The ST-225 does not auto-park.... therefore, yes, park the heads before shutting down your system.
Some will tell you it is ok to not park the heads, and yeah it is ok to not park the heads sometimes
BUT, usually I will do that if I'm working on a system on the bench and can't otherwise park the heads because of lack of boot, etc. and will be rebooting right away anyway. Even then, I will always make sure the heads are parked at the end of the session before putting the drive away on the shelf.
In the interest of preserving vintage drives and prolonging the life of the platters, it doesn't hurt to park your heads. It would be a good idea to keep a parking utility on your drives so there's always one available. I use park.com which I think came with spinrite.
Here is a handy chart from the Seagate ST11 manual that shows auto-park info for each drive model:
MFM models:
================================================== ===========
| Model | Formatted | R/W | Data | Sectors | Auto- |
| | MBytes | Heads | Cylinders | per Track | Park |
================================================== ===========
| ST124 | 21.4 | 4 | 615 | 17 | No |
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| ST125 | 21.4 | 4 | 615 | 17 | Yes |
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| ST138 | 32.1 | 6 | 615 | 17 | Yes |
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| ST151 | 42.5 | 5 | 977 | 17 | Yes |
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| ST225 | 21.4 | 4 | 615 | 17 | No |
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| ST251 | 42.8 | 6 | 820 | 17 | Yes |
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| ST252 | 42.8 | 6 | 820 | 17 | Yes |
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|ST4053 | 44.5 | 5 | 1024 | 17 | Yes |
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|ST4096 | 80.2 | 9 | 1024 | 17 | Yes |
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RLL models:
================================================== ===========
| Model | Formatted | R/W | Data | Sectors | Auto- |
| | MBytes | Heads | Cylinders | per Track | Park |
================================================== ===========
| ST137R| 32.7 | 4 | 615 | 26 | No |
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| ST138R| 32.7 | 4 | 615 | 26 | Yes |
-------------------------------------------------------------
| ST157R| 49.1 | 6 | 615 | 26 | Yes |
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| ST225R| 21.2 | 2 | 667 | 31 | No |
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| ST238R| 32.7 | 4 | 615 | 26 | No |
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| ST250R| 42.9 | 4 | 667 | 31 | No |
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| ST277R| 65.5 | 6 | 820 | 26 | Yes |
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| ST278R| 65.5 | 6 | 820 | 26 | Yes |
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|ST4144R| 122.7 | 9 | 1024 | 26 | Yes |
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