The bigger the better. Pots dwarf plants. The smaller the pot, the more dwarfed. It will survive, but at least an 18 inch pot. Maybe for a year or two than 20 inch. You can start smaller, say 16 inch, but increase pot size every year. Stop at 20 inch. Every few years change soil, trim roots.
When you remove plant do it on a cloudy day. You should slice roots on 4 sides, blade should be about an inch in, maybe 2 deep. Slice an "x" on the bottom. This will stop roots from swirling. If they swirl too much the plant girdles itself.
Water good once planted. The plant will need as much sun as possible. But keep it shaded the day of transplant, and slowly increase exposure over 2 weeks.

You can put it in bigger pots than 20 inches, but it is hard to handle, go as big as you can handle. i use dollys to move mine! Some are in 23 inch pots. I would transplant it after harvest most years. As the stress could cause it to drop buds if done in the spring. You could do it while dormant too.

I agree with Drew -- I'd go with a pot in the 10-20 gallon range, which is generally 16" to 20" in diameter. I just planted some dwarf apples on Bud.9 rootstocks, and I opted for 20 gallon pots.

Thanks for the info. I plan to buy 2 more apple trees of different cultivars, so I will be doing the same procedure for all of them. The trees will all get full sun (when it's sunny here in the rainy Pacific Northwest). It sounds like a 20" pot will work for me. I'm trying to keep my gardening budget low, so can I move the tree from it's current 10"-12" pot to a new 20" pot and leave it in there for the rest of it's life? That way I only have to buy one pot.

Thanks!

Your trees will still need periodic root maintenance (root pruning and replacing the potting mix), but 20 gallon pots should work well for you over the long term.

Good thread on m27 apples :)

I plan to plant 1 or 2 M27s this winter myself, also in the PNW.

For those with mature m27 apples trees, what kind of yield are you getting on mature trees - how many apples? I know it will depend on the cultivar, etc.

Surprisingly, I have not been able to find an answer to what kind of harvest these mini tree produce.

Thank you- Ed

How large the container SHOULD be depends on your soil choice and how much tree you have. You can't very well take a tree from a 3-5 gallon pot and plop it into 20 gallons of water-retentive soil in a deck planter w/o expecting some limitations.

Coarse soils made of larger particles are unable to hold as much excess water as soils made of fine particles like compost or peat. The excess water held in soils made of fine particles limits root function and growth, which limits the plant. Ideally, the entire soil mass would be damp from top to bottom at container capacity. Container capacity is the measure of how much water is in the soil after the soil has been fully saturated and just stopped draining. If there are several inches of soggy soil at the bottom of the container, you'll have problems.

If you use a soil like the gritty mix that doesn't hold any perched water to speak of, you're unlimited in how large a container you can use - put a cutting in a 55 gal drum if you like. But if you use a soil that holds lots of excess water, you should move up in container size gradually to prevent the soil from being waterlogged for extended periods.

Also, if you're going to 'pot up' you should do it BEFORE the soil/root mass can be lifted from the soil intact. If you wait too long, your root structure will develop problems and become a permanently limiting factor, speaking from a health/growth perspective.

As noted above, periodic rood maintenance (pruning roots & correcting problem roots as well as changing the soil) should be included as a necessary part in your long term care plan.

Al

Has anyone tried growing fruit trees in Rootmaker or Smart pots? Or those Air pots from Europe?

In my experience, fabric pots work very well for a variety of plants, fruit trees included. I trialed Smart Pots in 2012 and was very pleased with the results, but I switched to Root Pouches this year in order to cut costs (I use a lot of pots).

I’m here in the Pac NW too. I began buying/ pot planting fruit trees about 7 years ago, using the pot up method. I usually buy 2 new fruit trees each year. Switched over to Smart-pots / Air Pots 3 seasons ago for my new purchases. The air pots/smart pots have worked out 150% better than regular/old school potting. The rooting/root ball issue doesn’t occur in air pots. Also, it self prunes and keeps my tree sizes in check. I can’t be trying to bring in certain trees in the winter if they have grow to 8‘ , 10’ , plus. If you are ok with full size maturity than fine. But in my situation, I want to be able to harvest fruit easily (low hanging) and basic maintenance is easier done with a smaller dwarf tree that has been kept in check. Btw, my dwarf fuji & dwarf honeycrisp apple trees were switched over to air pots and they fit under the roof overhang. By keeping them in the air pots and by pruning the main stem during dormancy period, I keep them under 8’ and they can get protected from too much rain and frost through the winter. My dwarf meyer lemon tree is only in a 3 gallon smart pot. I can easily move it into my house in late fall. If I had gone the pot up method, I would’ve eventually had to move a pretty heavy pot into the house. I bought a Leprechaun Dwarf Nectarine tree 3 years ago that is frost tolerant so that sits outside all year, here in the Pac NW. It sits in a 20 liter air pot which I think is slightly larger than a Home Depot orange bucket. Since it self prunes/roots, I‘ve never had to do anything. I do basic branch pruning after harvest and I get boatloads of nectarines that I usually give away half of what I harvest away. When it comes to Dwarf Fruit trees, IMHO, air pots/smart pots are the only way to go. Now with my vegetables garden, other than my kratky portion of my plants, the rest I do use the root pouches too and they work great. IMHO, since veggies are seasonal and I grow a lot, the root pouches are a perfect way to go, but for fruit trees since most people aren’t buying a ton of trees, spend a few bucks for a few air pots / smart pots, i think is the better route to go. Best of luck

I realize this post is almost old enough to vote, but FWIW, air pots are not a substitute for root-pruning and do not achieve the kind of root pruning that relieves root congestion; and, root congestion remains as limiting in air pots as it is in conventional containers - probably more so because of superior aeration and gas exchange. Air pots kill the tip of roots only when the roots grow into the dry areas where the sidewalls are perforated or where the soil is dry because of evaporation from root mass perimeters through the material of growing bags. Just as death of or pruning a branch tip forces lateral breaks (back-budding) proximal to the pruning cut, death/pruning of a root tip forces lateral breaks of next order roots proximal to the pruned/dead root tip. Also, you cannot stop older roots from thickening - especially in air pots. As the older roots thicken, they take up space that would otherwise be occupied by the much more desirable fine roots that do the lion's share of the heavy lifting. Just the fact these roots ARE thickening and taking up valuable space is proof enough that air pots do not relieve root congestion; but, they do help somewhat to relieve circling and potentially girdling roots.

Al