With apples and pears your usually lucky. Since a lot of growing for the “industry” happens in the Netherlands (and i guess Belgium to?)
So most likely when not specified, a weaker rootstock has been used. (due to their mass production for industry, weaker growing rootstocks are cheaper)
if i had to guess, id say your apples might be on M9 or maybe M26.
Pears likely on quince C or Adams or A (kwee)
Most likely your pears will have a bit more vigor than your apples. Since the likely rootstocks for pears are more vigorous than M9 for apples.
Your soil on the picture looks quite dark (do you have loam or clay soil?). So if i guessed correctly on rootstock. Your spacing seems just about perfect. (although depending on soil, if your apples are on M9, they might lack a bit of vigor to completely fill a multi layer horizontal espalier of 2 meter wide/high. You could let them grow a little less wide. and make the pears a little wider)
I would warn against buying fruit tree’s without knowing the rootstock though. More so for plums/cherries than apples/pears. Since the more commonly used (cheaper) rootstocks for plums/cherries are way more vigorous and tend to make quite large tree’s. You likely want to know how large those get before planting.
Unfortunately it is becoming a bit of a trend here that fruit tree sellers no longer know or specify the used rootstocks. It’s getting harder and harder to find ones who do.
I have no experience with either of the nursery’s you linked.
Could you look at your Williams pear? Does it have 2 grafting spots?
If i am not mistaken, Williams has some compatibility issue’s with quince (kwee) rootstocks. It’s best for pears that aren’t compatibly to have an inter stem. Although not all nursery’s do this or know to do this. If seen more and more pear tree’s without an interstem. It can take a few years to “show symptoms”. And at that point most people don’t know what happend or won’t go back to complain. So business wise i guess it makes financial sense to not take on the extra expense to graft an interstem. I’m not saying your tree lacks an interstem (hard to judge from picture, and i don’t know the nursery) just saying it’s a possibility.(looking at the picture. there seems to be a graft union (bud graft) just below the horizontal. Where the main stem has a slight “bend”. If that’s the williams graft union. Some of the lowest side branches could be of the interstem. You could leave one of those side branches. On the picture they don’t look like quince. But it’s hard to judge from a zoomed in picture online) If you leave some of the bottom most branches (or shorten them) you can see what the leaves look like and than prune in spring. Then you would know more. Or if you can find a clear graft union very low, then it’s highly likely an interstem has been used.
The doyenne is fine. Doyenne is used as an interstem and has good compatibility.
I would not buy tree’s if the seller could not tell me what rootstock was used. And in the case of pears if it had an inter-stem or not. But i might be a bit extreme there. And it gets harder and harder to find sellers who know those things.
I can highly recommend de on line catalogus - boomkwekerij de linde
I always wanted to visit / see his nursery. But just found out he is retiring soon. Although the nursery is still open this year (and hopefully next year to)
I got lucky a few years ago, when he had enough customers in the Netherlands to drive there. And he delivered some plants. The plants where excellent. Although he sometimes delivers (if he comes near you or you don’t live to far away) as far as I’m aware, he doesn’t ship tree’s by post.
He specifies rootstocks. Uses interstems where necessary for pears. And has a large amount of rare and disease resistant varieties. I’m really sad we’re loosing such a good nursery. Although i certainly think he has earned his retirement.