Prune Those Tomato Plants!

Gardener’s Notebook

By Joshua Burman Thayer


Tomato plants thrive in our Bay Area Mediterranean climate. They grow an amazing amount for an annual, and their vining branches can become very dense and also shoot out great distances with the increased light at the summer solstice. Your job as a tomato plant tender is to increase the plant’s airflow and access to light. Pruning will boost the health and vigor of fruiting tomatoes while reducing habitat for bugs and molds.

Get your hands on a clean pair of floral scissors or other light garden scissors. (Do not use regular bypass pruners or house scissors, as these damage the skin of plants.) Then take a few minutes to look at your tomato plants. Take notice of green growth for its color, vigor, and abundance of flowers. Identify branches one by one and ask yourself these three questions:

 1.Does this branch have flowers? If yes, then LEAVE IT ALONE.

 2.Does this branch have fruits? If yes, then LEAVE IT ALONE.

 3.Is this branch just a shoot of green growth? If yes, then cut it off the plant. You will find these types of branches make up around 10–30% of the plant. By pruning these out, you will help keep the plant resilient as it reaches out into space.
Be aware that tomato leaves spread a soil-borne disease called verticillium rot. Therefore, be sure to green bin or compost the pruned parts of the tomato plant.

Notes: For those of you just now planting your summer 2019 tomatoes, you won’t need to thin them until perhaps mid-to-late July. If you have not caged your tomato, do so ASAP.

The Gardener’s Notebook is Joshua Burman Thayer’s monthly column for East Bay Appetizer. He also contributes longer articles for Edible East Bay’s print magazine, all archived at Look for Joshua’s food forest article in the Spring 2018 issue of Edible East Bay, and check out his design site: