161. Grafting Organic Tomatoes for Market | David Wolverton Returns | Arlee, MT

Welcome to episode 160 (oops! Should be 161!) of the Organic Gardener Podcast! Today I am excited to introduce a returning guest from episode 70, so almost 100 episodes ago, he dropped golden seed after golden seed, so I know listeners are going to hear from David Wolverton from Arlee, Montana!

Last time we talked about tomatoes, and grafting them and growing them in cold areas, and also the Farmer’s Market, when you decided to go back to the Farmer’s Market after taking a break to take care of you parents, you asked what do you need? I think that’s a great tip to listeners, ask what does your market need, don’t just say I want to grow mushrooms, or eggplants, like ask what does the market need, and they told you tomatoes, and also they said do something about the price.

I met you because I saw someone with tomatoes and said how are you getting tomatoes in June and they said they got them from you… and you were starting them in December, and so I am reaching out to you know because it’s December to see what you are up to…

Tell us a little about yourself.

I’m retired, as you mentioned I took care of my parents, that pulled me out of the workforce, but then I wanted something to do, and I asked what would be a nice contribution to the community as well as keep me entertained?  The farmers market was what I was doing so I thought that would be good. And as you mentioned, what am I doing, well I am just getting organized …

Today I start tomatoes again, I start for this upcoming season, it seems kind of early but I grow for my own greenhouse plus I graft of other people, who raise tomatoes in green houses….

Not Hydroponic

I need to add immediately, these are not hydroponic… I do not do hydroponic for greenhouses, nor do these other people, we grow in dirt, real honest to goodness dirt, we think that is key to having a much better flavored tomatoes.

Hydroponics have their place in the winter nothing better then a hydroponically grown Missoula, but when the season exists it’s better to have them growing in the natural way with the soil… so that’s what we do, the grafting as well as the hoop houses we use allows for a much more expanded season… So the target this year is to have tomatoes at the market in May, I didn’t pull it off last year, but  I actually had one grower, he did…. he had fresh homegrown tomatoes in May for the farmer’s market.

Wait so are you growing these from seeds, or growing them from grafts?

Grafting Vegetable History

Certainly the grafting of vegetables is a take off something people have done for thousands of years, the bible even mentions grafting olives and other fruit trees in the Mediterranean back 2000 years and earlier… so it’s accepted method… when it came fro annual vegetables, people said what’s the point they only live one year….

Well in the 1920s the Japanese started experimenting with grafting tomatoes, eggplants, peppers, melons and cucumbers… Their soils are heavily used, it’s a very highly populated country with  a limited amount of land, the build up of diseases was problematic, they also needed to maximize production. So these ingenious people in the 20s they developed the grafting of tomato that I now employ.

In Europe and Asia the majority of tomatoes and eggplants are grafted. In the US, it’s a much more of a novel concept. We have more space, more land where we can rotate the crops we can move around so the soil disease buildup isn’t as problematic as it is in a more crowded country.

Grafted Tomato Vine Advantages

…. Vegetables there are Never-less some advantages.

One of the advantages is, the grafted tomato vine lasts much longer…. in hydroponic they do use grafted plants…. that doesn’t make sense because in a greenhouse keep perfect temp but they still use grafts because it enhances longevity of the vine, they get a lot more production, they don’t have to replace in such a rapid cycle as they would normally.

For those of us that just grow seasonally the advantages are a grafted tomatoes plant is they have better cold resistance, they aren’t frost resistant… cooler soils aren’t nearly the problem

  • better cold resistance
  • productivity is higher
  • vines last longer
  • overall benefit is tremendous

Those who I have grown grafted plants don’t want to grow the ungifted plants now, they do prefer grafted plants as I have discovered…

Grow 2 Sets of Seedlings

Grafting is not that exotic or strange, you do grow 2 sets of seedlings… you do grow the rootstock which is special, it’s a hybrid of the standard tomato plant with the exotic relative of South America …  It has a much greater rigor…

tomato resistance to soil microbes that might infect and kill the plant… and then one uses regular tomatoes for the top part… if you like the Big d or one of the heirlooms, you can slice it and put it on top of the rootstock, then when it joins you have sort of a frankenstein tomato but it’s a vigorous plant that has the best of both worlds…

The rootstocks don’t produce a tomato that is worth anything… like I say it’s a hybrid that is kind of wild, but the vigor of the roots is impressive and that passes on to the top part that produces the quality fruit.

When it comes to growing the more difficult greater like the varieties that tend to produce less, when grafted onto the rootstock, they can behave almost like a hybrid, they are still an heirloom, and still taste delicious, they last longer, are more disease resistant, and productivity is higher, and I think the flavor is better.

So they:

  • last longer
  • more disease resistant
  • and productivity is higher
  • better flavor

That’s because if the tomato vine is stressed, if the soil is too cool, if it can’t get the nutrients uptake it needs it affects the flavor, you have a less taste tomato. But if you have rootstock who can scrounge through the ground and get the micro nutrients it needs and the water needs, and also at a more steady level, so the plant is healthier but the fruit tastes better so the advantages go on and on….

That has been an overall theme of my soil… that the healthier your soil, the better your plants are gonna be, andRuss Metge from Simply Trees talked about the same thing in Episode 130 about fruit trees that the healthier your tree the less bugs and diseases your gonna have problems with, the better your fruit and vegetables are gonna be….

What do you want to talk about next?

Fertilizers and flavor

Well, especially novice gardeners especially when it comes fertilizer, different plants require different amounts. The old saying more is better is simply not true, more is better, more is deadly. You have to have to have right amounts and tomatoes are an example.

If you have too much nitrogen, the plants grow heirlooms vigorously but the fruit tends to have less flavor. So if one maintains a balance in the nutrients, one has a slightly less vigorous plant but the fruit is tastier.

What I mentioned with the grafted plants is if there is some problem with the fertilizer that is not as immediately apparent then they help iron that. One still needs to pay attention to soil health

organic nutrients and organic methods are better, and keep the plant more alive, healthier transfers to a healthier root system, which makes a healthier plant with more nutritious fruit and more tasty.

One thing I would mention, with the rootstocks, ignore totally does’t want to use fertilizers, particular the high nitrogen, specific tomato formulas, organic and otherwise and those are the ones you should use …

Is there are time that is the best time to fertilize?

If I was more ambitious I would fertilize in the fall. I use organics… I use fishmeal, bone meal and kelp meal, a mineral supplement that has a high magnesium, and sulfur and potassium level …

Sul-Po-Mag Organic FertilizerSul-Po-Mag is one of them…. Those four are the basics I use…

  • fishmeal
  • bone meal
  • kelp meal
  • a mineral supplement that has a high magnesium, and sulfur and potassium

I let them get into the soil, start feeding soil.

Basic premises of organics… feed soil then soil will feed your plants

better then mainlining your plants with direct fertilizations like chemical fertilizers tend to do…

So the soil starts  breaking down the compounds…

I’m not disciplined to get it done in the fall, perhaps in Feb or March get fertilizers worked in, and I can get the plants in and it’s already starting to act.

One hybrid, you want to say between a natural and a chemical is liquid fish, it is organic, it is natural, but in the liquid form does tend to feed the plant more quickly, That’s great when one is greater, it gives little plants a boost right way, while they are living off that can get roots into the nice naturally enriched soil that has other ingredients that are already breaking down as the nutrients become available…

So, are you starting your plants, you start them in your house right? And did you say this already, are you doing seeds or are you just grafting?

I do the seeds even for the grafts… the reason is, it’s true you can carry the tomatoes from year to year, they tend to accumulate viruses… If one starts with seed, from a good seed source, you have fresh plants.

So I start seedlings both rootstock and top plant, and once they get to a proper size, I slice the top off the rootstock and then attache the top part of the choice variety. Then I put them in a little chamber that I set up because they need 100% humidity for a few days because obviously the top part has lost it’s roots, so while they are healing and grafting they can not allowed to dry out, I keep them misted and moist. That way they are able to come together. But they do start out both as seeded seedlings…

Some people do see if they can keep a tomato alive for a while. It’s nice to experiment, but I don’t recommend it, because you’re borrowing last years trouble and importing it into this year…

So how did things go last year?

Overall a good year, as far as the weather, and so forth, it was usual. WE have such a see saw in Western Montana, but having the plastic covered hoop houses helps so much. There was a hail storm that knocked out the tomatoes in Missoula, and the tomatoes were just demolished by the hail!

I was immune to that, didn’t really have hail in Arlee but the plastic

makes sure your delicate tomato plants don’t get demolished… once again if it’s frosty, makes gardening so much easier, I am getting much less enthused about gardening out in the open and more thrilled with gardening under a hoop house… and not having to worry about the weather so much…

I finally got Mike some row cover to start experimenting with it, just basically this fall, but I think next Spring he’s gonna go full on… and hes’ really gonna grow some things. .this is gonna be our big year, this spring where he’s really gonna put 100% into it!

Hoop House Love

Here’s what’s amazing, instead of having one big greenhouse, I have these smaller hoop houses. One can get a big hoop-house, but the way I grow for my needs, I have gone with smaller, multiple units, that way I can start one earlier and save on energy instead of having to heat a greenhouse or hoop house… Then I expand..

They’re 12’ x 25’, that’s the dimensions of my little hoop houses

That allows to plant 50 tomatoes (transplanting 48)

Last year as I tallied the production I was able to get a good 20 lbs of tomatoes per plant, so in this little 12×25 foot area if one does the math, that’s about 1000 lbs, that’s about 1/2 ton of tomatoes in just a small area… it’s the way to go enhances production and ensures productions… it lets you keep the worst of the weather off, let the light in… put a heater and really enhances production…


  • enhances production
  • keeps worst weather out
  • lets’ light in
  • enables heat



Richard Wiswall talks about that too, in episode 102 most effective most efficient… He wrote a book called the Organic Farmer’s Business Handbook ….he’s retired now, but he just coaches people so they can be more effective and make a bigger profit, or just make a profit and be able to do it for a living!

That’s true, I don’t live off of this. But if I was to put a huge amount of resource in and get very little back eventually it becomes too expensive hobby, so I do want to figure out what kind of wage I want for myself, and I’ve modified things and changed things enough where I can pull off actually making enough money , so I can keep going and keep purchasing for innovations as they come along and experimenting but also to provide a much needed nutritious crop for the public. I also experiment extensively with varieties so I can provide the best food for people who come to my table!

That’s so true we definitely more nutritious food that is accessible to everyone!

Is there something you would do different next year or want to try/new?

As far growing from seed, the other fellow for who I have grown most of the plants, he and I have been trading off on some experiments, in the last year, between he and me, we planted approximately 52 different tomato varieties. We still had our main crops, the ones that have done well in the past but we would grow anywhere from 1-4 experimental plants.

So I am excited about one! I went to Spain the year before, I try to get to Europe at least every fall if I can, in Oct or November. I scrounge to see what is growing in the markets, northern Euro closing down… but in Spain, the climate permits that, they are still going full born with locally grown:

  • What are they growing?

  • What kind of tomatoes?

  • How did they taste?

  • What are they bringing to market?

Valencia and Barcelona

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In each city that I was spending much time in, in Valencia and Barcelona, I made sure I got an apartment that was just a block from their big fresh markets. So in la Boqueria,  Barcelona and El Mercat Central in Valencia.

I went to see What are they growing and what are they  bringing (to the market)?

Last year, I had brought back a tomato from the Central Market in Valencia. This family said we have been growing this for years, it’s our own seed, it’s our own variety, so they kindly gave it with me. I left it with a friend in Spain, who did the extraction of the seeds, the thing about tomatoes is tomatoes have to ferment a bit before the seed becomes viable. Then the seed has to be extracted and then washed and cleaned before it’s shipped anywhere. I was able to grow a huge Valenciano tomatoes that was huge and delicious! It wasn’t the only one there were others from various seeds and sources. 

Well, this year I grew another type called Tres Cantos. This Tres Cantos tomato, absolutely blew me away. I had just one plant all the space I had was for the one plant! This is now going to be my main large vine tomato for next year, flavor is just outstanding! It has done so well in Arlee! I hope to share, with with everybody who comes to my table. I mixed it with several others, and I was like Wow! what’s this?!

I had to wait for everything to ripen to focus on what was producing, I had this extraordinary tomato and I went back to Valencia and they weren’t there. So I was a little disappointed! So I went to Barcelona in front of my apartment was this booth and shops, and wouldn’t you know it they had the Tres Cantos variety! So I bought him out which will keep me inTres Cantos for several years… The other things is it is not a hybrid, so I can save the seed and start growing a large amount of plants. Then focus on the best ones and developing my own version of Tres Cantos!

How exciting I finally got to go to Paris this year! What an extraordinary story! I almost went to Spain, but I never made it, I lucked out and got a good deal on Expedia. 

Those can be good… I have had contacts going back several decades to spain, I what I do is start shopping for my ticket, months ahead of time, I’m also an opera buff, look at what’s playing… and then I have friends I want to see… logistics are a little daunting and I pull it off. If I can go earlier, I think France and England

barely get away as early as I do… if I want to go to England and France

mid oct- mid nov

prepare ahead of time

look at customer reviews

maps to see where they are

place in Valencia have used it 2xs

try to be the best kind of lodger

get better fares because


Paris too

ways to work this

people work hard to provide apartments always have a welcome when you go back…

one little purse advice

tourist buses

get on get off, as you

hop off,

then when the bus shows up

highly recommended

wants to see everything…

if you find someone, had bad days, less then polite…

Tell me about something that didn’t work so well this season.


most beautiful

big plants and purple flowers

spider mites endemic this year

tried growing eggplants under cover

couldn’t keep spider mites

ordered predatory mites

eggplants such mite candy…

eggplant munching mites at bay

if I am going to grow eggplants

open garden

start early

cover them

if there is any kind of cover over time…

tried to winter over in house

dominate no matter what I did

tomatoes and peppers

might see some spider mite



strong not unpleasant odor

quite effective

different variations

intersting spider mites and aphids

not a superior chemical advantage

even commercial growers

use soap spray


scary anti-mite

mix in the soil

whole plant becomes toxic

doesn’t work for edibles

not option…

in the garden

most of the time it works

I have had other people in this area who grow eggplants

just one little are this has been going on

Questions for people starting out

be patient to grow things is such a miracle

don’t look at disasters as a sign to stop

bit heartbreaking

A pleasure

all sorts of posting

most tomato markets

there are 3 markets


downtown Missoula a particular wonderful

all three interesting and unique

TUESDAY market evening… much smaller.. . Missoula interesting rather intense

people getting off.

say it’s very lucrative

enjoy it sell a lot… can make it…

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