All cultivars of B. nigra prefer acidic soils. They become chlorotic in alkaline soil conditions.

See if you can find the NDSU variety called Northern Tribute(R) if your concerned about pH.

Pennlake, I'll see if I can source that one.

Where are you located...and have you tested your soil? I ask because Betula Nigra (Betula Nigra) do quite fine in zone 6 central Indiana where the soils are usually neutral to slightly alkaline. The soil in my yard tests just slightly alkaline, and I have a 6 year old straight species River Birch growing very well with not a hint of chlorosis. They can get quite large and are often planted in the wrong location...however they are everywhere in my area and grow well. Many cultivars of red maple and oak get chlorosis here...but not the birches. I always read the same things you did...however I feel they are much more tolerant than given credit for.

Joe, I have not tested. (Southwestern Ontario) Two Sugar Maples I planted 10 yrs ago have mild chlorosis, and a White Oak that went in last spring has yellowing leaves and looks to be struggling this season and will likely be pulled. I assume a ph problem and so wonder about the Birches.

in the states i would suggest you talk to your COUNTY extension office.. as the local peeps would .... offhand.. know local conditions...

do you have any canadian equivalent??

are there any high end nurseries nearby.. or tree farms...

ken