Winemaking. Life. The Dirt. Alison Crowe is a Winemaker Based in Napa.

Winemakers Love April Showers…. but Only Before May Flowers

Cloudy skies and rain this week don't pose a problem- it's OK for grapevines to have April Showers before May Flowers (grapevine bloom).

Cloudy skies and rain this week don’t pose a problem- it’s OK for grapevines to have April Showers as long as it comes before their May Flowers (grapevine bloom).

4/6/18, Napa CA

An early April “Pineapple Express” is upon us, having rushed into the North Bay as of last night, providing a steady rain through today, Friday, into Saturday.  I was tasting with a client yesterday and he asked, as we swirled our Pinot Noir glasses, “Isn’t this rain going to mess stuff up in the vineyards?”


My short answer was, “No, not really.”


The reality is that we’re still in need of precipitation in Northern California and, even though it might slow down work in the vineyard for a few days, we still need to replenish our water tables and top up ponds and reservoirs.  I chatted up our Senior Viticulturist, Rich Schaefers, this morning on the way to the office and he agrees with me; we need the rain and since the new clusters haven’t begun bloom yet in Napa and Sonoma, we’re not in any danger of losing developing fruit that way.


The danger comes when the rainclouds depart, leaving clear skies and frosty temps overnight.

The danger comes when the rainclouds depart, leaving clear skies and frosty temps overnight.

This has turned out to be a very warm storm, so we’re not going to be bulking up the snow pack (and in fact, may be melting some), which increases flooding hazards for downstream Sierra foothill communities.


The real danger for Northern California vineyards, however, lies not with flooding (so far) but with the frost that comes when the warm storm front moves through and is replaced by clear, cold nights.  Bud break started a few weeks ago and so tender young shoots and leaves are well pushed out and will continue to be vulnerable to frost damage until sometime in May when night time temperatures rise consistently above freezing.

So no, a few April showers aren’t going to worry me, because my “May Flowers” (grapevine bloom) aren’t on the horizon for another few weeks.  Rain during bloom can be a big problem because raindrops can prevent causing a dramatic reduction in crop and uneven set.

So far so good.  These cooler days have put a halt to what looked like a super-early budbreak last month, so in my estimation the start of HArvest 2018 is tracking more “normal”.  I expect to start harvesting Pinot Noir for rose wine the last week in August.  Harvest?  Did I just say that?  It’ll be here before we know it!


Alison Crowe is an award-winning winemaker living in Napa.  She is the Winemaker for Garnet Vineyards, Verada Wines and Picket Fence Vineyards in addition to sundry other branded and bespoke wine projects.   Alison is also the author of The Winemaker’s Answer Book , enjoys tennis and horseback riding and loves the green grass Springtime rains bring.  Special thanks to Senior Viticulturist Rich Schaefers for contributing his thoughts on this topic.

Twitter and Instagram:  @alisoncrowewine



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