Old crabapple rootstock that won't die!

Good morning to all you lovely permies peeps! I'm looking for some help from some of you experienced arborists out there. I have 2 questions; how do I stop suckers from an old root system, and do I need to worry about the root system passing along apple scab to new trees?

Background story: We used to have an old crabapple on our front lawn that was there when we bought the property in 2007. This was a beautiful tree, at least for 8 days in the spring when it was fully bloomed. Outside of those 8 days it was ugly, and would be almost completely bare by mid July every summer due to a bad case of apple scab that I couldn't get ahead of. After several attempts to rehab it, I decided to take it down and start a mini apple orchard instead. During its final years, we would get some red leafed suckers popping up on the trunk and along the roots, which I would just twist off when they were big enough to grab. Now that the stump is gone, they're worse than ever. The photo is a week after I last mowed. They grow faster than the grass! The new apples are yellow delicious, red Jonathan and stayman Winesap. They've been in the ground for about 18 months and only the Winesap is far enough away where no suckers are popping up around it.

Still getting the suckers popping out of the ground

From your picture, it looks like you are letting the sprouts grow fairly tall before mowing them off. That's not going to do you any good. To kill the roots, you have to deny them any leaf produced nutrition. You've got to chop off the leaves as soon as they appear. Eventually the roots will run out of energy and die. Take a shovel as soon as a sprout appears and shove the shovel in at an angle to cut off the stem below ground. Don't let any sprout survive. Cut them off every day if you have to. Then it won't take too long for success.

If you can dig them up with some root sections attached, then you'll have a lot of free rootstock!

Steve Thorn wrote:If you can dig them up with some root sections attached, then you'll have a lot of free rootstock!

This was my thought! Or just graft on them in place if they are already well spaced, and dig up the ones in between.

I don't think apple scab is systemic, so the roots aren't "infected" with it. The fungus is probably in your soil and will get on any apples you plant. You'll likely be limited to scab resistant varieties anywhere around there, assuming you don't want to spray fungicides. I do believe many apples are highly resistant, though? There's a table on this page:

https://www.canr.msu.edu/news/a_review_of_apple_scab_resistant_varieties_for_commercial_growers

If that were my lawn, I would have a load (or two) of wood chips brought in.

Piled over all the sucker to be 6 to 12 inches thick so no sunlight can get through.

Maybe even put down some cardboard though that might be overkill.

Jim Fry wrote:From your picture, it looks like you are letting the sprouts grow fairly tall before mowing them off. That's not going to do you any good. To kill the roots, you have to deny them any leaf produced nutrition. You've got to chop off the leaves as soon as they appear. Eventually the roots will run out of energy and die. Take a shovel as soon as a sprout appears and shove the shovel in at an angle to cut off the stem below ground. Don't let any sprout survive. Cut them off every day if you have to. Then it won't take too long for success.

They are very vigorous. This was less than a week after mowing. We shall see what the spring brings, but I'm guessing me and my spade shovel are going to be best friends for a while.

Steve Thorn wrote:If you can dig them up with some root sections attached, then you'll have a lot of free rootstock!

I would love this, but alas, even though I want my own food forest, my wife wants that nice, pristine suburban lawn. I may be able to sneak 1 or 2 grafts in, but even that will be difficult

Anne Miller wrote:If that were my lawn, I would have a load (or two) of wood chips brought in.

Piled over all the sucker to be 6 to 12 inches thick so no sunlight can get through.

Maybe even put down some cardboard though that might be overkill.

I have thought of this, but the roots are everywhere, and I'd have to kill the majority of my lawn if I went this route, and if I did that my wife would have me sleeping on it.

Winn Sawyer wrote:

Steve Thorn wrote:If you can dig them up with some root sections attached, then you'll have a lot of free rootstock!

This was my thought! Or just graft on them in place if they are already well spaced, and dig up the ones in between.

I don't think apple scab is systemic, so the roots aren't "infected" with it. The fungus is probably in your soil and will get on any apples you plant. You'll likely be limited to scab resistant varieties anywhere around there, assuming you don't want to spray fungicides. I do believe many apples are highly resistant, though? There's a table on this page:

https://www.canr.msu.edu/news/a_review_of_apple_scab_resistant_varieties_for_commercial_growers

This, and killing the rest with a spade, is probably the way I have to go. The wifey doesn't want too many trees out front, there's no room in the back yard, and the side yard is my garden. Of course, all 3 trees I planted (semi-dwarf red Jonathan, yellow delicious, Stayman Winesap) don't seem to be scab-resistant, so I may be looking for crosses from that list you provided (thanks!) to squeeze in-between. I definitely am anti-fungicide, but I'm also pro-apples, so I'll do what I must. They're basically still whips, so only time will tell.