Tomato Small Talk.

Apr 8, 2022

By Penny Pawl, UC Master Gardener of Napa County


Spring is imminent, so it is time to be planning your summer garden. Napa County Master Gardeners will be offering a large variety of organic tomato seedlings for sale on Saturday, April 9. The online sale was on April 3. The varieties were chosen because they do well in Napa Valley, with several new varieties available this year.


Have you considered growing tomatoes in pots? Many people have reported doing this successfully. Here are some tips if you'd like to try it.


First, determine the mature size of the tomato variety so you can pick a pot, bucket or barrel large enough to accommodate the root system. Tomatoes are generally the deepest-rooted plants in a vegetable garden. Also, you need a pot big enough for a tomato cage or other supports.


Make sure the container has enough holes for good drainage as tomatoes don't like wet roots. If you need to improve drainage, drill ¼-inch holes in the bottom of the pots before you add soil.


Because soil can wash out of pots, I line the bottom with newspaper before adding soil. Colored newspaper has clay in the ink so avoid using that. You can also use old window screen.


Tomatoes in containers need consistent watering. The soil in pots dries out quickly. I have found that the soil can be wet on top of the pot and dry at the bottom. When you water, make sure the water is penetrating to the bottom of the pot.


Use a potting soil rich in phosphorus and potassium. You can buy potting soil at nurseries or mix your own. I usually make my own from a mix of sandy loam, perlite or red lava rock and compost. Aged chicken manure is a good addition. Aim for a pH. of 5.5 to 7.5 for the best results.


Once you fill your buckets or pots you probably won't want to move them, so make sure you place them in an area with lots of sun. Tomatoes need sun to be at their best. Put a cage around your tomatoes as soon as you plant them.


You'll need to know whether the varieties you've chosen are determinate or indeterminate types. Determinate tomatoes are probably a better choice for container growing as they stop growing once flowers appear. Indeterminate varieties continue to grow even after the flowers appear. If you want to grow tomatoes in a hanging pot, an indeterminate type is probably the better choice.

I once grew a cherry tomato that was still producing in late November. It was an indeterminate variety that kept growing, flowering and producing tomatoes that I ate right off the plant.


This year, I am planning to try an indeterminate cherry tomato in a hanging pot. I see them in the garden catalogs. When summer ends, I may be able to move the plant to my greenhouse.


If you are planting tomatoes in hanging pots, make sure the hanging wires are strong enough to hold the pot as the tomato matures.


Tomato Sale: Napa County Master Gardeners will hold their annual tomato plant sale on Saturday, April 9, from 10 a.m. to 1 p.m. or until sold out, at 1710 Soscol Avenue, Napa. Twenty-seven varieties will be available.


Got Garden Questions? Contact our Help Desk. The team is working remotely so please submit your questions through our diagnosis form, sending any photos to or leave a detailed message at 707- 253-4143. A Master Gardener will get back to you by phone or email.

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