Many companion plants have different properties that give advantages to other weaker plants and assist others to grow.
Some may possess substances that repel diseases and protect the other plants around it creating the opportunity for healthy plant growth, whilst others are important for the reproduction process of other plants around it through enabling pollination processes to take effect.
This can be done through the attraction of insects which in turn carry the necessary elements for the pollination process to begin. Plants that are native in an area can assist to attract those insects that are familiar to them.
There is minimal care needed when growing companion plants with other plants that have no defense mechanisms from diseases. Other companion plants are important for their role in the provision of nutrients to the soil and ultimately to the plants around it.
Certain perennials improve the soil texture by their nature to grow long roots as well as provide the necessary nutrients like nitrogen needed by other plants. Some may provide fertilizer properties when they wither or decay.
Other companion plants improve flavor. A good example is the basil plant which help to improve the flavor in tomatoes whilst repelling mosquitoes and other pests.
Such plants have properties that can be used as pesticides against harmful pests without losing the benefits that they bring.
Companion plants like garlic helps repel aphids near roses. They are able to accumulate sulfur, a fungicide which helps in disease prevention. It possesses properties that can be absorbed by other plant roots with a low concentration requirement for repelling insects. These are excellent to plant in a garden of various vegetables that do not need much effort in care.
Whilst they are of great value to most plants and act as repellants to insects it is important to note that most companion plants are harmful to humans and care must be taken where they are planted.
The four o’clock plants are harmful to both humans and animals whilst they provide the benefit of eliminating beetles which eat on the foliage.
Companion plants help bring a balanced system to a garden through the integration of both plants and animals though it is necessary to note that they may be toxic to domesticated pets and humans. Some retain moisture for other neighbor plants to use or to allow for seedlings to grow.