Start your strawberry and tomato plants indoors about six weeks before the last frost in spring. Fill two starter trays with potting soil, and sow your seeds or bulbs at a depth of ¼ to ½ inch. Sow tomato seeds in one tray and strawberry plants in the other. Label your trays so you know which contains each plant. Keep the soil moist each day, and provide a grow light to seedling for about 16 to 18 hours a day.
Choose a location outdoors that gets about 10 hours of direct sunlight each day to plant your strawberries and tomatoes in the spring, after all chance of frost has passed. Till the soil with a shovel to a depth of 8 inches, and add 2 to 3 inches of equal parts peat moss and compost to the soil. Begin on a cloudy and cool day so that you don't stress out your strawberry plants.
Add a balanced 10-10-10 fertilizer to the area where you want to plant your tomatoes and a 16-16-16 fertilizer to the area where your strawberries will be.
Rake soil in the area where your strawberries will be to form 1-foot-high hills that are spaced 12 inches apart for each plant.
Transplant your tomato plants by digging a trench deep enough to cover the root and stems to just below the first set of leaves. Place each plant at an angle in the trench, and cover the roots and stem with soil. Press the soil firmly around the stem to just beneath the first set of leaves. Space each planting 1 to 2 ½ feet apart.
Dig a hole into each mound to transplant your strawberry plants. Create a hole large enough for the roots. Release the root ball of your strawberry plant from the starter tray. Fan the roots out in the hole, and bury them up to the crown. Make sure the crown is even with the soil surface to prevent damage to your plant. Transplant one strawberry plant in each mound.
Place about an inch of straw mulch around your strawberry and tomato plants to prevent weeds and retain water. Moisten the soil immediately with water. Water your tomatoes two or three times a week, and give your strawberries an inch of water only once a week.
Pinch flowers off your strawberry plants the first season so that they grow a strong root system for the following season's harvest.
Add a side-dressing of 10-10-10 fertilizer at a rate of a pound per 100 feet to your tomato plants when fruit appears. Repeat the application after three weeks and then again after six weeks. Harvest fruits every two days when they gain full color and are firm.
Place a 6-inch layer of straw over strawberry plants in the fall to protect them from winter weather. Harvest all green tomatoes to ripen indoors before the first frost.