Length: 14¼ km (8.9 miles). Toughness: 1/10
10:52 Crewe train from Euston, changing at Watford Junction (arr 11:13, dep 11:18 from Platform 11; be quick!) and arriving Garston at 11:23. If you don't trust West Midlands Trains to make this connection you'd have to take the 10:24 Birmingham train, arriving WJ at 10:44. [From south or west London you could take the 10:16 Southern train from Clapham Junction, arriving WJ at 10:58].
There are two stations in St Albans for the return journey. From the main (City) station there are fast Thameslink trains at xx:27 & xx:57 and slower ones at xx:07 & xx:37. If you want to return via Watford Junction, trains from the Abbey station are hourly at xx:41.
Tickets on the two lines are not interchangeable. However, an off-peak single to Garston is now pretty cheap as this line is included in the new fare structure (off-peak single = half price of return), so buying two singles is not as disadvantageous as it used to be. [And it's now cheaper to buy two singles even if you're returning from St Albans Abbey.]
Every now and again I feel like giving an outing to a classic walk which has become neglected. This one has had regular midweek outings in December but very few on a weekend; its last Sunday posting was 7½ years ago. I thought a procession of walkers into a cathedral city would be particularly appropriate on Palm Sunday, although you'll probably need to acquire a donkey from somewhere if you want to be greeted by cheering crowds waving palm branches.
The suggested place for a pub lunch is the Moor Mill Beefeater, after 6¼ km. There are some watering-holes further along in the next village (Park Street) and of course plenty of refreshment places in St Albans itself. The Cathedral is well worth visiting; if you're too late for its Abbot's Kitchen Café (closes 4pm) there are other places nearby which stay open later.
In normal circumstances ground conditions in spring ought to be better than December, but after the recent monsoons don't be too surprised if you come across some muddy woodland paths and squelchy meadows. Note that if the riverside path into St Albans is still blocked you'll have to follow a diversion; this is covered in the directions on the L=1.7 page.