Grapevine Dormancy

Grapevines go dormant (go to sleep for the winter) following harvest. The timing of dormancy varies depending on location. Our estate vines here on the winery property and most grapevines in North Central Texas are harvest from late July to mid-September depending on variety. They usually enter dormancy between November 15 and December 15. One knows that dormancy is achieved whenn all of the leaves have fallen from the vines and the shoots are no longer green but brown. Once the leaves have fallen and the shoots are brown, the nutrients and water have migrated down the trunk into the roots beneat the surface of the ground. This offers protection from freezing until spring. Grapevines requires very little maintenance during dormancy, especially nutrient or herbicide and insecticide maintenance. However, there are two very important mainenance activities:

1. Pruning. This is critical and in North Central Texas, the timing is very important because pruning too early can stimulate bud break and as stated above, we want to avoid early bud break because of late spring freezes. Once the vines are dormant, we prefer to wait until late February - early March to prune. 
2. Sufficient water supply. Although grapevines do not need as much water during dormancy, it is possible to have periods of drought. It is important to monitor soil moisture and irrigate if the roots do not have adequate access to soil moisture. 

Sometimes in Texas we have warm days in the early spring (late February - early March). When this happens, it is possible to have early bud break and then a freeze in mid to late March that can destroy the primary crop for that year. Some varieties can still have a secondary bug break, but it is usually much less productive than primary bud break (10% to 40% of normal crop load). Normally, early spring freezes do not kill the vines. This, however, is possible if the freeze is severe (temperatures less than 15 degrees F).

Lost Oak Estate Wine Grape Varieties

I first saw this 52 acre property in 1995 and was fortunate to find out that it was for sale before it was listed.  I loved the slope of the terrain and the soil type (Sandy clay loam).  Wine grapes do not like “wet feet”.  They like fast draining soils like sand or rock (not heavy clay).  I got permission from the owner to do a soil percolation test and the rate (how fast the water drains down through the soil) was excellent.  I looked up the region and found that it was in the Cross timbers Ecoregion 29D which was described as excellent for agriculture. I then worked with my Real Estate friend Rob Orr to purchase the property. 

We planted our first estate vineyard here in 1998. This was the same year I retired from Alcon.  We planted eight different varieties because I wanted to find out which varieties did best in this climate and soil type: Chardonel, Shiraz, Leon Millot, Chambourcin, Gewurztraminer, Muscat Canelli, JS12-428 and SV5-247. These vines made up a total of 12 rows (about ½ acre).

In 2004 we planted our second Estate vineyard on the back of our property (about 2.5 acres) and here we planted more Shiraz and Chardonel and 4 more varieties: Ruby Cabernet, Malvasia Bianca, Tempranillo, and Blanc Dubois.  

Two years later (2006) I planted our third vineyard which was ½ acres of 100% Lenoir or Black Spanish.

I definitely learned what did well and what did not do well.  Shiraz and Blanc Dubois did beautifully.  Although the Chardonel did well here I decided to eliminate it in favor of the other two varieties because it was less well known to our customers and it mainly served as a good blending variety.  I ripped up the poorer performing varieties and have been replacing them for the past 6 years with Shiraz and Blanc Dubois.  All total we now have 3.5 acres of these three varieties on our Estate property.

Then in 2008, I made a deal with a former Alcon colleague who owned property on FM 917 (about 6 miles south of our Estate property).  He wanted an Agriculture tax exemption and I needed to plant more grapes to keep up with our growth.

I studied Viticulture, but my real education came from experience (messing up over and over again!) I had great consulting help from Dr. George Ray McEachern and later from Fritz Westover and I must say that all in all I am very proud of what I have been able to accomplish.

I had no idea how little control one has over the outcome each year.  Late freezes, hail storms, tornados, high winds, no rain for months, and new critters.  By the way, wine grapes are not susceptible to COVID -19.

Blanc du Bois is a Winner