Tuesday, May 7, 2019

Growing Tomatoes in Containers

This year’s Great Tomato Growing Experiment: is this small area (4’x16’), adjacent to a north-facing fence, truly the sunniest spot on the property?

After monitoring my entire full sun-deprived Folsom yard for nearly three years, this one spot, near the garage, may be the one area that gets more than eight hours of direct sun a day, perfect for growing tomatoes.

The dilemma (well, two dilemmas, actually): because it is a concrete surface, the tomatoes must be grown in containers; and, how do you avoid water stains on the concrete when the barrels drain?

Solution: use a big container (in this case, half barrels with five 7/8” drain holes drilled through the bottom) and place that container on top of a catch basin with several 3/4” holes drilled on the side rim on the back side, allowing the water to drain from the catch basin to the  12” wide gravel area along the fence line.


The prototype catch basin was at the suggestion of radio guest Lori Ann Asmus, who decorates Christmas trees professionally (you can see her work during the holiday season at various lobbies in public buildings, including the downtown Sacramento’s Citizen Hotel).
The catch basins were, in reality, meant for placing beneath Christmas trees to catch any water overflowing the tree holders. They are available wherever fine Christmas tree accessories are sold (such as Emigh Hardware, in December).

The barrel/catch basin combo have shims under the front side, allowing a gentle slope towards the fence, coaxing the water to go out the back side of the holes in the catch basin and into the gravel. So far, so good.

Regarding the container dilemma: when planting thirsty summer vegetables in full sun, try to use the largest containers, preferably made out of something that doesn’t allow heat build-up, such as plastic (it’s not unusual for the soil in an unprotected plastic pot in full sun to reach temperatures in excess of 140 degrees on a day in the upper 90’s). A wood barrel works perfect for that purpose. Plus, the greater volume of soil in a barrel (as opposed to a 15-gallon plastic pot) also helps the plant avoid stress from dried-out soil if you miss a watering during 90 and 100-degree days. And, more soil means more room for root development.

Because a container plant may need water every day in the summer, I’ve given these two tomato plants (a Champion 2 full size tomato and a very popular grape tomato I have never tried before, Juliet) their own watering system: a battery operated timer on a nearby faucet with a Y-adapter. Connected to the timer is a short, half-inch drip line run, going along the backside of the barrels.

Connected to the half inch line: quarter inch tubing snaked through a small hole on the lower backside of the barrel, and topped off with an adjustable drip bubbler/sprinkler in the middle, which sends out 6 or 8 even streams of water in a circle. Unfamiliar with drip irrigation systems? Entire kits are available, such as this.


Pro tip: run the quarter inch line in the barrel BEFORE filling it with a good quality potting soil. (By the way, “Pro Tip” = “lesson learned the hard way”).

The tomato cages are made from 4’x5’ sheets of concrete reinforcement wire, 6” mesh (for easy reaching of the tomatoes). Bend the sheets in a circle and fasten with plastic zip ties. Or, use your barbed wire tool (what? everyone doesn’t have a barbed wire tool?) to cut off the vertical 12-gauge wire ends on one side, and then bend the free horizontal wires around the opposite side.

Watering containerized plants is tricky, and must be increased or decreased more frequently, depending on the weather. Having a nearby faucet/timer/drip system in place helps ease those adjustments.

Fertilization can also be tricky. Because of the leaching nature and frequent watering that an easy-draining potting mix needs during the summer, fertilizers must be applied more frequently. Note that “frequently” does not mean “more fertilizer”. If, for example, the directions on your slow-release vegetable fertilizer package advises fertilizing with a certain dosage once a month, modify it to meet the needs of your container plant: cut the dosage in half, and apply every other week.
Don’t forget that topping that containerized plant with a few inches of a bark mulch can help maintain soil moisture on a hot day and also keep the soil temperature moderate.


  1. I've grown semi-dwarf Meyer lemon and a hybrid tea rose in a half wine barrel, which worked sort of ok, but the roots still got hot. And the oddest thing was that one of the barrels began to decompose, so we had to move the lemon tree out of it, quite a hassle. I've got the same situation, small yard, too much shade, etc.

  2. Mixed my own this year, utilized some existing soil which still looked good and rich, no signs of fungus, peat moss, perlite, black cow manure and added a good potting mix to top it off. Adding a good fertilizer and garden lime in the mixture. Cut off bottom stems and leaves off stem and buried it that much deeper in soil. Great blog with good advice.

  3. Great information
    How many tomato plants should occupy a container?
    I am at the time to transplant my plants and dont want to over croud they in the new pots
    Thank you
    Stay safe

  4. One plant per container .........best

  5. It took three years to work out where the sunniest spot was ? Hahaha