Timing is Everything

• Both sweet peppers and tomatoes grow better from indoor starts.Hemera Technologies/AbleStock.com/Getty Images
  
  Sweet peppers and tomatoes have similar growing times and require similar growing conditions. Transplants from indoor starts work better than seeding directly in the garden and give a more even distribution. According to the University of Missouri, peppers should be planted two weeks behind tomatoes because they require more heat. Tomatoes generally can be set out after the last freeze, but peppers need temperatures between 60 to 75 degrees to set fruit
  
  

Sharing the Same Soil

• Mix compost to create nutritious, well drained soil.Jupiterimages/liquidlibrary/Getty Images
  
  Both sun-loving vegetable plants thrive in well-drained soil. Ample organic material in the soil benefits both tomatoes and sweet peppers. This can be achieved through incorporating composted manure, kitchen compost or spent mushroom compost. Too much nitrogen can cause lots of green foliage to grow at the expense of flowers for fruit . Heavy clay soils will be more useful to these vegetable plants when tilled with a top soil/sand mixture.
  
  

Common Enemies

• There is a downside to so much similarity. Sweet peppers are plagued by cucumber beetles, aphids, and spider mites. Tomatoes suffer damage from the same pests and share blossom end rot and viruses that beset peppers. Do not plant tomatoes and sweet peppers together in the same plot year after year. Rotate crops every season and keep an eye open to potential infestations.
  
  

A Few Good Neighbors

• Petunias are good neighbors to tomatoes and sweet peppers.Jupiterimages/Comstock/Getty Images
  
  Sweet peppers and tomatoes can be helped out by a few good neighbors. Basil loves living next to tomatoes and sweet peppers as well as carrots, radishes, melons, petunias and lettuce. Companion planting mixes plants that aid and support each other by repelling injurious insects, attracting beneficial bugs and retaining moisture in the soil by creating living mulch. There are diverse ways to plant tomatoes with sweet peppers by adding more garden acquaintances.