Mary's Veggie Garden

February 16, 2015

Onions in Storage: Cabernet, Cortland, and Copra

Filed under: Vegetables — marysveggiegarden @ 8:23 am

Currently I have three onion varieties, Cabernet, Cortland, and Copra, which I’ve stored in the basement since their harvest last August. Last week I needed lots of onions for a big batch of bean soup, so I took some photographs to show how well each is storing.

2/9 - oops, one of the Copras has a sprout.

2/9/14 – oops, one of the Copras has a sprout.

Copra is the gold standard for onion storage, thus this sizable sprout surprised me.

Both Copras are drying and forming a new layer of skin.

All the onions continue to dry and form new skin.

Slicing the onions open reveals that both the Cabernet and the Cortland are forming sprouts, as shown by their greenish-yellow centers. The other Copra still looks dormant.

I’ve grown Cabernet for several years and my experience is that they will sprout before Copra. I’ve been using them for all my cooking since early December and they’ve had green centers since mid-January but so far only a couple have actually sprouted.

Both the Cabernet and the Cortland onions have sprouts forming.

Both the Cabernet and the Cortland onions have sprouts forming.

I grew the Cortland and Cabernet, starting them from seed 3/8/14. They were transplanted into my garden at Vassar Farm May 7&8, much later than usual, because snow melt (and other delays) meant the community plots were not available sooner. Cabernet is an early onion; its harvest finished 8/8, just before I started harvesting Cortland.

The Copras were a gift from my garden neighbor. His mail-order onion plants were transplanted a few days after mine and we harvested at the same time. When he offered a hand-full of Copras I took them so I could do this comparison.

Cortland onions drying in a shaded area of my deck Aug. 20, 2014.

Cortland onions drying in a shaded area of my deck Aug. 20, 2014.

The Cortland onions were medium to very large and the largest had thick necks. Several thick-necked Cortlands show in the picture above.  Thick necks don’t dry well, so the onions don’t store well. I used the big, thick-necked Cortlands first, in Chili for the freezer.

When I bag up the onions for storage, I give each a good sniff. Any that have a smell won’t store well. Fully half the Cortlands went into a bag labeled ‘Use Me First’  but very few of the Cabernet onions joined them.

Which stores better? Overall I think Copra is still the winner, but Cortland is a close second. Remember that half the Cortlands did not go into long-term storage. But that also happened with some of my neighbor’s Copras which were also huge and thick-necked.

Cabernet onions are dependably thin-necked. They don’t store quite as long, but almost all of them can be stored.

For the record – the area of my basement where the onions, potatoes, carrots & celeriac are stored is currently at 39°F near the floor and 42°F  three feet above the floor. That is excellent for storing root crops.

The temperature outside is -10°F (-23°C) as I write. I think this is the coldest day we’ve had in a decade; however when I was growing up (a half century ago), there were a hand-full of days every winter when we walked the half mile to the school bus stop in below zero temperatures. My yard resembles Norma’s . My raspberries still need pruning, but my garden gate has been frozen shut since mid-January; but that doesn’t matter now because only the tips of the brambles show through the snow.

Eventually spring will come, probably faster than any of us expects. I start teaching Vegetable Gardening A-Z this Friday, and maybe by the time I get to Root Cellaring  five weeks from now, I’ll be able to excavate the Lutz beets currently buried under 2′ of snow.

If any of you live in Dutchess County, please join me on a trip through warm, sunny gardens past. Details are under Vegetable Gardening A-Z on the right side bar.


  1. Good review of your onions. I wish I could grow a good storage onion, but I haven’t found one for our latitude. I am trying a couple of new ones this year though, and even the sweet onions keep for several months.

    Comment by Dave @ OurHappyAcres — February 16, 2015 @ 9:57 am | Reply

    • Latitude makes all the difference. Though it looks like Cabernet should do well in your latitude.

      Comment by marysveggiegarden — February 16, 2015 @ 10:38 am | Reply

  2. Thanks for the interesting comparison!

    For some reason I have trouble growing actual onions in the SF Bay Area. I can grow garlic like crazy, but leeks and onions are my downfall.

    Comment by Lisa and Robb — February 16, 2015 @ 10:07 am | Reply

  3. Great looking onions Mary, and a great side by side comparison. I’ve grown copra for several years, but haven’t been real happy with the size I was able to get from them. This year I’m trying two new storage varieties (for me) from seed…Yellow of Parma and Australian Brown (which has nothing to do with Australia). Thanks for posting this!

    Comment by Dan — February 16, 2015 @ 10:43 am | Reply

    • Usually the Copra are medium sized, which works well for our meals for two. In 2014 they were surprisingly large.

      Comment by marysveggiegarden — February 16, 2015 @ 11:25 am | Reply

  4. We store our onions in the garage and our winter has been so warm and mild that we are having sprouting issues as well with our Candy onions. But like yours the Copras seem to be holding up well!!

    Comment by Stoney Acres — February 16, 2015 @ 1:06 pm | Reply

    • Where my garage is too cold to store onions – the snow has not melted off the snowblower in a few weeks.

      Comment by marysveggiegarden — February 16, 2015 @ 2:31 pm | Reply

  5. Hope the Cabernet you gave me do well in my garden.

    Comment by Norma Chang — February 16, 2015 @ 7:35 pm | Reply

  6. I really enjoy seeing others compare traits of the different varieties they grow – well done! I grew Ailsa Craig, Copra & Rossa di Milano this year – all from seed. It was my first time growing onions & I ended up having unforeseen issues with onion maggots. Because of this, I ended up freezing about half of the onions (those with obvious damage).

    None of the Ailsa Craigs were frozen as they are a sweeter onion, so they don’t store as long anyhow & we used them up first. Both the Copra & Rossa di Milano’s in dry storage are holding up really well – I have only had one of the Rossa’s sprout on me so far. I’ll be growing all of these again in the coming year – this time making sure to cover the beds with netting as soon as I plant them out.

    Comment by Margaret — February 17, 2015 @ 9:24 am | Reply

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