How to Grow Tomatoes at Home Even If Your Outdoor Space is Just a Fire Escape

There’s nothing better than biting into a fresh, juicy tomato still warm from the sun—except maybe growing that tomato yourself. As long as you have a bit of sunny outdoor space, like a patio, roof deck, porch, backyard, or fire escape, you can grow your own delicious tomatoes to use in summer recipes with your homegrown basil all summer long.

Best Growing Conditions for Tomatoes

Tomatoes need bright, full sun to grow—at least six hours of sunlight per day, and ideally eight or more. Keep this in mind when deciding where to site your tomato plants. 

They also need warm temperatures. Tomatoes do best with night temperatures in the range of 60 to 70 degrees and daytime temperatures between 70 and 85 degrees. They can be damaged by night temperatures lower than 50 degrees.

Use a rich, well-draining soil blend formulated for growing vegetables in containers. You can also make your own container mix by combining equal portions of compost, loamy soil, perlite, and peat moss. 

How to Care for Your Tomato Plants

Consistent watering is key to growing tomatoes successfully. Check the soil daily and water to keep it consistently moist, but not soggy. Water the soil directly, as getting water on the leaves can lead to diseases, and avoid overwatering, which can lead to root rot.

Position multiple plants with at least a foot of space between them so that the leaves don’t touch and there is plenty of airflow around the plants at maturity. After transplanting seedlings into large containers, install stakes or tomato cages around the plant to support it as it grows larger. 

Because tomatoes are heavy feeders, they will need to be fertilized to grow strong and produce healthy fruit. Feed your tomato plants with an organic liquid fertilizer made from seaweed or fish emulsion diluted to half-strength every one to two weeks.  

How to Propagate Tomato Plants

Tomatoes are annuals, meaning that they must be regrown each year. Start your tomatoes indoors six to eight weeks before the average last frost date for your region so that they are ready to transplant outdoors as soon as temperatures are warm enough. 

To propagate your own tomatoes, you’ll need seeds, a seed-starting medium, seed trays, small containers, and a container soil blend formulated for growing vegetables. For best results, use grow lights and a warming mat for seedlings. Once you’re ready to transplant your seedlings into containers, you’ll need five-gallon pots and an additional container mix. 

Step 1: Fill the cells of the seed trays with the seed starting mix, then water lightly until the mix is moist. Make a quarter-inch divot in each cell of the seed tray with the tip of your finger.

Step 2: Place a seed in each divot, then gently cover the seed with a quarter-inch of soil. Spritz the soil with water using a spray bottle until it’s well moistened if needed, taking care not to disturb the seeds.

Step 3: Put the seed trays in a warm, sunny place. You can use a seed starting mat under the tray to keep the seedlings warm if your space is cool. Check daily to ensure that the soil is moist, but not soggy, and water as needed. Sprouts should emerge within five to 10 days of planting.

Step 4: When seedlings emerge, do your best to simulate ideal outdoor growing conditions. That means keeping the seedlings warm, giving them full sun or using grow lights to give them enough light, and helping to strengthen their stems by simulating wind. To do this, position a fan near your seedlings and run it for an hour or so each day.

Step 5: When your tomato plants grow their true leaves—which will look like tiny mature tomato leaves with serrated edges rather than their first smooth, round leaves or cotyledons—you can begin to fertilize them. Feed seedlings once per week with an organic liquid fertilizer designed for vegetables that have been diluted to half-strength. 

Step 6: Your seedlings are ready to be potted up into small plant containers when they have a few sets of true leaves and are around three inches tall. Fill the containers with vegetable container soil mix and transplant the seedlings into the new pots, taking care to fill the pots with soil slightly higher on the stems than the soil level in the seed trays. This will help your tomatoes grow additional roots along the stem. Pat the soil gently around the base of the plant. 

Step 7: Before transplanting your seedlings into five-gallon containers that will live outdoors on your patio or deck, it’s important to harden off your seedlings, or acclimate them to being outside. Be sure to wait to do this until the last frost date for your region has passed. Start by putting your seedlings in a spot outdoors with part shade for a few hours before bringing them back inside, gradually increasing the duration and light each day over the course of a week or so. 

Step 8: Choose a cool, overcast day to transplant your seedlings into the large containers in which they’ll mature. Fill the containers with soil mix, then plant the seedlings so that the soil level comes up to just beneath the lowest set of leaves. Gently press the soil around the base of the plant. Keep it in a place with full sun. Check the soil daily and water to keep the soil moist, but not soggy.