Growing English Lavender From Seeds

I'm attempting to grow English Lavender from seed, because I would like to plant a lot of them around our house - approximately 170 - and the seedlings are relatively expensive.  Also, as my friend Jason R. pointed out, I'm Mark Watney'ing - I'm inspired by the book The Martian that I read over the summer.

The main instructions came from the "growing information" section on the Burpee catalog page for Lavender, English:  http://www.burpee.com/herbs/lavender/lavender-english-prod000476.html but I also read through several other web pages, see references below.

Ezekiel 25:17 for software engineers

The path of the righteous engineer is beset on all sides by the iniquities of scope creep and the tyranny of product owners.  Blessed is he who in the name of Agile and Scrum shepherds their project through the valley of deadlines, for he is truly his team's keeper and the finder of lost core functionality.  And I will strike down upon thee with great practicality and furious patience those who attempt to delay our release.  And you will know my name is Victory when I lay my practicality on thee.

With apologies to Quentin Tarantino and Samuel L. Jackson.

And a wall paper version provided by Phil M.