Growing Tomatoes in Mounds: A Step-by-Step Guide

Overview

Tomatoes are the most popular fruit grown in home gardens, prized for their robust flavor in salads, sandwiches, and sauces. While traditionally grown in rows with cages, planting tomatoes in mounds provides loose, well-drained soil that encourages vigorous growth and prolific fruit production.

Step 1: Test and Amend the Soil

Test your soil in fall or early spring to determine its nutrient needs and pH. Fall testing gives amendments time to break down before planting. Follow the test kit instructions to adjust the pH to 6.5–7.0 and balance nutrients.

Step 2: Prepare the Planting Site

Choose a location that receives full sun (6–8 hours daily). Till the soil to a depth of at least 8 inches, removing stones, roots, and weed debris. Rake the area smooth.

Step 3: Build the Mound

Rake soil into a broad mound 24–36 inches in diameter and 6–8 inches high.

Step 4: Warm the Soil with Plastic Mulch

Two weeks before planting, cover the mound with black or red plastic to warm the soil and suppress weeds. Punch holes every 6–8 inches to allow water penetration. Secure the edges with soil or stones.

Step 5: Plant After Frost Danger Passes

In spring, after the last frost, cut a large X in the center of the plastic.

Step 6: Plant Deep for Strong Roots

Dig deeply into the mound and set the seedling through the X so only the top 3–4 inches remain above ground. Roots will form along the buried stem, creating a robust root system. Firm the soil around the base and water deeply to saturate the root zone.

Step 7: Install Support

Place a wire tomato cage or tower over the seedling and push the legs firmly into the soil.

Step 8: Water Consistently

Water once or twice a week, applying enough to saturate the soil (2–3 gallons per plant per week depending on climate). Allow the soil to dry slightly between waterings.

Step 9: Fertilize for Fruit Production

Apply a foliar fertilizer formulated for tomatoes every 10–14 days throughout summer. Choose a product high in phosphorus to promote blooming, root development, and fruit set. Avoid high-nitrogen formulas, which encourage foliage at the expense of fruit.