How Deep Should Tomatoes be Planted?

Forget everything you’ve been told about shallow planting – when it comes to tomatoes, you should bury a full 2/3 of your plant underground. That’s right, if you’ve got a 12-inch tall seedling, only the top 4 inches should peek above the soil surface.

Sound crazy? This counterintuitive technique will revolutionize your tomato harvest by creating an incredibly robust root system that translates directly into bigger, better fruit.

We know, we know. This flies in the face of every gardening rule you’ve ever heard about “don’t bury the stem, or you’ll kill your plants.”

But here’s the thing – tomatoes are special. Unlike most garden plants, tomatoes possess a remarkable ability to develop adventitious roots along any buried portion of their stems. These aren’t just extra roots; they’re your ticket to tomato success.

Why Deep Planting Works Like Magic

The science behind this technique is fascinating and proven. When you bury that stem deep, thousands of tiny root hairs emerge along the buried section, essentially giving your plant a supercharged root system that’s 3-4 times larger than conventional planting would provide.

This expanded root network means your plants can absorb more water and nutrients, support heavier fruit loads, and withstand summer heat stress that typically devastates shallow-rooted tomatoes (this technique works equally well whether you’re growing in garden beds, raised containers, or traditional in-ground plots).

Those extra roots also anchor your plants more securely, reducing the need for extensive staking and preventing the heartbreaking sight of loaded branches snapping under the weight of beautiful tomatoes. It’s like giving your plants a foundation upgrade from a tiny apartment to a sprawling mansion.

Here’s How to Plant Your Tomatoes Deep:

1. Start with premium soil preparation. For in-ground gardens, enrich your native soil by working in 2–3 inches of compost or high-quality garden soil like Miracle-Gro® Garden Soil for Vegetables and Herbs.
   
   Container gardeners should fill pots with lightweight, well-draining potting mix such as Miracle-Gro® Potting Mix. Raised bed growers need something in between – try Miracle-Gro® Raised Bed Soil for the perfect balance.
   
2. Measure and dig your hole. Calculate 2/3 the total height of your plant (including the root ball) and dig a hole that deep. For a 15-inch plant, you’ll need a 10-inch deep hole.
   
3. Optional stem preparation. You can pinch or snip off the lower branches that will be buried – this makes planting easier and prevents underground leaf decay, though it’s not absolutely necessary.
   
4. Remove your plant carefully. Gently squeeze the container sides and slide out your tomato. If it’s in a biodegradable peat pot, just remove the label and tear off the bottom rim.
   
5. Position your plant. Lower it into the hole so only the top 1/3 remains above ground. The buried portion should feel snug, but not compressed.
   
6. Try the trench method (alternative). Instead of a deep hole, dig a 6-inch deep trench and lay the plant on its side, angling the top growth upward. This works especially well in heavy clay soils.
   
7. Backfill gradually. Add soil around the buried stem, gently firming as you go. Water lightly during filling to eliminate air pockets.
   
8. Label your variety. Use plant markers to track which cultivar you’ve planted – you’ll thank yourself during harvest season.
   
9. Water thoroughly and establish feeding schedule. Give your newly planted tomato a deep drink, then continue watering when the top inch of soil feels dry. To avoid problems like blossom end rot and overwatering, check out Tomato Container Watering: Avoid Overwatering for specific schedules, signs to watch for, and troubleshooting tips.
   
   Feed every 2–3 weeks with calcium-rich plant food like Miracle-Gro® Shake ‘n Feed® Tomato, Fruit & Vegetable Plant Food to prevent blossom end rot and boost fruit production.

Buy Miracle-Gro Water Soluble Tomato Plant Food

Your Reward Awaits

Here’s the exciting part – within just 10–14 days, you’ll notice your plants looking more vigorous and sturdy than conventionally planted tomatoes.

By mid-summer, those super-roots will be supporting what can only be described as tomato trees, loaded with clusters of perfect fruit.

In just a couple of months or so, you’ll be harvesting a bountiful crop of gorgeous, full-flavored tomatoes that will make your neighbors wonder what secret you’ve discovered.

The best part? This technique works with every tomato variety, from tiny cherry types to massive beefsteak giants. Your plants will thank you for giving them the root space they’ve been craving all along.

Pro tip: When transplanting, choose the coolest part of the day (early morning or evening) to minimize transplant shock and give those new roots the best start possible.