Provence lavender lay-in (W.I.P.)

This has been my first real opportunity to paint in over a week. It has been really hot, muggy weather lately, so I've decided to stay close to the studio and scour some of my old photo archives for landscape subject matter. In doing so, I came upon some of my images of an area of Provence that I visited in lavender season almost 10 years ago (!) called La Drome Provencal. Here's a 16x20" composition I've mapped out:

I have more to flesh out in terms of both shadow/highlight and detail, but I've started with a basic block-in to nail down my composition. Up to now, I've used the same color palette as the previous painting I posted of Lake Como. But when I started to lay in the lavender I had the overwhelming temptation to reach for a cooler, more transparent red (like alizarin crimson) to add some brilliance. I have held off up to now.

What I aim to see is if I can acheive the proper color relationships in the painting without having to resort to any other colors than the three primaries I've chosen. Alizarin Crimson (permanent) has long been my default red when I paint in a single primary palette. While it is a beautiful transparent color, I sometimes feel it is almost too garish in my mixtures.

So I feel it is worthwhile to try and acheive a luminous, vibrant quality to my paintings without having to resort to over-the-top color. Being somewhat of a color slut, this is not an easy challenge for me! We'll see if I can hold out to the bitter (better?) end!