select query on Dates stored as varchar

I have a table (transactions) with an order_date field that is varchar(32).
The data looks like this:

order_date

-------------------

20100623 02:16:40

20100623 04:32:41

20100625 04:18:53

20100625 07:53:24

In my current database (8.1.4) if I run

select (*) from transactions where order_date > '2010-06-24';

I get:

count

--------

2

I'm moving to a new server that has 8.2.11. There, if I run the same query,
I get

count

--------

4

In both, select (*) from transactions where order_date > '20100624'; returns
2.

The newer version does not seem to know that '2010-06-24' is a date the same
way that '20100624' is.

Any ideas? Is there somewhere that I can specify that with, or without the
hyphens, they are both dates?

Thank you,

Yosef Haas

yosef(at)karatedepot(dot)com