Bury Your Tomatoes Deep. Like, Really Deep.

I killed a lot of tomatoes before I figured out I was planting them wrong. Not wrong like I forgot to water them. Wrong like I was leaving six inches of perfectly good stem above ground for no reason. Just vibes.

Turns out tomatoes are one of the few vegetables that actually want to be buried. Not just tucked in. Buried. That hairy stem? Every one of those tiny hairs is a root waiting to happen. Plant deep enough and you get a root system that makes a normal shallow-planted tomato look embarrassed.

What’s Actually Happening Down There

Tomato stems have adventitious roots, which is a fancy way of saying the stem will sprout roots wherever it touches moist soil. You can bury two-thirds of a leggy tomato transplant and in two weeks it’s basically a different plant underground. More roots means more water uptake, more nutrient access, and way more drought tolerance through our dry Redmond summers.

One sentence of science and we’re done. Promise.

How Deep Is Deep Enough

I aim to leave only the top 2 or 3 sets of leaves above soil. Everything below that gets buried. For a typical 6-inch transplant from starts at Lowe’s or Sky Nursery, that usually means digging down 8 to 10 inches. For a leggy indoor-started seedling that got a little too tall because you started it in February like I do, you might bury even more.

Two ways to do this. You can dig straight down and just drop the plant in. Or, if your soil is compacted or rocky (hi, Redmond clay), dig a shallow trench at an angle and lay the stem in horizontally, bending just the top few inches upward. The stem straightens itself out within a few days. Which sounds fake but isn’t.

Strip the Leaves First

Before you bury anything, pull off every leaf and branch that’s going underground. This is the part I forgot to do the first time. Buried leaves rot. Rotting leaves introduce disease right at the root zone, which is a spectacular way to ruin a plant that was just starting to feel good about itself.

Takes about 90 seconds per plant. Worth it every time.

This Is Extra Useful for Leggy Transplants

Here in the PNW, most of us are starting tomatoes indoors right now under lights, or we already did and things are getting a little tall and wobbly. That’s fine. Normal, even. Deep planting basically turns your mistake into a feature. The legginess that was embarrassing in the grow light setup becomes buried stem and new roots in the ground. Stems to the occasion, really.

I started mine under a LED grow light in late February and they’re already a bit stretched. Not panicking. They’re going in the ground deep and I’ll let the soil do the rest.

Warm the Soil Before You Plant

This matters more than people think. Tomatoes don’t love going into cold soil. Roots are slow to establish below about 60 degrees, and here in Redmond we usually don’t hit that reliably until mid to late May. Planting deep into 50-degree soil doesn’t help you much if root development stalls out anyway.

I use a cheap soil thermometer, paid $6.89 at the hardware store on Avondale, nothing fancy, to check before I commit. If you’re in a hurry, lay black plastic mulch or even a sheet of black garbage bag over the bed for a week or two. Warms the soil a few degrees. Free if you’ve already got one in the garage, which I did.

Does It Actually Work

Last year I planted two Sungold starts the same day. One went in at normal depth, one I buried down past the third leaf cluster. By mid-July the deep-planted one had noticeably more fruit. My oldest daughter pointed it out, which was annoying because I was going to point it out first.

Sample size of two is not a scientific study. I know. But it matched what I’ve seen over several seasons and it costs exactly nothing extra to do, so I’m not waiting for peer review.

Quick Recap Before You Go Dig a Hole

• Strip all leaves that will go underground
• Dig deep or trench at an angle for compacted soil
• Leave only 2 to 3 leaf sets above ground
• Wait until soil is at least 60 degrees before planting out
• Mulch after planting to hold moisture

That’s really it. No special product, no extra cost. Just a deeper hole and a little patience. You could say deep planting is the root of all tomato success. (I’m not sorry. Not even a little.)

Photo by Zoe Richardson on Unsplash