Great discussion elsewhere on interstems. I have apple trees aged one to six years that I grafted on Geneva 30 roots. I put support stakes on some but not others. Does anyone grow G30 without support? Has anyone had brittle graft union problems?
I have some leaners that I propped up but no brittle union issues.
I have three trees on G30. No support needed. In general I find anything bigger than the M9 type size is fine for me with no support. Also no problems with graft union breaks, but I have only three trees. I have had several G11 unions break even though G30 is supposed to be the bad one for that. Also Krymsk 1 for stone fruits has had unions break.
I have Jonamac on G30.
Nice height for home growers and wide crotch angles promote early fruiting.
I still prefer G202. Similar size, no union issues and better resistance to soil pests.
A grower near me planted a few thousand trees on G30. She thought they would be freestanding but after 6 years, they have all started to fall over and they are installing a trellis system now.
Just found this when I was looking over rootstock threads in general here. It made me think about the Methley (b/c need reliable self-fertile) I want to try: on Krymsk1 as a fan against a fence. Would the support from the planting stave off a graft union issue? If not I may have to rethink that spot.
Update: G-30 looks like flash in the pan. Cummins Nursery put out their 2019 catalog today and as far as I can see it contains zero apple trees on Geneva 30. It appears they have phased out G 30 completely (edit: not true, see below, still selling it as rootstock). It may be many years before the verdict is in on Geneva rootstocks.
So far, I was satisfied with the 25 G-30 roots I got last spring. The only ones I lost were from over zealously rubbing sprouting buds on the rootstocks…(there sure were plenty of those) .where 2 or 3 grafts failed to take, and I killed the rootstock by leaving no bud to grow.
This spring will be my 6th year with several G30’s. So far-so good. Seem to be self standing and all yielded in the 2-3 years. They grow well in deep, fertile soils and are productive. I’ve not lost any trees to breakage as I have from other rootstocks.
I have G30 trees at a site very exposed to wind and with relatively poor drainage where M7 trees tend towards tilting and needing support but the G 30’s have performed fine for about 16 years, although I lost one tree that snapped at the graft union many years ago.
I think there may be a wide variability from site to site and region to region on how this rootstock works, but it isn’t a big deal to use a heavy piece of steel conduit at planting for insurance. I would recommend it over M7.
However, I generally use M111 because Adams CN doesn’t carry G30. 111 tends to anchor better for me than 7.