Mary's Veggie Garden

January 31, 2012

Onions Compared: Copra vs. Patterson

Filed under: Gardening,Onions,Root Cellar,Vegetables — marysveggiegarden @ 8:35 pm
Tags: ,

Onions drying 3 days after harvest: L-R Copra, Cipollini & Patterson

Copra and Patterson are both hard, yellow storage onions.  The catalogue describes these two hybrid onions as similar in hardness and storage qualities but with Patterson being slightly larger than Copra.

Here is how they compared in my garden.


2011 Number Harvested Weight of Harvest Average Size Ounces  Storage Quality
Copra F1 79 13.75# 2.8 oz.  Excellent
Patterson F1 82 19.5# 3.8 oz  Very good

The numbers say it all: Patterson produces a bigger onion than Copra when grown in identical conditions. Both varieties produce onions with a range of sizes and the smaller Patterson onions are the same size as the larger Copra’s.


To me, Patterson and Copra taste about the same. I’ve enjoyed them lightly sautéed and stir-fried,  and roasted whole in the oven.

Copra onions from storage 1/26


Copra is the clear winner.  None of my Copras have sprouted yet, though a couple of the Patterson have sprouted. Even though sprouting is not a big problem with Patterson, it is not keeping as well as Copra. The depressed areas in the picture below indicates something is going wrong under the skin and the picture of the peeled onions shows the problem.

Patterson onions from storage 1/26

Patterson onions from storage

I can’t blame this problem on my less than ideal storage conditions, because the Patterson onions were showing signs of this problem back in October and November.  A couple of the Copras may have the same problem, but almost all the Patterson onions are affected.

Growing Method

Onions in the garden 6/25/2011

3/6/2011 Started seed, indoors, under lights

4/14, 4/15 Transplanted Copra 4/14 and Patterson 4/15 into opposite sides of the same bed at Vassar Farm, separated by a row of red onions. Mulched with shredded leaves. Watered when needed with a soaker hose looped through the bed.

7/31 Harvested, then dried.

Root Cellar Storage

After curing, the onions were stored in old mesh onion bags hanging from nails in the basement. After the outside temperature dropped below the inside temperature, sometime around mid-November, I moved the onions into the ‘root cellar’, whose temperature drops much lower than the basement.

Because I don’t have any way to hang the bags in the root cellar, I piled a bag of Copra and a bag of Patterson together in a plastic 5-gallon bucket. My intent was to leave the lid ajar by a couple of inches, but  I’ve forgotten occasionally, and the humidity in the bucket got high enough for the Copra onions to start growing roots. This has not yet affected their keeping ability.

The lower temperature in the root cellar has been good for the Copra onions. Last year many of them were sprouting by Feb. 1, but this year, with lower temperatures, there is no sprouting.


  1. What a great experiment and comparison! I don’t think either of those onions will do well here where I’m at. In fact most long term storage onions don’t do well here at all, being usually long day types that do better in the north. But I keep trying different ones to see what happens

    Comment by maryhysong — February 13, 2012 @ 8:41 pm | Reply

    • Yes, both of these onions are long day length ‘northern’ onions. The big, sweet short day types are generally disappointing in the Hudson Valley and they must be eaten first as they are not keepers.

      Last year I froze some of my onions when they started growing. I should have double or triple bagged them; the smell permeated the freezer. I think they also lost flavor in the freezer. Storing them in my root cellar, which is colder than the basement, has solved the sprouting problem and its a better solution.

      I suspect there are other Alliums you could grow to fill the slot for onions in winter cooking, perhaps a good plot of leeks.

      Comment by marysveggiegarden — February 14, 2012 @ 8:14 am | Reply

  2. Hello
    I am an organic produce farmer in PA (originally from Poughkeepsie :)) and am wondering if you had trialed any other storage onions like Pontiac.
    Mike Nolan
    Earth Spring Farm

    Comment by Mike Nolan — November 1, 2013 @ 7:55 am | Reply

    • I grew Pontiac in 2012 – see . Although I promised a storage comparison, I think we ate those onions quickly because of their thick necks.

      2012 was an unusual year in that I had difficulty storing a lot of my onions. For the first time ever, I lost about a third of the Copra in storage – the tops never folded over before harvest, just died back. Cabernet did very well last year and is also doing well this year. Cabernet gets large and has a shorter growing season than Copra. It could be that weather conditions in the 2- 3 weeks between Cabernet and Copra harvest was a problem for Copra last year.

      My 2013 selections are Cabernet and Copra. Both are storing well, with Cabernet doing slightly better than Copra. Cabernet is purple, with a really tight skin & excellent flavor baked with a roast.

      Comment by marysveggiegarden — November 1, 2013 @ 9:40 am | Reply

  3. Thanks for a really informative and helpful post about these two varieties. I’m trying both Copra and Patterson this year, and your comments about their storage capabilities will help guide what we use first and what we store longer.

    Comment by Steve Wood — June 27, 2014 @ 11:13 am | Reply

  4. I would give Patterson another chance at long term storage. I’ve grown them for two years in a row. Last year’s crop lasted until April when we ate the last one. This year’s crop is holding up very well (Jan 8). My storage method is pretty simple: mesh bags in an unheated pantry.

    Comment by Ed — January 8, 2015 @ 1:27 pm | Reply

    • Perhaps our growing conditions are different, giving different results with Patterson.

      I’ve grown Cabernet several years now and they store very well, particularly for a red onion. My yellow onion is Cortland, which is also storing very well. Some of the Cortland onions were huge, with thick necks. I used the big guys last fall cooking pizza sauce and chili ’cause I knew they wouldn’t store well.

      Comment by marysveggiegarden — January 8, 2015 @ 4:56 pm | Reply

  5. Patterson is slightly larger than Copra and tastes better as compared to the latter but the thing is that the Copra surpasses the Patterson in terms of the storage quality and that is why most of the people prefer them.

    Comment by Laylah Paterson — October 8, 2015 @ 3:37 am | Reply

  6. I tried growing Patterson last year (2019) in Kansas with good results. I thought that might be interesting as Patterson is considered a Northern variety. I started the seed indoors and transplanted to the open garden later after the last freeze. Will be interesting to see how that works this year.

    Comment by vern — December 30, 2019 @ 2:59 pm | Reply

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