Coffee with Tom Greenwell |March 7, 2023

Episode 3: All About 100% Kona Coffee Grafting

This month, we addressed a question from the audience! What is Coffee Grafting? Tom answers what it is, its benefits and all about the Greenwell Farms nursery technique. Tune in for this extremely insightful conversation and the way that it is helping rebuild Coffee Leaf disease resistant trees for the Kona Coffee Belt community.

[00:00:05] Matt Carter

I’m Matt. This is Tom Greenwell, our owner and CEO, and welcome to the third installment of Coffee with Tom Greenwell. Cheers.

[00:00:12] Tom Greenwell


[00:00:12] Matt Carter

How are you doing this morning?

[00:00:13] Tom Greenwell

Very good!

[00:00:15] Matt Carter

Good. Now, we had a question from one of our customers about grafting the coffee. And so no better person to ask on the farm than Tom. And so why did we start grafting coffee?

[00:00:26] Tom Greenwell

Well, we have a nematode that attacks the root system of the coffee tree and it eventually will our trees will overproduce and kill itself because it doesn’t have enough root base. So we’re using a rootstock from an Arabica and a Liberica that are resistant to the nematode.

[00:00:52] Matt Carter

I see.

[00:00:53] Tom Greenwell

And what we want is our wonderful tasting coffee that we grow here and we graft that coffee on top of this rootstock.

[00:01:06] Matt Carter


[00:01:06] Tom Greenwell

The rootstock protects the tree from the nematode and provides actually a lot more nutrients to the plant.

[00:01:16] Matt Carter

Amazing. So I calculated that we grow 11 or 12 varieties of Arabica that upper, if you want to come in I don’t know if you can see that, but that upper green section that we call the scion is what he was talking about, has the really delicious coffee beans. And then that brown portion underneath is the rootstock and you can see how they kind of fuze together. How long does it take for a graph to become stable after you fuze it?

[00:01:42] Tom Greenwell

After we’re done actually gone through the grafting procedure it takes about six months is what I like to see at least minimal.

[00:01:51] Matt Carter

Do you all coffee farms in Kona graph their trees?.

[00:01:54] Tom Greenwell

No, no. It takes a lot of work. It’s expensive but I think it’s well worth the expense. Number one, because we get a much better crop.

[00:02:11] Matt Carter

I see, so higher yield, healthier trees.

[00:02:13] Tom Greenwell

Yeah. Healthier tree means better tasting coffee.

[00:02:16] Matt Carter

Gotcha. Interesting and so we’ve been doing this since about 99′, 2000’s something like that?

[00:02:23] Tom Greenwell

Yeah, we identified the nematod as a big problem here in 98′.

[00:02:29] Matt Carter


[00:02:30] Tom Greenwell

And about 2002, we were completely converted over to grafted trees here at the farm.

[00:02:37] Matt Carter

I see, now this is seed grafting, right? As opposed to shoot grafting?

[00:02:42] Tom Greenwell

Right. Right. We actually use the seed.

[00:02:45] Matt Carter

I see. So is there a benefit to that? Because the other one is cloning and this necessarily isn’t cloning, is that correct?

[00:02:52] Tom Greenwell

Right. Because when you use a seed, you can have a cross between two different trees and even if they are the same variety. You can get a little different, you get pollinated. But coffee only pollinated about 10% of the seeds. So it’s not a big change. Cloning is probably takes a lot more care. It’s a lot, your losses from the actual grafting is about almost 50%.

[00:03:29] Matt Carter

Wow, so now our nursery manager told me that she has a 96% success rate with her seed grafts. That’s amazing.

[00:03:36] Tom Greenwell

That is. They do a really good job.

[00:03:38] Matt Carter


[00:03:39] Tom Greenwell

It takes, it takes time to get to that point.

[00:03:41] Matt Carter

I see.

[00:03:42] Tom Greenwell


[00:03:42] Matt Carter

So what we were talking about a couple of weeks ago that we’re introducing new varieties of coffee to Kona to be leaf rust resistant. We’re still going to use the grafting system, that doesn’t change?

[00:03:55] Tom Greenwell

No, it doesn’t. We absolutely everything will be grafted till we find a variety that’s resistant to nematodes.

[00:04:05] Matt Carter

I see everything.

[00:04:06] Tom Greenwell

That tastes good. So far we haven’t.

[00:04:08] Matt Carter

Now, this is a weird question, but on an annual basis, how many trees are you guys grafting here?

[00:04:15] Tom Greenwell

Well, we’ve been doing about 15,000 trees a year.

[00:04:19] Matt Carter

I see.

[00:04:20] Tom Greenwell

Primarily, it started for us for replacing the farm here. Growing out our new farms. Now we’re grafting trees to help the rest of the farmers in Kona with the rust resistant varieties. As this one here right here is a rust resistant.

[00:04:38] Matt Carter

So we’re kind of ramping up production to to help the belt.

[00:04:42] Tom Greenwell


[00:04:43] Matt Carter

Amazing, that is a lot of work.

[00:04:43] Tom Greenwell

Yeah. Not every farmer can have the time to graft and do that and, you know, and grow. Just trying to help out the community.

[00:04:53] Matt Carter

Amazing. Well, guys, there you have it. Hopefully that answers your question about grafting and until next month. Aloha.

[00:04:59] Tom Greenwell


Watch our previous episodes here:

Episode 1: Facing Future

Episode 2: Talking About the Family Farm

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