How to Plant Tomato Plants in Ground: Step-by-Step Guide

Plant tomato plants in the ground after your last frost date when soil temperature reaches 60°F (15.5°C). Dig a hole deep enough to bury 2/3 of the stem, spacing plants 24-36 inches apart depending on variety. Add compost and balanced fertilizer to the planting hole, water deeply after planting, and apply mulch to retain moisture. This technique encourages stronger root systems and higher yields.

Ready to grow your best tomato harvest? Whether you're a first-time gardener or looking to refine your technique, this guide delivers exactly what you need to successfully plant tomato plants directly in the ground. Forget confusing advice—here's the proven method that delivers robust plants and abundant harvests.

Why Proper Planting Technique Matters for Tomatoes

Tomatoes aren't just another garden vegetable—they're heavy feeders that demand specific planting conditions to thrive. Unlike most plants, tomatoes actually benefit from being planted deeper than their nursery containers. This unique characteristic allows them to develop extensive root systems along the buried stem, creating stronger, more resilient plants that produce higher yields throughout the growing season.

According to research from the University of Illinois Extension, properly planted tomatoes develop up to 40% more root mass than shallow-planted counterparts, directly translating to better drought tolerance and increased fruit production. This biological advantage makes correct planting depth the single most important factor in your tomato growing success.

Pre-Planting Preparation: Setting the Stage for Success

Timing Your Planting Perfectly

Planting too early risks frost damage, while planting too late reduces your harvest window. The optimal planting window depends on your USDA hardiness zone:

USDA Hardiness Zone	Last Frost Date	Soil Temperature Target	Recommended Planting Window
3-4	May 15-30	60°F (15.5°C)	Early to mid-June
5-6	May 1-15	60°F (15.5°C)	Late May to early June
7-8	April 15-30	60°F (15.5°C)	Mid to late May
9-10	March 15-31	60°F (15.5°C)	Early to mid-April

Source: USDA Plant Hardiness Zone Map

Remember that soil temperature matters more than calendar dates. Use a soil thermometer to verify conditions—tomato roots won't develop properly in soil below 55°F (12.8°C). Morning planting on overcast days reduces transplant shock compared to planting in direct afternoon sun.

Soil Preparation Essentials

Tomatoes thrive in well-draining soil rich in organic matter. Two weeks before planting:

• Test your soil pH (ideal range: 6.2-6.8)
• Amend with 3-4 inches of compost worked into the top 12 inches of soil
• Add balanced organic fertilizer (5-5-5 or similar) according to package directions
• Create raised beds 6-8 inches high if drainage is poor

Avoid fresh manure which can burn roots—well-composted manure applied at least 30 days before planting is acceptable. The Cornell University Gardeners' Resource emphasizes that proper soil preparation accounts for 70% of your eventual harvest success.

The Step-by-Step Planting Process

Step 1: Prepare Your Seedlings

Before planting, harden off seedlings for 7-10 days by gradually exposing them to outdoor conditions. On planting day:

• Water seedlings thoroughly 1-2 hours before transplanting
• Gently remove from containers without disturbing roots
• Prune lower leaves that will be buried
• For leggy plants, remove all leaves except top 4-6 sets

Step 2: Dig the Perfect Planting Hole

Contrary to most plants, tomato planting holes should be deep, not wide:

• Dig hole 12-18 inches deep (depending on plant size)
• Make hole width only slightly larger than root ball
• Add 1 tablespoon of balanced fertilizer to bottom of hole
• Mix in 1/2 cup of crushed eggshells for calcium
• Create small mound in center of hole for roots to spread over

Step 3: Plant at the Optimal Depth

This is the critical step that determines your plant's future strength:

• Place plant in hole with only top 1/3 exposed
• Bury stem up to first set of healthy leaves
• Fill hole with amended soil, firming gently
• Create slight depression around plant for water collection
• Apply 2-3 inches of organic mulch, keeping away from stem

Research from the University of California Agriculture and Natural Resources shows that deep planting increases root development by activating adventitious root-forming cells along the stem. This creates a more extensive root system that accesses nutrients and water more efficiently throughout the growing season.

Step 4: Watering and Initial Care

Proper watering immediately after planting establishes roots:

• Water deeply with 1-2 gallons per plant
• Avoid wetting foliage to prevent disease
• Water daily for first week, then 2-3 times weekly
• Apply liquid seaweed solution for transplant shock reduction
• Install supports immediately to avoid root disturbance later

Spacing Requirements by Tomato Type

Proper spacing prevents disease and maximizes yield. Many gardeners make the mistake of planting too close together, which creates humidity pockets that encourage fungal diseases.

Tomato Type	Spacing Between Plants	Spacing Between Rows	Special Considerations
Determinate (Bush)	24-36 inches	36-48 inches	Requires less support; compact growth habit
Indeterminate (Vining)	36-48 inches	48-60 inches	Needs strong vertical support; continuous growth
Dwarf Varieties	18-24 inches	30-36 inches	Suitable for containers; limited spread
Cherry Tomatoes	24-36 inches	36-48 inches	Higher density possible with pruning

Source: University of Illinois Extension

Common Planting Mistakes to Avoid

Even experienced gardeners make these critical errors that reduce yields:

• Planting too shallow - prevents development of additional roots along the stem
• Over-fertilizing at planting - burns tender roots; wait 2-3 weeks for additional feeding
• Ignoring soil temperature - planting in cold soil stunts growth for weeks
• Watering incorrectly - inconsistent watering causes blossom end rot
• Planting in same spot yearly - increases disease risk; rotate crops annually

A survey of 500 home gardeners by the National Gardening Association revealed that 68% of tomato planting failures resulted from improper depth or spacing. The most successful gardeners (those harvesting more than 20 pounds per plant) consistently followed deep planting techniques and maintained proper spacing.

Troubleshooting Early Growth Problems

Watch for these common issues in the first 2-3 weeks after planting:

• Wilting after planting: Normal for 24-48 hours; water deeply if persists
• Yellowing lower leaves: Often normal as plant redirects energy; remove if severe
• Purple leaf tint: Indicates phosphorus deficiency; apply bone meal solution
• Stunted growth: Check soil temperature; may need black plastic mulch to warm soil
• Cracked stems: Sign of wind damage; provide temporary windbreak

Remember that tomatoes grow slowly for the first 2-3 weeks as they establish root systems—don't be concerned if visible growth seems minimal initially. The University of Florida's Institute of Food and Agricultural Sciences notes that patience during this establishment phase pays off with stronger plants later in the season.

When NOT to Plant Tomatoes Directly in the Ground

While planting in the ground generally produces the best results, certain conditions warrant alternative approaches:

• Soil remains consistently below 55°F (12.8°C)
• Heavy clay soil that doesn't drain well
• Short growing seasons with less than 60 frost-free days
• Areas with severe soil-borne diseases like fusarium wilt
• Urban environments with contaminated soil (lead, chemicals)

In these situations, consider container gardening or raised beds with imported soil. The USDA Natural Resources Conservation Service recommends soil testing in problematic areas before committing to in-ground planting.

Final Tips for Maximum Tomato Success

Implement these professional techniques for exceptional results:

• Plant in the evening or on cloudy days to reduce transplant shock
• Add mycorrhizal fungi to planting holes to enhance root absorption
• Use red plastic mulch to increase yields by up to 20% (proven by USDA studies)
• Apply aspirin solution (1 crushed aspirin per gallon of water) to reduce stress
• Pinch off early flowers to direct energy to root development

By following these evidence-based planting techniques, you'll establish a strong foundation for a bountiful tomato harvest. Remember that the first few weeks after planting determine your entire season's success—invest the time to get it right, and you'll reap the rewards all summer long.

How deep should I plant tomato plants in the ground?

Plant tomatoes deep enough to bury 2/3 of the stem, leaving only the top 1/3 with leaves exposed. For most seedlings, this means digging a hole 12-18 inches deep. This deep planting technique activates additional root growth along the buried stem, creating a stronger, more productive plant.

What's the best time of day to plant tomatoes?

The best time to plant tomatoes is in the late afternoon or on overcast days. This gives plants several hours of cooler temperatures and reduced sunlight to establish roots before facing full sun. Morning planting is acceptable if followed by immediate watering and temporary shade protection. Avoid planting during the heat of the day, which increases transplant shock.

How far apart should tomato plants be spaced?

Spacing depends on tomato type: determinate varieties need 24-36 inches between plants, while indeterminate varieties require 36-48 inches. Rows should be spaced 36-60 inches apart depending on variety. Proper spacing ensures adequate air circulation, reduces disease risk, and allows each plant to receive sufficient sunlight for maximum production.

Should I remove leaves when planting tomatoes?

Yes, remove all leaves that would be buried below soil level. For leggy seedlings, you can remove all leaves except the top 4-6 sets. This prevents buried leaves from rotting and redirects the plant's energy to root development. However, don't remove healthy leaves above soil level, as they provide essential energy through photosynthesis during establishment.

How much water do newly planted tomatoes need?

Water newly planted tomatoes deeply with 1-2 gallons per plant immediately after planting. For the first week, water daily to keep soil consistently moist but not soggy. After the first week, reduce to 2-3 times weekly with deeper watering sessions. Always water at the base of the plant, avoiding the foliage, to prevent disease. Consistent moisture is critical to prevent blossom end rot later in the season.