Grafted Tomato Trials Set to Begin

comments (6) May 22nd, 2013

Pin It

WesternGardener Jodi Torpey, contributor
thumbs up 15 users recommend

Three varieties of grafted and non-grafted tomatoes will be planted side-by-side and then evaluated as part of the Harris Seeds Home Garden Trials for 2013.Click To Enlarge

Three varieties of grafted and non-grafted tomatoes will be planted side-by-side and then evaluated as part of the Harris Seeds Home Garden Trials for 2013.


The Harris Seeds Home Garden Trials for 2013 are set to begin. I'm just waiting for the night-time temperature to get to a predictable 55 degrees and then I can start planting.

This is my second year to be invited to be part of the company's trialing program. In addition to testing several varieties of flowers, peppers and tomatoes, Harris Seeds is interested in evaluating three varieties of grafted heirloom tomatoes.

Grafted vegetables are working their way onto the pages of seed catalogs and into neighborhood nurseries and garden centers. By grafting a tasty, heirloom tomato onto a tougher rootstock, the plants grow to be stronger and more resistant to soil-borne diseases and stressful growing conditions.

The results of this trial will help Harris Seeds decide which varieties the company will consider adding to its catalog in the future.

The trial tomato sampler includes grafted and non-grafted Pink Brandywine, Cherokee Purple and San Marzano tomatoes for a side-by-side comparison. 

I've already reported on how the plants looked when they arrived. Because this is a trial program, Harris Seeds wanted feedback on plant quality (leaf color, stem quality and general vigor); shipping quality (plant damage or dislodging from cells); and whether a printed planting guide and plant identification legend were included.

Planting information is always important, but it's especially essential for grafted plants. The graft needs to be planted at least one inch above the soil line. If the graft is planted below the soil line, the grafted (scion) plant will begin to root in the soil. This means the plant will bypass its grafted rootstock, which defeats the purpose of having a grafted plant.

The planting guide gives step-by-step instructions for choosing the right planting location, preparing the soil, mulching and watering. Care after planting includes keeping the plants consistently moist, fertilizing every 2-4 weeks, protecting them from frost and adding tomato supports or cages.

All of the care instructions are meant to help get the best results during the testing process.

Later this season I'll report my results. The grafted tomato evaluation asks gardeners to rate transplant quality, plant vigor, disease resistance, weather tolerance, and yield. The tomatoes will be rated on taste (flavor, texture, aroma and culinary appeal) and quality (appearance, consistency and uniformity).

If non-grafted plants are grown alongside the grafted heirloom tomatoes, gardeners are asked to evaluate any visible difference in plant vigor, yield and disease resistance.

Because grafted tomatoes are more costly to produce, there are also questions about pricing and whether grafted tomatoes are worth the added expense. 

I'm looking forward to being part of the home garden trials and to sharing some of my experience with you during the season and after the harvest.

Have you grown grafted tomatoes in your garden? If so, please share comments about your experience (positive or negative).


After you try it, show it off to other members in the
gardener's gallery.
Post your photos

posted in: tomatoes, grafted tomatoes

Comments (6)

Fantyholmer writes: well done
Posted: 12:48 am on October 26th
JoantheGardener writes: I grew 75 plants this year. 26 Grafted, 42 Ungrafted, and 7 volunteers. I purchased my grafted plants from Garden Life, Burpee, Hirt's, and Territorial Seed. My ungrafted plants came from a variety of sources; on line, nurseries or garden centers, seeds from a variety of sources, or seeds I had saved. 78% of the ungrafted plants had average to very high yields as compared to the grafted plants which was around 65% average to very high. However, only 23% of the grafted plants had very high yields compared to 48% of ungrafted varieties. I did not grow the same variety of grafted vs. ungrafted side by side. However, it seems that the smaller fruited varieties (salad/paste size or smaller) did the best as grafted plants. Sadly, the large fruited varieties did avg to poor and many of those were still susceptible to leaf diseases which a robust rootstock won't fix. I have had success using Actinovate when I plant to help control these. Just need to make sure you use de-chlorinated water when you mix it up. Overall, this year I had the biggest crop of beautiful tomatoes I've ever had. I have raised beds and planters that I amend with compost and worm castings every year. Organic Fertilizer (Bob's and/or Dr Earth) at planting time. Then just sunshine and water. No pesticides. The clear winner for sheer size and numbers: Bill's Big from Lazy Ox Farm, followed by Super Fantastic (about 60 pounds from one plant) and Carmello (also another 60 pounds). Interested to see your results...
Posted: 4:30 pm on September 12th
bruceden writes: So far my grafted tomatoes are diseased and not producing very well
Posted: 5:58 pm on July 15th
WesternGardener writes: Thanks for your comments--it's always interesting to hear what's going on in other gardens.

When planting grafted tomatoes, prepare the planting hole just deep enough to cover the root ball, and be sure to keep the graft at least 1" above the soil line. Water plants in. You might also add some diluted liquid fertilizer to help the plants handle transplant shock. Just like with other tomato plants, support with stakes or cages.

With proper care through the season, the grafted tomatoes should really produce for all of us!

--Jodi
Posted: 1:53 pm on May 23rd
braggo writes: I too am trying out some grafted heirloom varieties this year. I ordered mine from Burpee, although it looks like they came from a 3rd party via Burpee. As mentioned above, the instructions stated to keep the graft point above ground level. It looks like I may have to add some vertical support in addition to the tomato cage. Hopefully they will produce well and stay healthy.
Posted: 10:46 am on May 23rd
brianrmacdonald writes: I tried grafted tomatoes last year. They were not successful for me. The yield I got was about the same or maybe even a bit less than I have gotten with ungrafted tomatoes. I don't have a lot of trouble with diseases so I can't really comment on that aspect. I got my grafted tomatoes from a mail order place. The graft was right at the soil line and the instructions that came with them instructed me not to bury the graft (i.e. avoid giving the scion a chance to grow roots). As a result the root ball I got with the grafted tomatoes was not any bigger than I am able to produce by trenching ungrafted tomatoes. Maybe grafting would be more successful if the scion was grafted higher on the plant so that the rootstock could be treated in such a way to grow more roots.

Good luck with your trials. I'll be interested to see your results.
Posted: 8:39 am on May 23rd
Log in or create a free account to post a comment.