G.30 Rootstock Final Size

megamav(5a - NY)June 28, 2013

Hi apple growers.
I am growing a Jonamac tree on G.30 and the height of the tree is getting up there.

My soil is pretty sandy, and I compost around the tree.
I was expecting my soild to be on the poor side of the fence but maybe im mistaken.

I was under the impression that G.30 with an average vigor scion would grow to about 12-14 feet.

Right now, this tree is in its 3rd season and its eclipsed 11 feet tall this month, only a couple of fruits on it, its still rather thin because this is its first full sun year due to taking trees out June of last year, but its thickening up nicely now.

For you apple growers out there, if you have a G.30 tree, what height did it reach before it topped out?

Im not complaining about the size at all, in fact im pleasantly surprised, because I thought it would be runted a bit due to the sandy soil, but it seems to really thrive here so far.


Thank you for reporting this comment. Undo
alan haigh

The scion is as important as the rootstock in determining the vigor of any given tree- particularly with free standing type rootsocks. I don't grow Jonamac, so I can't help you there. You've already indicated that you are aware that soil is a factor, and so is climate and irrigation, of course.

I've never allowed any tree to "top out" but I suspect your tree could easily reach 30 to 40' if you left it to its own growth.

G30 is semi-standard or semi-dwarf depending on who is describing it- about the vigor of M7. That would be 50 t0 60% the vigor of a seedling tree if that usual ball park figure is actually accurate. I have seen 60' tall ancient apple trees on seedling rootstock.

It is the precocity of the G 30 rootstock that allows you to keep it fairly short while not delaying fruiting so the tree should probably top out where you top it. For maximum production that would be at about 14' for a Christmas tree shaped tree. You could grow it taller or shorter than this and still have a productive tree.

    Bookmark   June 29, 2013 at 5:27AM
Thank you for reporting this comment. Undo
megamav(5a - NY)

Thanks harvestman.
I've included a picture of the tree.

By your observation, we can "stretch" our rootstocks out a bit by extending the tree's non-fruiting period?

I think this year will be the last of its restriction on fruiting if thats the case. G.30 seems to produce laterals very easy, so I could see how it would induce fruit early.

Im thinking it will end up around 13 feet tall after this year.

It also sparked me thinking about something else... I'll open a new thread about that....

    Bookmark   June 29, 2013 at 12:25PM
Thank you for reporting this comment. Undo
alan haigh

fruiting is dwarfing

    Bookmark   June 29, 2013 at 1:08PM
Thank you for reporting this comment. Undo

Does anyone know of a chart of the vigor or different apple varieties?

If the variety accounts for around half of the ultimate tree size then should I be taking the tree variety into account when laying out my orchard? Seems like most folks that plant dwarfs space them all the same regardless of variety.

I am trying to figure out how to maximize the spacing for my B-9 and G-11 trees I planted last fall and will plant this fall. I would appreciate any input on this topic, thanks, Chris.

    Bookmark   June 29, 2013 at 1:46PM
Thank you for reporting this comment. Undo
alan haigh

A quick search pulled this up. Didn't check it for my take on it's accuracy.

Here is a link that might be useful: relative vigor of apple varieties

    Bookmark   June 29, 2013 at 2:31PM
Thank you for reporting this comment. Undo
bob_z6(6b/7a SW CT)

The Home Orchard Society list has a lot of entries, but it isn't very granular with 3 categories. Almost everything I have is in the middle, along with a few T3. Even Honeycrisp is considered mid-sized, so the middle category is pretty broad.

I like the Orange Pippin categorization better, as they break it down into 6 levels. But, they are missing that datapoint for some varieties, such as Jonamac.

They also have a tree height calculator, but from my experience it underestimates size by quite a bit. For example, I have a Goldrush on G11. Given the most optimistic soil and rainfall settings(for growth), they say it should top out at 7.4 feet. After 2 years in the ground, I measured it at 11 feet this spring, though I've since bent it to stay at around 9.

I have 3-4 of each (I know, not a huge sample size) and while G11 and B9 are both considered dwarf, the B9 seem to be less vigorous. I actually prefer them, as they seem to take better to being spread out with branch bending. I've managed to keep them at 8' and under, while some of the G11 have tried to get away from me.

    Bookmark   June 29, 2013 at 3:10PM
Thank you for reporting this comment. Undo
alan haigh

Bob, I agree with your assessment of the HOS list. In fact there are almost no varieties judged least vigorous so it really only breaks down to where almost every variety is either 3 or 2- very or moderately vigorous.

    Bookmark   June 29, 2013 at 5:43PM
Thank you for reporting this comment. Undo
fruitnut Z7 4500ft SW TX

What I'd do with that tree is head it back to give it some backbone. You might have a 13ft tree next year only able to support a few apples. My trees would be much stouter to support the fruit.

    Bookmark   June 29, 2013 at 7:44PM
Thank you for reporting this comment. Undo
Noogy(6 sw mi)

Fruitnut has a point. Though a pear, my Tennessee's have been very vertical and stretchy, despite being in full sun. One of them suffered from pseudomonas, so i cut it back to 30" when I first got it, so now it doesn't bend when the wind is blowing. Although I have pears on the taller ones, I've had to stake them as they make me nervous, like a bendy willow. Screw that. If I had them spaced @ 5' super spindle, might be acceptable. Heading them back from 10' to 6' is tempting. I staked them, I hope they stiffen up. Though mega's tree isn't as limber as mine, I'd consider Fruitnut's advice.
Thanks to this forum and all contributing members. You make it happen. As virtual as it may be, the relationships we form lead to real results. Cheers! PBR time!

    Bookmark   June 29, 2013 at 9:38PM
Thank you for reporting this comment. Undo
alan haigh

I hadn't considered corrective pruning since you didn't ask the question. Every fruit grower develops their own specific methods. Here's my 2 cents.

I usually cut off wood that goes below horizontal while training, mainly because I believe such wood is dwarfing. Generally, though, my rule of thumb is the less pruning the better.

If a branch is too lanky to carry a fruit load, remove the fruit, especially on the outward part of a lanky limb- only head back branches that refuse to create secondary wood.

To coax secondary branching it is best done after a tree is in growth, around mid-spring. After that you can guide the response with several interventions during the growing season, pinch pruning to encourage one shoot to grow dominantly in the direction of the branch and to subdominate the secondaries.

Of course, there's more than one affective way to skin a cat (who actually skins cats?), but I personally work on the theory that when establishing a tree, the less pruning the better, aside from removing oversized scaffolds (more than 33 to 50% the diameter of the trunk at the point of branch attachment) and pinching shoot tips to steer growth. .

    Bookmark   June 30, 2013 at 6:55AM
Thank you for reporting this comment. Undo

Bob: I agree on underestimating growth of the dwarf rootstocks. Some of my G-11 and G-16's planted last fall that came from Cummins were 3 to 4 when planted and now are already over 7 feet. I am not sure if this is good or bad. You mentioned bending to the trees. Do you mean bending or folding the top of the central leader so that if faces the ground?

I have read the main idea in the tall spindle method is to not to head the central leader but I am not sure what else to do to keep the height at around 8-9 feet and avoid the dreaded ladders.

    Bookmark   June 30, 2013 at 3:03PM
Thank you for reporting this comment. Undo
megamav(5a - NY)

A little history behind that tree.
This is its 3rd season in the ground.
Its lanky because in its first season, it was surrounded by tall trees, and didnt put on much weight, and last year it had those same trees around until 2nd week in June. After the trees were removed it started putting weight on.
This year, its become much thicker on the trunk.

I can leave it alone and let it get thicker, I can renew limbs in the fall, or I can halve the limbs.

Not sure what to do, I err on the side of letting it do its thing until it needs intervention.

My 2 other trees are more upward, and were planted last year and didnt have the tall trees near them for long.

Im open to suggestions.

    Bookmark   June 30, 2013 at 7:47PM
Thank you for reporting this comment. Undo
megamav(5a - NY)


My G.11 Kidd's Orange Red is in its 2nd year, Headed it back this spring, and its now up to 7.5 feet tall.

Needless to say, I hope it puts on a full load next year to stunt its height. Im good at 9 foot.

    Bookmark   June 30, 2013 at 7:51PM
Thank you for reporting this comment. Undo
bob_z6(6b/7a SW CT)


I've read the same thing about Tall Spindle. I figured that if I wasn't supposed to head it, but still wanted to keep it low, that the best thing I could do is bend it to the desired height. Since flat or hanging branches aren't supposed to be vigorous, I figured this could work. If it works for branches, why not the leader...

Basically, I tie a string around the top, then pull it down until it makes an arch shape. I've also done this with some of the other upper branches (not just the leader) in my 2 largest trees (Goldrush on G16 and William's Pride on G11).

The below picture is the G16 Goldrush. It was over 11 feet this spring, while the top of the pole is just under 9'. I took the photo at dusk with flash on, which makes it pop out from the background so you can better see the branches.

I'm not sure if this is a normal procedure, but I've done it on several trees. It has seemed to work so far, but it's still early and I'd love to hear from others.

    Bookmark   June 30, 2013 at 8:51PM
Thank you for reporting this comment. Undo

Thanks for the picture Bob, I am going to try your method. I dont see any downside to the method, if nothing else, it will probably postpone having to head back the central leader.

Have you also stopped applying fertilizer to slow down your dwarf trees?

    Bookmark   July 2, 2013 at 6:14AM
Thank you for reporting this comment. Undo
bob_z6(6b/7a SW CT)

I applied fertilizer the first two years, but none this year. Even so, they are well mulched with woodchips (which I've added to) and there was a decently thick layer of leaf mulch under the woodchips, so I suspect that the soil is still plenty rich.

I think part of what made these trees grow so well is that I kept them well watered the first year with drip irrigation. I have some I planted the next year (last spring) which I didn't water as well and some of them have lagged behind.

    Bookmark   July 2, 2013 at 9:30AM
Sign Up to comment
More Discussions
Fruit drop on Paw paw
Last year I pollinated by hand very thoroughly. I got...
How does well water with Rust affect pH?
We use well water with lots of rust in it. Will it...
Helen Zone 6 Ohio
Are these roots that are forming on a callery pear cutting in water?
As you may know, i took cuttings of a flowering pear...
Calling all Sweetcrisp owners!!!
Dear Sweetcrisp owners, Over here in Australia we are...
My Backyard planting experience (so far) - Zone 4a/b Quebec, Cana
Hello all, When starting out I have found this forum...
People viewed this after searching for:
© 2015 Houzz Inc. Houzz® The new way to design your home™