Read anything by Stepp Holtzer. HE recommends quite a few things.

Check this out as well:

http://www.omafra.gov.on.ca/english/crops/facts/00-007.htm

""....Except where previous experience has been favourable, growers are cautioned against making extensive plantings on M.7."

IT goes on about poor anchorage as well. Try and stick with legitamate sources of information. I look for .edu in regards to most plant info.

ozzz:

I would never plant an apple on seedling root no matter the issue. I'm also not fond of M7. I'd suggest a dwarfing root that is resistant to woolly aphids. Possibly one of the new Geneva roots. And if you think your drainage is that bad plant on a raised bed.

I'd go with M9 over standard or M7 even though it's not woolly aphid resistant. I had great luck in Amarillo with M9 on a soil that sounds similar to yours in drainage and texture. The woolly aphids are really bad here yet my trees on M9 are doing well.

I haven't read up on M7 rootstock, so I can't tell you whether it's good/bad for heavy soil. It doesn't sound like your soil is terrible, however. You might have "clay loam" if it drains in several hours. It might be an advantage in your dry climate, actually. I'd go ahead and plant the dwarf trees, if I were you. You could prune the standard trees to keep them within bounds, but you'd be fighting them a lot more. Honeycrisps are awesome in a cold climate, and Zestars are quite good too (but thicker skinned, to me). I haven't had a Scarlet Red.

Or, you can do your own trials and plant an M7 and a standard, then you'd really know for sure which is best! Good luck.

Thanks for the info guys! I have the standards in hand, and I just emailed OGW to see if they could cancel the M7 trees so that I can do some more research. Im not sure if they have sent them out yet or not but I havent received a tracking number or shipping confirmation of any kind so I dont believe they have.

In the drainage test I filled the hole full, let it drain, then filled again about an hour later and it drained completely in 7-8 hours @ approx. 2" per hour.

I do believe its clay loam, I need to do a jar test to get a better idea, I havent gotten around to getting a canning jar though ;)

Any more suggestions on rootstocks and/or apple strains I should look into!??

Im all ears!!

An excerpt from "The Backyard Orchardist" by Stello Otto.

M7 (also known as MVIIa) - This is often considered the ideal stock for the small semi dwarf tree, well suited to the home orchard. It has a nice open spreading growth habit and a good root system with strong anchorage when combined with all but a few scion varieties. At about 50% of standard size, it is similar in size to a peach tree and ideal for espalier or decorative cordon. M7 grows well on most soils but does best on fertile loam soils and clay soils that tend to have consistent moisture. It does require regular watering on dry sandy soils. Although susceptible to wolly aphids, it is resistant to collar rot. It does have a tendency to root sucker heavily and needs to be planted deeper than other rootstocks to reduce this problem.

The book is older, but is still the best fruit tree reference I can think of.

I agree with fruitmaven about the clay soil possibly being an advantage in your climate, since it retains water and nutrients well. At the same altitude here in NM where we are a tad bit more arid, it seems that the clay soil allows many fruit trees to get by on little or no irrigation once established. I'm not aware of major disease problems with any apple varieties/rootstocks here on these soils.

Nearly all my apples on mm111 have died of collar rot b/c of my heavy soils. Even a couple on some friable loam atop a heavy underpan. However, all my bud 9 trees have flourished. If you can stand a dwarfing tree.

Guys, I really appreciate all the information and help on this matter.

As you can see, there is some VERY conflicting information here ... exactly opposite... and this is what Im finding online. So is M7 good in heavy soils or isnt it lol.

Some sources say a definate NO, some say most definately YES.

I guess Ill just plant the M7's and see?

ozzz:

One issue with M7 is lots of root suckers. So if you plant it you may be fighting suckers forever. I'd plant MM111 before M7. But I'd also plant M9 before MM111.

Here is a link that might be useful: apple rootstocks