Accresence

In some plant descriptions, you may read that they ares “strongly accrescent” or “scarcely accrescent.” What does that mean?

Accrescent refers to a plant or plant part that continues to get larger as it gets older.

Most plants and plant parts are hardwired to stop growing once they reach a specific size. These sizes vary by individuals because of irrigation, nutrition, temperatures, sunlight, pests and disease, but the estimates are generally true. Other plants, or plant parts, never stop growing in size, or they may continue to grow beyond the rest of the plant until some developmental stage is reached.

Degrees of accrescence

The degree to which a plant is considered accrescent can vary quite a bit. In some cases, only the peduncle, or flowering stem, is accrescent, and then only until the flower reaches maturity. These plants are rated as slightly accrescent.

Tomatillo (pixiemay) Pixabay

Most commonly, it is the calyx that is accrescent. Calyx, or sepals, are the green modified leaves that surround the base of a flower. The papery covering seen on tomatillos (Physalis philidelphica) is an example of moderate accrescence of the calyx. When the calyx stops growing, your tomatillos are ready to harvest.

Plants that are rated as “strongly accrescent” take the challenge to grow very seriously. These plants just keep getting bigger. Giant sequoias are an extreme example of accrescence.

‘Grizzly Giant’ Giant Sequoia (Mike Murphy) CC BY-SA 3.0

Understanding accrescence can help you identify unknown plants. It can also help you to know when to harvest your tomatillos!