Thursday, December 4, 2014

How to Overwinter Tender Bulbs, Tubers, Corms, and Rhizomes

When I lived down South in zone 7, I rarely ever lifted bulbs for the winter unless I wanted to move them or share them.  I was usually able to get away with piling extra winter mulch on top of tender bulbs and that would get them through, even if they were only hardy to zone 8.

Calla Lily, hardy to zone 8, overwintered in zone 7 with protective winter mulch
Now I'm up North, though, and, sadly, extra mulch just doesn't cut it.  Those tender bulbs (or corms, or tubers, or whatever they might technically be named) have to be lifted and packed away for winter storage and then replanted next spring.  Here are my steps for lifting and storing them:

1.  After the first good frost, cut off the browning foliage and carefully dig up the bulbs, avoiding bruising them.  Gently brush off excess dirt.

Digging up Gladiolus murielae corms
2. Dry in a warm, well-ventilated place for a couple of days.  Corms such as Calla Lily, Crocosmia, Freesia, Gladiolus, Tigrida, and Tritonia need to cure in a warm place for longer, about three weeks.


Sometimes those corms will have lots of little baby 'cormlets' on them.  Just separate them gently from the main corm.  You can keep them for planting next year if you like; they will eventually grow big.

a corm with lots of little baby 'cormlets' attached
3.  If your storage area is humid, you might want to dust the bulbs with an organic fungicide.  (I've never done this, though, since my storage area is thankfully pretty dry.)

4.  Store in paper bags or cardboard boxes filled with peat moss, sand, vermiculite, or sawdust.  Gladiolus can just be stored in paper bags or onion bags, or in a box between sheets of newspaper.  For some tubers and corms, such as Dahlias, Foxtail Lilies, and Rain Lilies, the peat moss or other medium should be very slightly dampened, so that they do not completely dry and shrivel up.

Don't forget to label your bulbs!
Just make sure you don't store the bulbs in enclosed plastic boxes or bags, as that will keep in moisture and cause them to rot.

5.  Store in a cool, dry place, around 40 to 50 degrees.  Check on the bulbs a couple times during the winter.  If the bulbs are shriveling up from dryness, give them a mist.  Discard any bulbs that are getting mushy and decaying.

6.  Plant next spring...

Dahlia 'Kelvin Floodlight'
... and enjoy!


Here are a couple other resources that list how to store different kinds of bulbs:
A.D.R. Bulbs: preserving summer bulbs
P. Allen Smith: storing summer bulbs

17 comments:

  1. Hi, Indie! You remind me of my good fortune that I rarely have to lift bulbs or corms. I do lift my voodoo plant and also colocasia ( elephant ears). The voodoo plant is interesting in that one only has to sit the corm on a shelf; and then when the thing starts growing in the spring, it is time to plant it.

    By the way, you asked about caring for persimmon trees. They are very low maintenance; I do not have to spray them at all!

    ReplyDelete
    Replies
    1. That's good to know about the persimmons! I want lots of fruiting plants in the yard, but I hate taking care of fussy things :) I miss when I lived down South and had lots of rain lilies, dahlias, and glads that I just left in the ground!

      Delete
  2. Good post! I never bother with lifting the corms. If they aren't hardy enough to survive, I either don't plant them or I consider them annuals. I'm just talking bulbs, corms, and tubers, though. I do bring in a few plants for the winter. For a while, some of my Glads reappeared a couple of years in a row, even though they weren't hardy varieties! They were planted near the house on the west side, though, where it stays warmer throughout the winter. Now, if I ever invest in Dahlias, I could see lifting them--they're so precious.

    ReplyDelete
    Replies
    1. That's interesting that they came back! I left a few glads out there, but I doubt they'll survive, as it's been so cold already, but you never know! I don't think I'll plant nearly as many tender bulbs as I used to. I do miss all the rain lilies I used to have, though. I'm thinking of planting them in containers so they'd be easier to move. I'll only dig up so many bulbs!

      Delete
  3. Excellent post and I so want to lift and store mine, but this garage in our new house is not heated so it will get down to the 10s and 20s. The basement is too warm at 60-65...so I still am trying to find the perfect spot.

    ReplyDelete
    Replies
    1. That is too bad! It is hard to find a good spot. The outside wall of our basement stays decently cool, so they will stay there, as far away from our warm utility tanks as possible.

      Delete
  4. I used to lift and store the tender bulbs but it is too much trouble any more. My glads always came back so they stayed in the ground, but I eventually pulled them because they multiplied too much. Th Dahlia, I just use as annuals. Most all that I have are cold tolerant. Every six to seven years I add tulips and allium. It is nice to see what is new each year.

    ReplyDelete
    Replies
    1. I have a few glads still in the ground, so we'll see if they pull through. That would be great, as there are a few varieties I really like.

      Delete
  5. Excellent step-by-step instructions, Indie. I'm afraid I've stopped overwintering bulbs, trying to cut down on tasks as I get old, I mean 'older.' My crocosmia come back every year. P. x

    ReplyDelete
    Replies
    1. Next year I want to plant some crocosmia next to the greenhouse. I'm glad to hear they come back every year so I might not have to dig them up. Planting them next to the greenhouse should keep them a little warmer, too!

      Delete
  6. Welcome Indie!
    Calla is a wonderful plant. I love her flowers.
    In my garden grow only in yellow.
    Dahlias are very beautiful and I have a few varieties.
    Have a nice weekend :)

    ReplyDelete
    Replies
    1. Callas have such pretty flowers. I love the leaves of them too! I had a neighbor once who planted white Calla Lilies en masse, and it was so pretty when they were in bloom!

      Delete
  7. Thanks for the great advice, Indie--every year I have to look up this information. I don't store many bulbs, though, other than caladium, because I know me and know I'll forget to dig them up in the fall:)

    ReplyDelete
    Replies
    1. Yeah, I have only dug up a few. There are a few tender bulbs that I really want to add to the garden that I love, like rain lilies, so I'm debating whether or not I should plant them in containers to take inside every winter or to lift them. I'm a lazy gardener, so containers might be the easier and more optimal thing to do. :)

      Delete
  8. This post reminds me of how fortunate I am gardening in a climate where I don’t have to consider things like lifting bulbs or corms, everything stays in the ground in my garden - and that’s including dahlias and calla lilies :-)

    ReplyDelete
    Replies
    1. That is nice! That's how it pretty much used to be for me when I lived in a warmer climate. But I guess there is a tradeoff - now I can grow some things that like it cooler, but plants that like it warmer require more work.

      Delete
  9. Impressive! I've always just left my dahlias in the ground to rot, since I'm too lazy to dig and store them. Good for you, though, keeping all those tender things warm and safe.

    ReplyDelete

Related Posts Plugin for WordPress, Blogger...