🍅 How to Grow Tomatoes in Containers (Colorado Style)

If your soil is terrible (and let’s be honest, it probably is), container tomatoes are one of the smartest moves you can make in Colorado.
But containers are less forgiving. You’ve got to be a little more dialed in.

Container & Soil: Bigger Is Better

First mistake people make? Too small of a pot.

Minimum 5-gallon nursery pot, bucket, or equivalent. Make sure your container of choice has drainage holes in the bottom.

Use a high-quality potting mix—not garden soil. My favorite is Fertilome Ultimate Mix.

Mix in compost, a good compost at about 20% by volume, and a slow-release fertilizer. I like EKO compost (if you don’t make your own) and Richlawn Grow Rich.

Espoma is another great choice for an organic, slow-release feed.

Small pots dry out too fast and choke roots.

Bigger containers = stronger plants and more fruit.

💧 Watering: This Is Where Most People Fail

Containers dry out FAST here.

• Expect to water every day in summer
• During heat waves, maybe twice a day
• Keep soil evenly moist—not bone dry, not swampy

If you only take one thing from this article, it’s this: don’t let them dry out.

🌿 Fertilizing: You Have to Stay on It

Nutrients leach out of containers quickly with frequent watering.

Feed every month with a slow-release granular fertilizer. Make sure your fertilizer of choice has added calcium to help prevent blossom end rot.

A cultural problem, not a disease. You can also use a calcium supplement like Fertilome Yield Booster. (Not eggshells—add link to April Myths).

Supplement with a liquid fertilizer once the plants are large and producing fruit. An excellent choice would be a Fish Emulsion.

☀️ Sun & Placement

Tomatoes need full sun (6–8+ hours)

Afternoon heat can get intense. Temperatures over 95F can inhibit fruit set. If your plants are flowering but not setting fruit, a workaround for this is to tap the flowers to release the pollen or use a Tomato/Pepper set spray on the opening flowers. Totally natural and not harmful to beneficials. Did you know that tomatoes are not bee-pollinated?

Containers near walls or patios can help hold heat early and late season

🗓️ Timing: Same Rules Apply

• Don’t plant before mid-May. Plant stocky plants.
• The advantage? You can move containers if needed during cold snaps

🧱 Support: Yes, Even in Pots

• Use cages or stakes—even for container plants
• Wind can knock pots over, so keep them stable

✂️ Pruning

• Prune indeterminate types to keep them manageable
• Remove lower leaves for airflow
• Don’t strip the plant bare—those leaves are feeding your tomatoes and shading the fruit from the sun to prevent sun scald.

❄️ Best Tomato Varieties for Containers

Go compact or early:

• Patio
• Roma
• Tiny Tim
• Bush Early Girl
• Celebrity (in bigger pots)
• Grand Slam
• Tumbling Tom (great for hanging baskets)
• Glacier

🔄 Determinate vs. Indeterminate (Container Version)

• Determinate:
  Your best bet for containers. Compact, easier to manage, and predictable. The plants don’t get as large.
• Indeterminate:
  These plants can get quite tall and top-heavy. They will need trellising or caging that is secure from blowing over in the wind.