Tomato Grafting: How to Grow Disease-Proof Heirloom Tomatoes

Heirloom Tomatoes Grafting Guide (Pictured: Persimmon, Grape, Garden Peach, Black Prince) by Tyrant Farms
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Easily Grow the Best Tomatoes You’ll Ever Taste

We live in the southeast, a region of the country whose once-fertile topsoil has largely been stripped bare by centuries of poor land management practices ranging from deforestation to chemical mono-crop/industrial agriculture.

Industrial agriculture (

This is not a healthy ecosystem with living dirt, it’s a broken one (courtesy of industrial agriculture).

As such, the soil in our area is pretty difficult to work with. Like most local gardeners and farmers we know, we started with highly acidic, compacted red clay that is better suited for making bricks than growing food. What to do?

We’re strong proponents of “restoration agriculture” or “permaculture.” These are food-growing philosophies that go beyond sustainability (after all, sustainability only makes sense if you’re starting with a healthy ecosystem, not a heavily damaged one like we have in 2013). Permaculture aims to restore the “soil food web” and the entire ecosystem around it while growing healthy, organic foods that feed all participants (people included).

Without healthy soil, it is impossible to grow food that isn’t doused in poison, drenched in synthetic fertilizer or genetically modified. A single teaspoon of healthy soil can have upwards of 4 billion microorganisms—each of which plays a unique role in the soil’s continued health—whereas a comparable teaspoon of soil from a plowed, poisoned piece of land under industrial agriculture will have almost no microbial life at all (or intrinsic nutrient density).

Over the past three years, we’ve seen ourselves as “dirt doctors” and have been treating our soil web with lots of natural medicines: wood chips, compost, leaf mold, nutrient-accumulating plants, etc. It’s been a wonderfully rewarding and educational experience observing nature work its magic in tune with our feeble wand.

What was once dead, brick-hard clay is increasingly becoming rich, black soil that is teeming with worms and microbial organisms. Pollinators are buzzing about everywhere. Wasps, mantises, lady bugs, lace wings and multiple species of insect-munching birds are constantly on the prowl helping us with pest control.

Our soil is becoming healthy again and helping us be healthy too!

Be Smart Enough To Know That Nature Is Smarter Than You

We know that we’re not very smart; certainly not smart enough to try to outsmart or fight against nature in order to grow food. However, we are smart enough to know that nature is a lot smarter than we are and that our garden will produce better results if we create systems that mimic, rather than fight, nature. We hope that more people around the globe will begin to humble themselves to this reality for the sake of all current and future life on earth.

*If you’re a relatively new gardener and you’re feeling overwhelmed, we’d suggest having a read of our blog post: Top 10 Steps to Starting Your Garden before someone tries to load up your shopping cart with a bunch of chemical fertilizers and poisons.

The Modern Tomato 

As this shocking NPR interview of the author of TomatoLand outlines, most tomatoes that you’ll find on a modern grocery store shelf or restaurant are hybrid varieties bred to: 1) be disease-resistant, 2) produce indestructible fruit that lasts forever, and 3) be visually appealing (big, round and red). Notice that “better flavor” was not included in that top-3 list of priorities.

Most of these tomatoes are grown via industrial monoculture in Florida in nutrient-free sand that thus requires heavy fertilizer and pesticide application. Throughout the growing season, the tomatoes are sprayed with poison cocktails that include about 150 different types of highly toxic pesticides. Next, they’re picked (while still unripe and green) by modern day slaves who are also doused in pesticides before being locked back in their pens (for which they’re charged rent by their masters). Then the tomatoes are put on the road to where you can happily buy them (grocery store, restaurant, etc). Finally, they’re sprayed with Ethelyene gas which causes them to turn red very quickly, even though they aren’t technically ripe, since they need to be able to firm enough to cut into thin slices for your burger or last for month on a shelf.

Industrial tomato farm, photo courtesy of

Industrial tomato farm in Florida, photo courtesy of

We have vivid imaginations, but we could never dream up a more criminal, inhumane, poorly designed, rapacious system than the one we use in the US to grow the vast majority of our tomatoes (and other crops too).

So, what if your tomatoes are covered in poison, picked by slaves and taste like cardboard? They’re cheap, right? And that’s the only thing that matters! Our market economy is simply doing what us consumers tell it to do. Maybe.

If the markets are just responding to our demands, maybe we should tell the market this is NOT what we want.

What Are Heirloom Tomatoes & Why Should You Grow Them?

Heirloom tomatoes are “antique” varieties of tomatoes, some of which date back many hundreds of years. They’re renown for their rich, distinct flavors and a wide variety of shapes, colors and sizes. People who’ve eaten their first sun-ripened heirloom tomato directly off of a plant at Tyrant Farms have remarked that they “never knew that tomatoes could taste this good.”

Heirloom tomatoes (black prince and persimmon tomatoes with thai and purple basil) at Tyrant Farms.

An heirloom tomato snack (black prince and persimmon tomatoes with thai and purple basil) at Tyrant Farms. Yum!

Are you anti-slavery, anti-eating toxic chemicals, pro-taste and pro-not-burning-down-the-house-you-live-in? Cool, so are we! Get yourself some heirloom tomato seeds and start growing your own asap. You can easily save enough seeds each year to grow them again and share the surplus with everyone you know.

The Challenge of Growing Heirloom Tomatoes

When your dirt is unhealthy (which almost all soil in the US and around the globe is at this point), your plants will be unhealthy too. Heirloom tomatoes were originally cultivated in times when various plant diseases were not nearly as prevalent as they are today, so they’re relatively susceptible to plant diseases.

At Tyrant Farms, we’ve had seemingly healthy plants wilt and die virtually overnight from fusarium wilt and verticillium wilt. As you might imagine, it’s downright heart-breaking seeing a plant you’ve grown from seed that is covered with unripe tomatoes suddenly perish.

So, unless you have very healthy soil, there’s a good chance you’ll lose a lot of your heirloom tomatoes to disease. Beyond working with nature to improve the long-term health of your soil (which you should do anyway), what can you do if you want to grow healthy heirloom tomatoes?

Growing 100% Disease Resistant Heirloom Tomatoes Via Grafting

Plant grafting is an ancient technique that likely dates back at least 3,000 years. Nearly all apples, peaches, pears, plums and similar fruits that we enjoy today are grown using plant grafting, wherein a cutting of a desired plant lineage is grafted atop a hardy rootstock.

grafted cherry - craigs crimson -

A grafted Craig’s Crimson cherry at Tyrant Farms (the graft line is clearly visible a few inches above the ground).

Can you graft tomato plants too? Heck yeah! This is our first year giving it a shot, but it’s pretty easy to do and produces extremely vigorous, disease-resistant heirloom tomatoes plants that are also genetically pure (you can save the seeds without concern).

How to Graft Heirloom Tomato Plants

There are three basic methods that can be utilized to grow grafted heirloom tomatoes:

  1. Approach Grafting
  2. Cleft Grafting
  3. Tube Grafting

After reviewing the nuts & bolts of all three methods, we decided on Cleft Grafting, since it seemed to be the easiest method requiring the least amount of purchased materials. Since Cleft Grafting is the only tomato grafting method we have experience with, that’s what we focus on below (*we did try grafting a couple of tomatoes using Approach Grafting and they all died—this was probably due to our incompetence, not due to any fault inherent to the method itself).

Step By Step: Cleft Grafting Heirloom Tomatoes

Cleft Grafting requires slightly larger tomato plants than the other two grafting methods (plant stalks about 1/4 to 1/2 inch in diameter). You’ll need one disease resistant hybrid tomato plant and one heirloom tomato plant for each grafted plant you intend to grow. For our hybrid root stock, we’re experimenting with Colossus, Celebrity, Big Beef and Mountain Magic, all of which seem to work very well.

Materials you’ll need:

  • Razor blades (or box cutter),
  • Rubbing alcohol in small bowl (to clean the blades before and after cutting each plant),
  • Parafilm grafting tape to secure and hold the heirloom plant top to the hybrid root stock base,
  • Small planters for each newly grafted plant,
  • Spray bottle/mister.


  1. Sow Seeds – Put your hybrid rootstock seeds into small containers about 1 week before you sow your heirloom tomato seeds (the hybrid root stock plants must be at least the same size if not larger than the heirloom stalks you’ll eventually be grafting onto them).
  2. Match an Hybrid to an Heirloom to Graft – After the plants have produced at least 5 leaves or grown to be 1/4 – 1/2″ thick, pick out a hybrid and an heirloom to graft together. Again, it’s important that the hybrid base be AT LEAST as thick if not thicker than the heirloom shoot you’ll place on it. 
  3. Hybrid Surgery: Wedge Opening – At first, it feels really strange to decapitate perfectly healthy tomato plants, but you’ll get used to it! Cut the hybrid plant between 2″ and 4″ above the dirt line (straight cut parallel to the ground). Remove any remaining leaves on the hybrid based, then cut your “wedge opening.” The wedge opening is a single cut straight down the center of the hybrid stem. You’ll be putting your heirloom stalk in the opening shortly.
    Grafting Heirloom Tomatoes - Slice Rootstock with Blade (
  4. Heirloom Surgery: Wedge – Cut your heirloom plant off of its base parallel to the ground, approximately 2-4″ above ground level. Next, carefully cut an heirloom “wedge” by cutting both sides of the heirloom stalk into a V-shape to fit into the hybrid plant base’s “wedge opening.” Remove all but the top scion leaves on the heirloom stalk so the plant can put it’s energy into rooting/grafting rather than maintaining its leaves. Grafting Heirloom Tomatoes - Cut Scion to A Wedge (
  5. Join & Tape the Plants – “And the two become one…” Firmly insert your heirloom wedge into your hybrid wedge opening making sure that at least one side of the outside edge (cambium layer) of the scion is lined up with the outside edge of the rootstock so as to ensure good “blood flow” between the two plants. Cut a small piece of parafilm off your roll, and stretch it out (not too thick, about 3″ of tape AFTER it’s been stretched so the plant can break out of it when ready). Wrap the strip of stretched parafilm tape around the grafted area. Some people use grafting clips instead of parafilm tape, but we like tape better since the plant tells you when it’s ready by breaking out of the parafilm tape rather than you guessing when it’s time to remove the clip.
    Grafting Heirloom Tomatoes - Scion into Rootstock (
    Grafting heirloom tomatoes - Parafilm scion to roostock attachment (
  6. Days 1-3: Cover In a Dark Spot & Spray – Your freshly grafted tomatoes are going to need a lot of loving. They need to be in a humid, dark place (bathtub, garage or outside shed) completely out of the sun. We put ours under plastic storage bins in our garage during this step. Keep them very wet for the next three days, using a spray bottle several times per day to spray down the stem, foliage and keep the roots moist. It’s difficult to overmist during this step (*we tried to time Days 1-3 during a time when the weather forecast called for several days of rain to help with humidity levels). You may lose a few plants between Day 1 and Day 10, so don’t beat yourself up! The more you graft, the better you’ll get at it and the less plants you’ll lose.      
  7. Days 4-7: Shade – Bring your grafted tomatoes out from the dark, but make sure they’re in a shady spot, watering often until around day 7. If they seem like they’re going strong, try moving them into partial sun but keep an eye on them to make sure they don’t look wilted or stressed.  
  8. Days 7-10: Sun – Bring them into full sun and keep an eye on them. Keep moist and water any time they look wilted or stressed. 
  9. Day 10: Plant – Put your grafted heirlooms into the ground in a full sun spot. Make sure that your graft line is NOT below the surface of the soil, since this will make the heirloom susceptible to whatever diseases are in your soil. 
  10. Eat & Share – Your grafted heirloom tomatoes should be extremely vigorous and produce an abundance of fruit throughout the season (yep, tomatoes are a fruit). These fruit will be genetically pure to their lineage, so make sure to save some seeds for the future. Share your tomatoes, seeds and your gardening knowledge with everyone you know!
    Grafting heirloom tomatoes - healed graft (


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