Skip to content

Plant Profile: Marnero Tomatoes

Photo courtesy of Johnny's Selected Seeds

Photo courtesy of Johnny’s Selected Seeds

There is a new crop in town here in our company headquarter’s grow rooms, and we are very excited to share it. While it isn’t a new crop for everyone, it is the first time we have ever grown it here, and so far we like what we have seen from our Marnero Tomatoes. We haven’t even harvested our first tomato yet, but for horticulture fanatics like us, it’s been hard to keep this under wraps for so long. You can learn about caring for your own crop of young tomatoes in this month’s plant profile.

Marnero Tomatoes (F1 Hybrid) Solanum lycopersicum

Days to Bloom: 80

Disease Resistances

TOMV Tomato Mosaic Virus

F Fusarium Wilt (Race 1)

FOR Fusarium Crown and Root Rot

V Verticillium Wilt

Growing Method

With this being the first time we have ever grown this variety of tomato, we started our Marnero Tomatoes as seeds. We first placed each individual seed into its own Grodan A-OK 1.5” x 1.5” Starter Plug, and placed them into a Standard 1020 Flat. We then covered the 1020 Flat with a Clear Humidity Dome to retain the proper amounts of heat and moisture for the young seedlings to germinate and grow properly.

After sprouting in the 1020 trays for roughly 15 days, we placed the seeds into our Propagation Table, where they remained for approximately two weeks. Once developed, the smaller Starter Plugs were placed into larger Grodan Delta 4 Gro-BlocksTM and set in our Ebb & Flo System for an additional two weeks. Once both the seed and root system were established, the Gro-Blocks were transferred into Dutch Buckets, each filled with Horticulture Coarse Perlite.

Marnero Tomatoes in Micro Dutch Bucket System

Three of our four Dutch Buckets contain two plants each. For us, seven plants reached proper germination and were able to be planted, once these seven have been established and are ready for trimmings, each Dutch Bucket will be home to two plants. Since these tomatoes are great for the backyard or hobby grower, we are producing our Marnero Tomatoes in our smallest and most affordable system, the Micro Dutch Bucket System.

This system consists of four PolyMax® Dutch Buckets, which sit directly on top of the 38” wide by 30” long nutrient reservoir. The nutrient-rich water is supplied to each Dutch Bucket with the help of a recirculating pump, 3/4” supply tubing, 1/8” micro tubing, dripper stakes and more (all required watering supplies come included when you purchase a system).

PolyMax Dutch Bucket SystemPolyMax Dutch Bucket


For ideal growth, Marnero Tomatoes should receive 16 hours of supplemental lighting. Our Micro Dutch Bucket System is lit using one 1,000 W metal halide light fixture placed directly over the center of the system.

Lighting for Marnero Tomatoes

Temperature and Humidity

Here in our state of the art grow room, we aim to keep our tomatoes at 80 degrees Fahrenheit with 50 percent humidity. For those who are familiar with our facilities, our Marnero Tomatoes can be found in Grow Room 2, along with the rest of our fruiting crops. If you haven’t yet seen our facilities, you can stop by our office anytime for a free tour, or you can enjoy a photo tour by visiting our recent Grow Room East Photo Blog.

Nutrient Requirement   

To keep these tomatoes healthy, we keep the Nutrient Reservoir at a pH of 5.9 with a nutrient concentration of 3.7 EC.


Jumbo Tomato ClipsMarnero Tomatoes at full maturity range anywhere from 7-10 ounces in weight, so support is a necessity. For our Micro Dutch Bucket System, we have constructed a stand-alone frame using PVC pipe, which assists us in providing proper support. One very noticeable quality of the Marnero Tomato is that the stems and suckers are very thick in diameter. It is because of this that we use our Jumbo Tomato Clips and Two-Piece Radial Hooks for support. We also have several of our Tomato Rollerhook® Assemblies attached to our PVC frame to keep the shoots and stems in place. These additional supports enable the plant to grow healthy and strong and produce the maximum yield possible.


Within the Micro Dutch Bucket System, caring for Marnero Tomatoes is relatively simple. This crop requires traditional suckering and pruning techniques and regular visual observations for insect damage or nutrient deficiencies. You can test the nutrient reservoir using a Waterproof PH/EC/TDS/°C Meter if plants are yellowing, wilting or suffering from tip burn, as there may be an imbalance in your nutrition. This is an indeterminate crop, so as long as you continue to care from them, they will continue to produce.

We have discovered that Marnero Tomatoes can produce two main leaders. Where most traditional fruiting crops have just one main leader with several shoots coming off it, nearly half of our Marnero Tomato plants have produced a second main leader. We have left this second leader on the crop, and we have not noticed a lack of nutrition throughout. We have elected not to clip or remove the second leader, because it is ultimately providing us with additional growth.

Main Leaders on Marnero Tomatoes


For greenhouse growers, this crop must be hand pollinated. We used our VegiBeeTM Garden Pollinator on our crop.


First Tomatoes

Our first fruit

At maturity, these tomatoes are a deep red with a slight hint of purple in color. Harvesting should be done when tomatoes are anywhere from 7-10 ounces in weight and are displaying good, healthy color. For those that will be selling and shipping these tomatoes, harvest anywhere from a few days to a week before the crop hits full maturity. This will ensure that when the product arrives at its final destination it is healthy and has maximum taste. This variety is one of the top slicing tomatoes, as it is extremely close to the Cherokee Purple, so there is sure to be a high demand for this product.

Interesting Facts

The Marnero Tomato is an Heirloom-like hybrid. Did you know that seeds are classified as Heirloom only when it can be traced back at least 50 years? As a hybrid of one of the most popular Heirloom tomatoes, the Cherokee Purple, Marnero Tomatoes are a highly sought after substitute.

If you have any additional questions about caring for Marnero Tomatoes, let us know by leaving a comment below. Keep up with us each week on the blog and be sure to check back in February for the next installment of our Plant Profile series.

No comments yet

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s