By Sommer Cartier, for Let’s Talk Plants! July 2023.
Six Tips for Planting and Growing Tomatoes
Summer is here! And with it, plump juicy homegrown tomatoes. In San Diego, we are fortunate to have the perfect tomato climate. With an ideal combination of sunlight, heat, and an extended warm season, even the most challenged gardener can produce a healthy bounty of this sweet tender iconic summer crop.
While the growing conditions in San Diego provide higher odds for success, there are several strategies that can be practiced improving tomato-growing skills and experience bigger and better yields. Below are a few to get you started.
Determinate or indeterminate?
Before planting tomatoes, select the variety that’s right for the growing conditions in your yard. Consider the size of your garden. If you like growing tomatoes but lack ample space for full-size plants, try growing determinate or compact tomato varieties. These tomatoes are bushy and have genetic characteristics that limit their growth to about three or four feet in height, making them ideal for small gardens and containers. Oregon Spring and Celebrity tomatoes are two great options for determinate tomatoes. You might also consider cherry or patio tomatoes which can thrive in 5-gallon containers.
Some seed companies, such as Renee’s Garden, specialize in compact tomato varieties which can be great for patio or balcony gardeners.
For larger spaces, you have the option of choosing determinate and/or indeterminate tomatoes. The beauty in planting indeterminate tomatoes is they will produce tomatoes for a longer period. You also have a larger selection to choose from since most tomatoes fall under this category.
Phosphorous is your friend!
Of the three plant macro-nutrients [nitrogen (N), phosphorous (P), and potassium (K)], phosphorous is the nutrient that focuses on growing strong roots and lots of flowers and fruit. Rather than using a typical high nitrogen vegetable fertilizer, opt for the organic granular tomato fertilizer that’s slightly higher in phosphorous (the middle number on the bag). It provides a form of slow-release phosphorus that tomato plants can access for several months without piling up excess nitrogen. While plenty of nitrogen will create big beautiful leafy tomato plants, it will lead to fewer flowers and fruit.
Tickle those roots
Often, when transplants are removed from their containers or six-packs, their roots are tightly bound in circles, forming a tangled mass. To encourage the roots to spread out into the existing soil and access critical nutrients and water, it’s important to loosen them. This can be done by using your fingers to gently pull apart the root ball.
Unlike other vegetables, tomato plants are able to form roots all along their stems, resulting in extensive complex root systems that can better handle stress and access soil nutrients. To encourage the growth of these roots, known as adventitious roots, …
(of a root) growing directly from the stem or other upper part of a plant.
… remove the lower leaves of the plant and bury as much stem as possible, leaving the top third of leaves and stem above ground. Over time, the plant will send out new roots along the portion of the stem that’s covered by soil, creating a stronger more resilient plant.
Tomato flowers are self-fertile and have the ability to pollinate themselves. However, they need vibration to knock the pollen off the anthers to fertilize the flower and produce a tomato.
The Beach Boys - Good Vibrations. Official Music Video for Good Vibrations (1966) performed by The Beach Boys. https://youtu.be/apBWI6xrbLY
While strong winds can do this, bees, butterflies and other pollinating insects do a far better job. Encourage pollinating friends in your garden by planting lots of their favorite flowers such as borage, lavender, pineapple sage, and African blue basil.
Remove the lowest leaves
To help improve airflow and reduce the chance of disease, remove the leaves along the bottom twelve inches of the stems of indeterminate tomato plants and tie up any low hanging branches. Leaves that are close to or touching the ground can be susceptible to fungal spores. Also, remove any yellowing or unhealthy leaves from any location on the plant when pruning.
Now that you have a few more growing techniques, you’re sure to have your best tomato growing season yet!
Editor’s note: This is not the first time, nor will it be the last, that Sommer and others have written about tomato gardening in our newsletter Let’s Talk Plants! To prove the point, here’s an unexhaustive list of links to read more:
Article found in Let’s Talk Plants! January 2008, No. 160, page 8, SDHS_Jan_08.pdf (sdhort.org) titled Ethylene and the Flavor of Tomatoes by Carl Price and Ellen Reardon.
Article found in Let’s Talk Plants! April 2009, No. 175, page 7, SDHS_April_09.pdf (sdhort.org) titled Plants That Produce - Boy, Do I Love Tomatoes! By Richard Frost.