spp.) requires partial shade and regular water. These plants perform best in light, medium-rich, moist soil. They creep along the soil by underground rhizomes; it is recommended that you plant in containers or use a barrier surrounding the mint bed so they don't become a pest.
Calla Lily Care
Calla lily (Zantedeschia aetheopica), prefer a shady location, slightly acid soil, and regular water during growth and bloom. Following the bloom, they require a rest period in which water is withheld. Overwatering causes the bulbs to rot in the soil. Leave them undisturbed (no transplanting) until overcrowding causes decline of vigor and bloom quality, then dig and divide.