Yellow tomatoes have a sweeter flavor than red tomatoes because they have a slightly higher sugar content. This makes them a popular variety of tomato to grow in the home garden in Southern California. However, the number of varieties of yellow tomatoes to choose from is small. The varieties of tomatoes recommended by the University of California Division of Agriculture and Natural Resources to grow in Southern California are the large Lemon Boy Hybrid and the small pear-shaped tomato known as Yellow Pear. Yellow tomato plants can be planted in Southern California from April 1 until July 15.
Take a soil test to find out what the soil is lacking for optimal tomato production. This is done by contacting your local County Agricultural Extension Office. The Extension Office will help you with the proper procedure for taking an accurate soil test as well as information about where to send the sample for testing.
Locate a well-drained area for planting the yellow tomato plants. Keep in mind each plant needs 36 inches of spacing between plants. Also, the location needs exposure to a minimum of six hours of uninterrupted sunlight each day.
Clear the area of all undesirable plant growth and loosen the soil to a depth of 12 inches with a shovel, hoe or tiller. Spread a 1- to 2-inch layer of compost over the planting area along with the soil amendments recommended on the soil test. Work the compost and soil amendments into the top 6 inches of soil, then rake the area until it is smooth.
Install tomato trellises or stakes to support the tomato plants. The recommended yellow tomato plants are indeterminate, which means they grow into long vines up to 6 feet or more. If plants sprawl on the ground, the fruit in contact with the soil will rot and attract insect pests. A stake made of bamboo or other sturdy material 1 to 2 inches in diameter and 10 feet long with one end buried 2 to 3 feet in the ground is acceptable, as is a well-built trellis. The trellis must be strong enough to withstand high winds when the tomato plant gets large. The tomato plant is tied to the support with plastic garden tape or strips of cloth as it grows.
Plant the yellow tomato plants with 80 percent of their stems buried to create a sturdy plant. Roots will form along the buried stems. This is done by planting the plants at an angle with their root base no more than 6 inches below the ground. Pinch off any leaves that are below the soil surface. Only the top cluster of leaves should be visible above the ground after planting. The plant will straighten after a few days.