There are many reasons why certain plants should not be planted together. Sometimes it is a matter of height. For example, a tall tomato plant will steal the sun from smaller plants nearby. Or it could be a matter of moisture. Mint, a water seeking plant, and a desert cactus will not do well next to each other since they have conflicting needs.
Another problem is plants that are susceptible to the same diseases. For example, I live in a very humid environment and have problems with a fungus on my squash. If I plant melons too close to the squash, they will also be infected. By keeping them separate, the melons survive long enough to produce a crop.
Additionally, there are plants that chemically damage other plants or prevent their growth. These plants are called allelopathic plants. They leave behind chemicals that can harm or kill certain other plants. Many of the plants mentioned in this article are allelopathic. You may be planting these plants together and then wondering why your plants aren’t doing well, especially if you have a small garden where the plants are all snuggled in together.
Allelopathic plants make planning your garden more difficult. Most home
Originally posted on Ask A Prepper