This is from an email conversation I had with David at Century Farm Orchards:
Goldrush seems to self-limiting on most rootstock, so a MM111 Goldrush will max out at 10 to 12 feet if pruned properly.
I’m currently planning to keep the Hooples at around the same height, but I’m not limiting the Hooples too much for the sake of uniformity. Hopefully the GR gets up to 12 feet, I’m hoping it will since we have longer summer days than Century Farm Orchards does.
I had heard that Goldrush is not vigorous on most rootstocks but my Goldrush on B9 are one of my most vigorous varieties. About the same as Fuji. Many varieties on B9 are too small to be useful, but not Goldrush.
I have 3 rows of Goldrush planted in 3 different years at 3X12. About 100 trees total. I’m located about half an hour from Century Farm Orchards. I have no experience with Goldrush on MM111, but my Hoople on MM111 is not especially vigorous.
My GR is on M7. It does not grow much. After 4 years, it is about 8’ tall. My tree is productive.
I don’t want to sound like whining but I am so tired of so much rain. It started in late July and has not stopped. I can’t recall a week without rain. Most of the time, it has rained a couple of times a week but lately it’s every other day. Last week, we had Nor’s Easter in late Oct.
Today it rained. Tomorrow it will rain. For the next 5 day forecast, it will rain every other day. If it does not rain, it’s cloudy. This fall, there are not enough sunny days for fruit to ripen well. How on earth my apples will sugar up with this weather?
I will leave my GR until temp drop to 21-22F.
Paul,
My GR shape is usually tapered. They got round/fat this year, probably because of rain water!!!
If taste is what you are after, you do not want to grow anything on M7. The only thing M7 has going for it is almost foolproof, that is why it is the favorite rootstock for Big box stores, NO Returns!
How does rootstock affect apple flavor? That surprises me.
I am not sure what you meant and how you base your statement on. Never heard of M7 acts the way you described.
I use to be big in growing apples and stonefruits, since i have move to Arkansas i am more into less spray fruits. For flavor it is understood that m27 makes a difference in taste, not sippid. Because when i live in the city i had to grow everything smaller. 18 years ago (z6a)
I remember growing apples tree’s called broomhandles, sidebranches are only 8 " long, tree’s planted 16" apart in long rows, very pretty sight.
Apples growing on m27 get larger fruits, m7 get a whole lot more but smaller. If you want more fruit ,plant more tree’s with m27’s.
I have a GR on M7 and one on Bud9 interstem. They both tasted the same to me.
I have one tree of GR on M7 and it is much more vigorous than my one on Bud9 interstem. I want both to be trained to no higher than yours at 8’ which mostly eliminates a need for a ladder.
I like my trees short 
@aap, my understanding that factors like soil, weather, etc., has far more influence on taste of fruit. I am not sure about the influence of rootstocks on taste. I’ve heard about rootstocks influencing fruit size.
M9 tree is just a little bigger than m27 but not by much, unless you have a vigorous type variety. If you are an orchard guy, which i am not you have a different way of using rootstock, m27 is not one of them, m9 might. If you doing just a couple acres, i go with m27’s or 9’s.
I agree with you about the size of the fruit being influenced by the rootstock. I remember having two different rootstocks with the same apple on them years ago. The apples on one were always smaller than the other one. They were only about 25 feet apart. They tasted the same but just the apple sizes were different. I thought that was odd back then.
I am really glad I posted my complaint about Goldrush and low vigor, I will go with MM111 then, thanks for the recommendation.
I haven’t heard about rootstock choice affecting taste either, only fruit size and maturity.
Mamuang, we had similar weather like you last year and my Goldrush didn’t ripen properly but kids ate them all anyway. This year it’s a completely different experience.
We got some great weather, even my latest peaches that usually stay green, ripened at the beginning of October (Redhaven +70).
When apple trees are very vegetative, the growth quickly shades spur leaves and fruit while also growing root vigorously. At some point the growing shoots apparently stop serving the fruit so much as leaves, wood and roots. The shade this growth casts permanently kills the ability of shaded leaves to photosynthesize, and these are the leaves that can serve fruit (size and sugar content) and next years flowers best.
I believe summer pruning can control a lot of the negatives of vigorous rootstocks, but it requires more work than more dwarfing ones. I wish this opinion was based on solid research, but the industry doesn’t really care about how fruit tastes (brix) so much as appearance. Summer pruning is recommended primarily as an aid to getting better color and reducing summer fungus pressure. (I believe pruning in mid to late spring improves biennial baring.)
You can prune the top growth, but roots are a different matter, and excessive roots may contribute to more watery fruit in the humid region. This I’d like to know.
Meanwhile, I need to grow vigorous trees to keep ahead of the deer.
I would like to find out if this is the same the reason @aap thinks M27 and M7 produce fruit that have off-taste. He mentioned dwarfed rootstocks including M 9.
In the seventies and eighties when Nafex was the forum there were some very knowledgeable old timers then. They form opinions based on their experiences, nothing based on super technical stuff. I was in the middle learning as much as I could, so what I have learned I am sticking with that.
I knew T.O. Warren, who gave me a Warren pear that is still growing in my yard, Robert Kurl, I often took care of his 2 acres till his death and the list goes on.
So for what it’s worth.
Thank you for your input. I have two William’s Pride on M7 for closer to 10 years. I have not noticed any off-taste apples. My GR is also on M7 but this is the 2nd year offruiting. Last year was the first. The apples were as good as advertised.
I joined in the early 90’s. Still have stacks of Pomona. Learned a lot.
Alan, good to hear that. Are they still doing excursions to the different universities that has big agricultural programs, like Clemens, LSU,etc?
Miss those, get to know a lot of them.