"greg" wrote in message
ps.com...
Hello,

More stupid questions from a completely novice gardener.
We planted a crab apple about a month ago and are not really sure if
it is OK.

A lot of the leaves are crinkly and quite yellow - is it poorly (maybe
over / underwatering? - I've been giving it some water from a watering
can every 3-5 days since we've had no rain recently), or could they
just be the newer leaves coming out?

And how do you tell the difference between overwatering and
underwatering anyway?

Thanks

Not a stupid question at all.
Over watering will give yellow moist leaves which then go crinkly.
Under watering will give yellow dry crinkly leaves.
In other words not a big difference but in your case it looks like you have
not been giving enough water. You did not state in what type of soil this
tree is planted but unless you have good moisture retentive soil then I
guess at the moment you should be watering daily.
I doubt that the tree is a goner but it may be this time next year before it
gets back into a decent growing mode.