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Has anyone successfully overwintered fully double nasturtiums?

13 years ago

Hi all! I just ordered Hermine Grashoff from Select Seeds, and I am already thinking about how am I going to overwinter this nasturtium if it makes it through the season. Any ideas? I keep reading you can take cuttings, but then everything I've read about cuttings is fairly difficult-- like misting them every 20 minutes for 16 hours/each day/4 weeks kind of thing that no one can do without a set up. I know nasturtiums are perennial in their own area, but inside isn't the same as a greenhouse kind of condition. I was hoping someone has had some luck with overwintering nasturtiums that could give some tips. Any ideas?

Comments (12)

  • 13 years ago

    what am i missing here...

    how does one overwinter an ANNUAL ...???

    kinda goes against the definition of the word itself ... if it over winters.. isnt it a perennial????

    joke aside.. we need to find out if it is actually a perennial in its native habitat ... and go from there..

    but i am too lazy to goggle for you ... and while you are at it.. find out if it comes true from seed ....

    once you find the latin name.. then add 'propagation' and find out how to propagate it.. how to root it .. or jsut save the seeds ...

    ken

  • 13 years ago

    Hi Julianna,

    "I keep reading you can take cuttings, but then everything I've read about cuttings is fairly difficult-- like misting them every 20 minutes for 16 hours/each day/4 weeks kind of thing that no one can do without a set up."

    Taking cuttings of annuals isn't that difficult. Instead of misting, just use humidity domes. They can hold the moisture in for up to two weeks, which is usually plenty of time for the cuttings to have developed enough roots to survive on their own as plants that don't need any special support. These is a picture of my zinnia cuttings under humidity domes three years ago.

    {{gwi:18188}}
    And this is a picture of my zinnia cuttings taken to save them from frost this last October.

    {{gwi:24475}}
    The humidity domes are reusable for years. I use a soilless growing mix (Premier ProMix BX plus extra added Perlite) to root cuttings in and I use Dip-N-Gro as rooting hormones. Zinnias are prone to bacterial rot, so I use Physan 20 as a bactericide. I don't know if Physan 20 would be necessary for nasturtiums. There can be very little fuss: just put the cuttings under the humidity domes, turn on the lights, wait 11 to 14 days, and remove your rooted plants.

    ZM
    (not associated with any product mentioned)

    This post was edited by zenman on Mon, Dec 31, 12 at 23:23

  • 13 years ago

    Hi all, and thanks.

    Yes, they are perennial in their native habitat. They do not seed and have to be propagated vegetatively. I know the Latin name and have already spent several hours researching this. Google is exhausted which is why I posted here.

    Zenman-- yes, maybe with the right fungicide and bactericide.. you're right. The sources I read specifically mentioned to not dome them, but I assumed it was because of rot and you're spot on about that. This may be the best option. It takes about 4 weeks for them to supposedly begin to root. I think it's the long time coupled with the bacteria and such.

    I was hoping someone had done it since these nasturtiums are so expensive (relatively speaking compared to the regular seed-propagated ones). Select Seeds has the lowest price I've seen at 6.95/plant plus shipping. I'd love to order Margaret Long from Avant Gardens but at $13 plus $17 shipping, I figured I should try to figure out this cutting and overwintering business and experiment on Hermine Grashoff first!

  • 13 years ago

    Oh! I forgot to include the Latin name for anyone who didn't know-- Tropaeolum majus.

  • 13 years ago

    I have never overwintered Nasturtiums because they self sow for me and I am happy just to have the singles which are not sterile and produce copious seed. But they do root very easily wherever a stem touches the ground so I don't think they will be difficult to root in propagators such as Zenman shows, or even in water. Just ensure you take pieces with a leaf node and give them lots of light. You could do them in late summer before frost and then keep them over winter in a cool, bright place with air movement. A glass porch should be sufficient. As long as it doesn't go below freezing they should survive.

  • 13 years ago

    couple thoughts ...

    you can avoid a lot of 'cures' .. by avoiding stuff first.. i sterilize EVERYTHING ... including the media.. PRIOR to starting the project ... everything gets washed down with 10% bleach.. and the media is temp sterilized 'see link] ... you avoid a lot of bugs and disease.. once you insure you arent starting with them ... and i dont care what the bag claimed.. do it yourself ...

    second.. though zen has this all in front of a window.. i am pretty sure.. that is a heat mat.. to keep the media warm ... 24/7 ...

    things do NOT root freely in cold media ... and what you have to think about there.. is how cold the house gets at night ... the plants cant spend 12 hours in a wonderfully warm greenhouse.. and then night in a fridge ... you have to maintain approx'ly 70 degree media ... plus or minus ... round the clock ...

    its all much easier.. on a plant stand.. especially for those of us in colder zones.. you can manage heat and light easier ... if you can control a variable.. you can beat it.. rather than having 5 grey winter days in a row in MI in jan/feb .... and then you are suicidal.. and the plants commit such ...

    ken

    Here is a link that might be useful: link

  • 13 years ago

    Hi Ken,

    "i am pretty sure.. that is a heat mat.. "

    Good eye. That is a heat mat in the second picture. It is thermostatically controlled, with the sensor poked into the tray, off-camera. However, the humidity domes do develop considerable warmth from exposure to sunlight. The heat mats come into play mainly at night.

    ZM

  • 13 years ago

    Thanks guys! I think I will start trying to take some cuttings in the late spring/early summer. Reason being, nasturtiums generally melt in our summer heat and humidity (as do humans :) ). If I put them in a set up in my south-facing dormer which keeps about 70-80 in the summer consistently, then I can begin some experimentation. I may eventually have to bring the whole plant in for the summer then put it out in the fall. What fun is it if you can't experiment, anyway?

  • 13 years ago

    julianna - I'm curious as to when Nasturtiums bloom for you. If the summer is too hot and you can't overwinter them what is their season in the garden? For me they are a summer long annual which dies with the first frost but self sows. 70 - 80 is a boiling hot summer day temperature here. Is that 'cool' for you? Are these plants really worth the effort against such odds?

  • 13 years ago

    Hi Flora! Well, truthfully? Probably not worth the effort, but as they are one of my favorite flowers I still try. :P Nasturtiums here will grow from March until early June, then they peter out and sort of either languish until autumn or die. We have (June-September) most days in the mid to upper 90s, and several weeks where 100s are regular if not entire weeks with 100s. Meanwhile, humidity is high: 70-90%. 70-80 would be cool and nice.

  • 13 years ago

    I guess I should mention that my balcony is north-facing and recessed though. It is bright, but I have very little direct sunlight. This saves most of my plants, actually. I have good luck with partial sun plants because they prefer relief from the mid-day sun in such climates. I get more sun off my railing which is where I put nasturtiums, herbs, and strawberries (Mara des Bois)-- about 4 hours or so, still shaded in the middle of the day.

  • 13 years ago

    Flora, I'm in zone 9, several hundred miles south of Juliana. We plant nasturtiums in about October here, and if they don't freeze they'll bloom until about March or April. But a freeze usually gets them. I usually have some in my front yard and some in the back yard, which is on the north side of my house, and the ones on that north side don't survive a freeze, but the ones on the south side (front) will. They will die when it gets hot, though. We grow petunias this time of year, too.

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