5 tips for planting tomatoes to help ensure a bumper harvest

Growing tomatoes can be rewarding, but getting that bumper harvest requires a bit of know-how.

These five quick tips on planting tomatoes are backed by research and will help you maximise your tomato yield and grow healthier, more productive plants.

1: Plant Tomatoes Deep and Sideways

Unlike most garden plants, tomatoes have the unique ability to grow roots along their stems. Taking advantage of this superpower is the key to developing stronger plants that produce more fruit.

When planting tomatoes (i.e your tomato seedlings), remove the lower leaves and bury at least two-thirds of the stem. This means that the plant develops more feeder roots, which enable it to draw in more water and nutrients and, thus, grow more strongly

You can also try the sideways planting method: dig a trench about 4-6 inches deep, lay the tomato plant sideways in the trench with the top portion gently curved upward, and cover the stem with soil, leaving only the top few sets of leaves exposed.

This sideways planting technique encourages even more root development along the buried stem, creating a stronger foundation for your plant.

Research from Cornell and Clemson universities shows that tomatoes grown using deep or sideways planting have higher yields, stronger stems, and ripen earlier due to their expanded root systems (Harvest Savvy, 2025).

According to Rural Sprout, “burying tomatoes deeply will give you all the advantages of adventitious root growth” (Rural Sprout, 2024).

More roots mean better nutrient absorption, improved drought resistance, and ultimately, more tomatoes!

Tip 2: Add Calcium at Planting Time. Or is This a Myth?

Blossom end rot—that disappointing black spot on the bottom of tomatoes—is often caused by calcium deficiency. However, research from Mississippi State University Extension reveals this deficiency is typically caused by uneven water availability rather than a lack of calcium in the soil. As they explain, “Blossom end rot is a calcium deficiency, but that deficiency is normally caused by uneven water availability to the plant” (Mississippi State University Extension, 2023).

While adding calcium at planting time won’t hurt, the most critical factor is consistent watering. According to the Old Farmer’s Almanac, “Wide fluctuations in soil moisture reduce the plant’s ability to take up calcium from the soil” (The Old Farmer’s Almanac, 2024). When calcium is deficient during early fruit development, cell wall membranes collapse, causing those dark, sunken pits at the bottom of the fruit.

If you want to add calcium anyway, incorporate bone meal or garden lime, which scientific studies have found are more effective than eggshells at providing immediately available calcium (The Scientific Gardener, 2023).

Tip 3: Bury Boosters in the Planting Hole

Give your tomatoes a head start by adding these scientifically-supported items to the planting hole:

• A handful of compost for slow-release nutrients
• 2-3 crushed aspirin tablets to boost the plant’s natural immune system – Research from the USDA found that salicylic acid (the active ingredient in aspirin) produces an enhanced immune response in plants of the nightshade family, helping them fight off diseases (Gardening Know How, 2021). The Rusted Garden explains that “the salicylic acid in the aspirin will trigger the tomato’s defenses, by mimicking the natural hormone, as if it were being attacked” (The Rusted Garden, 2023).
• A fish head or a few fish scraps for nitrogen and trace minerals – Fish provides all three essential nutrients for plant growth (nitrogen, phosphorus, and potassium), plus important trace minerals like calcium and magnesium (Rural Sprout, 2023). As Rural Sprout notes, “by burying a fish beneath your tomato at the beginning of the season, you are essentially ‘planting’ a slow-release fertilizer” that feeds the plant all season.
• A few crushed dried banana peels for potassium
• A sprinkle of Epsom salts for magnesium, which promotes sweeter fruits

These additions create a time-release nutrient package that will feed your plants throughout the growing season. While not all of these methods have undergone rigorous scientific testing, many experienced gardeners have found success with these techniques, particularly the aspirin and fish head methods.

Tip 4: Use Proper Spacing and Pruning Techniques

Proper spacing is crucial for maximizing your tomato harvest. Plant determinate varieties (bush types) about 2 feet apart and indeterminate varieties (vining types) about 3-4 feet apart.

For indeterminate varieties, remove suckers (or sideshoots) — the small shoots that form in the crotch between the main stem and branches—to direct the plant’s energy toward fruit production rather than excessive foliage. However, you can leave a few suckers on the lower part of the plant to increase yield.

Tip 5: Create a Heat-Reflecting Mulch System

Tomatoes love heat, and you can boost your harvest by increasing soil temperature. After the soil has warmed up in late spring:

1. Lay down red plastic mulch around your plants—studies by Penn State University show “tomato yields have been as much as 20% higher with red plastic mulch than with black mulch” (Grower’s Solution, 2024). Red mulch reflects intensified red light to the developing plants, which increases their photosynthetic capacity.
2. According to USDA research, “the red mulch reflects wavelengths of light that cause the plant to keep more growth above ground, which results in greater yield,” while putting less energy into the root system (Agricultural Research Magazine, 1997). In field tests, plants grown with red plastic mulch produced significantly more tomatoes than those with black plastic mulch.
3. Cover the plastic with a thin layer of organic mulch like straw to prevent overheating.

This technique reflects heat and light back to the plants, accelerating growth and ripening while conserving soil moisture. However, Cedar Circle Farm notes that “studies of red mulch have not shown consistent results nor do farmers have a consistent opinion. Red mulch sometimes increases yield of tomatoes, but not always. Different tomato varieties also appear to respond differently to the red mulch” (Cedar Circle Farm, 2024).

By implementing these five planting hacks, you’ll be well on your way to growing stronger tomato plants that produce an abundant harvest. Remember that proper care after planting—consistent watering, regular feeding, and good pest management—will help your plants reach their full potential.