growing cardinal flowers (lobelia)

katob Z6ish, NE PaAugust 14, 2011

One of my favorite plants this year is a dark leaved cardinal flower I bought this spring. I'm into red this year so each flower is like an explosion of red and it definately makes me happy! Plus the hummingbirds love it too.

Does anyone have advice on overwintering? I know the native lobelia cardinalis overwinters no problem but I heard the dark leaved types don't do as well. Should I do anything special? Can I take cuttings or something? or is it as hardy as the plain species.....

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They are short-lived perennials, especially in colder zones, so you may need to save the seeds for winter-sowing. You can also get seeds of the dark-leaved variety "Queen Victoria" from Thompson-Morgan. Another option would be to dig the plant and keep it in the garage over the winter. I've heard of people in your zone doing that for iffy plants.

Here is a link that might be useful: Link to Seeds

    Bookmark   August 15, 2011 at 12:40AM
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I'm guessing those of us in Z5 will find that bringing these through a bad winter is something of a challenge. I bought Lobelia c. 'Fan Scarlet' this year because I was starving for some red in the garden and the red color is absolutely stunning. I've seen the hummer a lot this year too so I sure hope I can keep this plant going. I'm also guessing it's one I'll be forced to overwinter inside, up in the attic since my cellar is too warm when the woodstove is going. Hazzard's sells the seeds (which I may try winter sowing this year) but even they say it's only hardy to Z6. I don't often have zone envy but this could definitely bring on a spell of it.

    Bookmark   August 15, 2011 at 4:21AM
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coolplantsguy(z6 Ontario)

The native range of L. cardinalis extends quite a bit north in Ontario and Quebec, so winter hardiness is not an issue -- easily zone 3.

    Bookmark   August 15, 2011 at 7:44AM
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They are winter hardy, but, from what I have read, resentful of soil disturbance or competition.
But they do reseed, and it would be unusual not to get babies next year. Keep your eye on the plant, the leaf colour, size, shape, etc. so you can recognize the tiny little seedlings next year.

    Bookmark   August 15, 2011 at 9:30AM
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NHBabs z4b-5a NH

The wild types are definitely fully hardy here, since they grow all over the river bank, but I have not had success with garden types in my garden. I don't know if it's a soil issue or that the hybrids are less hardy or that the garden types come from plants that have a less hardy genetic basis.

    Bookmark   August 15, 2011 at 11:02AM
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Mine reseed (or atleast they have done so far) and come back. But its only been a 3 years or so. The red color of fan scarlet is stunning. However mine got really tall and need staking.

    Bookmark   August 15, 2011 at 12:31PM
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roxanna(z5b MA)

here's a non-red perennial that is gorgeous right now in my garden (zone 5b). glorious color for late summer, and overwinters perfectly. late to rise in the spring, so mark location. sorry the photo didn't post, it's a true blue-violet color.

Lobelia x gerardii 'Vedrariensis'Perennial Lobelia A lovely perennial lobelia with violet-purple flowers in late summer and fall. Takes heat and humidity easily. Can be grown in a bog, even submerged part way in a pond. Also grows well in the average perennial bed as long as the soil remains moist. As with other perennial lobelias, be sure to remove the dead/dying crown at the end of the growing season, allowing the daughters (or pups) to grow out and replace the original plant each year.

Blooms: Mid Summer to Early Fall
Pot Size: 3�" Zone: 4-9 Height: 2-4 feet Width: 15-18 inches Flower Color: Purple

    Bookmark   August 15, 2011 at 1:02PM
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hawkeye_wx(z5 east-central IA)

My four native green cardinal flower all made it through last winter very well and are huge this year. My one queen victoria did not make it, so I'd have to agree that it is an iffy perennial in the north. When the snow melted the QV was rotted.

    Bookmark   August 15, 2011 at 2:54PM
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My Queen Victorias also were rotted this spring, but they sure were gorgeous last summer. I bought them last spring at a local hardware store for 99cents each, but they didn't carry them this year, unfortunately.

Monet's Moment (deep pink and larger flower stalks than QV had) came back great though and is flowering at this moment.

Maybe hill up the plants and then protect with straw?

    Bookmark   August 15, 2011 at 6:18PM
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katob Z6ish, NE Pa

99cents each...... I won't tell you how much I paid for my plant, lol, kind of an impulse buy and much more than you paid!

I looked for daughter plants but didn't see any yet, the plant is still blooming though so I guess it has time. I was wondering how the plant would spread.

I might try potting up a few of the "daughters", assuming I get some, and take them into the garage for the winter. The mother plant will get mulch and I'll hope for the best.... on the plus side it's only a few inches from a clump of hardy bannanas that has made it through the last 2 winters with no protection.

Do seedlings bloom the first year? The dust they grow from doesn't fill me with optimism as far as my indoor seed skills go so it will need to be an outdoor sowing.

and thanks for all the responses!

    Bookmark   August 15, 2011 at 9:36PM
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tepelus z6a SW MI

I think Queen Victoria is only winter hardy to zone 7, which would explain why all of the zone fivers on here don't have any luck keeping them alive over the winter. I tried it once a long time ago when I was a zone fiver (I'm still marginally a zone fiver, but considered on the zone map a zone 6a), and it didn't come back the following year. However, the species ones come back for me every year and reseed, and my purple one, gerardii 'Vedrariensis', don't seem to produce seed, but do increase quite quickly in size year after year and can make divisions from the clumps.


    Bookmark   August 16, 2011 at 8:51AM
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terrene(5b MA)

I have several patches of Lobelia cardinalis, most of it started from seed (winter sowing and self-sowing). They like to reseed in moist bare earth, and I'll find little seedlings in odd places and often in the garden path. It makes a small rosette of foliage the first year, and then grows quickly and blooms the 2nd year. It gets better each year. So beautiful and just about the favorite hummer plant in the garden.

    Bookmark   August 17, 2011 at 4:44PM
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I was surprised this year see i have some white cardinal plants. So either one of my red cardinal or the blue cardinal flower changed to white. But now I have all three colors together and it is quite nice. And yes the red and blue plants are the lobelia variety.


    Bookmark   August 21, 2011 at 3:42AM
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leslie197(z5 MI)

Kato, take heart - with some luck your dark leaved lobelia may survive zone 5 winters. They are also worth replacing once in awhile.

I had a stand of Queen Victoria Lobelia going for around 10 years in my zone 5 "wet garden" on very heavy clay. They were planted at the bottom right side of our small hill along a drainage swale that often flooded for weeks during the spring. The area would dry out as the season progressed (at least on the surface). The lobelias were late risers and did not seem bothered by the early periodic flooding or the somewhat drier conditions during their actual growth and bloom periods.

I used these dark reddish leaved plants to balance out some small reddish leaved shrubs on the opposite drier side of the yard, since I could not find a cheap red leafed shrub that could live in these conditions.

I started with six good sized (& expensive) plants one spring. When five of the first six overwintered, I added six more the following year. After that I added three plants every couple of years. There was always some loss, but some self-seeding and eventually a really good sized clump was developed that many non-gardeners assumed was a multi-stemmed 5-6 foot shrub. Fortunately, despite their height I never had to stake them, though they leaned some.

I did nothing special for these plants. The existing clay soil where they grew was rich enough with nutrients, but extremely dense and unworkable. Planting holes were hacked out of the clay with no amendments added to them. No fertilizer was ever used on the plants. EXCEPT that as the garden aged I dumped more and more chopped leaf litter on top of the area in the fall.

Eventually, the area became clogged with thicketing shrubs and became shady (and drier). A lot of the water-loving perennials were crowded out or removed by me. I still find an ocasional dark leaved lobelia or Japanese primrose growing there, but I'd have to hack my way through the shrubbery to reach them.

    Bookmark   August 23, 2011 at 10:30PM
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Lobelia cardinalis is listed as hardy to zone 2. Unfortunately it has 2 opposing requirements: moist in summer but dry in winter. So it dies with a speed of light in zone 7 or 8 in wet winters. Nearly nobody can keep it alive here in Denmark zone 6.

    Bookmark   August 24, 2011 at 6:03AM
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The only problem growing them here in the west, is meeting their requirements of lots of sun, PLUS lots of summer water. We can manage the sun, but here in the desert called California, all summer water must provided by the gardener, not on 'occasion' but consistently. Al

    Bookmark   August 24, 2011 at 9:37AM
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I have also found L. cardinalis hybrids to be short-lived. I had a stand of a beautiful purple form for three years, which after a hard winter and wet early spring diminished to a single plant. I added plants of "Fan Scarlet" to the same spot (a local nursery was selling three-packs for $1.95) and it's a knockout, well worth replacing by seed or other means whenever it dies out.

    Bookmark   August 24, 2011 at 11:00AM
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flora_uk(SW UK 8/9)

When I tried them the problem wasn't overwintering. The snails scoffed them before we even got to the end of the summer. I wish I could grow them.

    Bookmark   August 29, 2011 at 1:30PM
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gottagarden(z5 western NY)

I have lots of different lobelias and they are easy and reliable. Except for queen victoria (red leaves) which didn't overwinter.

I bought a fried green tomatoes lobelia this year (dark leaves) which is supposed to be zone 5 hardy, so ask again next year :-)

    Bookmark   September 3, 2011 at 7:17AM
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ontnative(5b Can/USDA 4)

My most reliable ones have been Fan Blue, Compliment Deep Red and the native Lobelia siphilitica (great blue lobelia)

    Bookmark   September 5, 2011 at 7:54PM
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katob Z6ish, NE Pa

I'm finally seeing a couple of sprouts coming up for next year's plants! I almost lost hope. Now I have something to dig up and save over the winter.... hopefully it will work out.

I already have visions of a larger clump, more bloom stems.... we'll see how it goes. I'll probably wait a month or so until I dig it up (let it get a couple hard freezes first)
hmmmm. As long as I'm digging something up I bet I could fit a couple tulip bulbs into the open spot :)

    Bookmark   October 14, 2011 at 9:38PM
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I have mines living next to the outside faucet in full sun, so it gets dripping from the faucet. Once established, it actually somewhat drought tolerant, but I usually keep it water a bit. The plant has spread to a good size clump and seems to come up every year. The good thing about Chicago area winter is that it's usually pretty dry and the summer can be pretty well (unless there is a drought).

This year, I have gotten some hummingbirds as customers. Too bad it didn't come earlier when more of it was blooming.


    Bookmark   October 16, 2011 at 8:42AM
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terrene(5b MA)

Weislaw, I'm perplexed why Lobelia cardinalis can't overwinter in your country? It is certainly zone hardy and in its native range it is an obligate wetland plant, which means it's well adapted to deal with wet soil. And we don't generally have dry winters in much of the eastern United States.

Paul, now that the hummers have found you, they will probably be back next year. Apparently they often come back to the same gardens and feeders year after year.

    Bookmark   October 17, 2011 at 9:13AM
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dandy_line(3B (Brainerd, Mn))

I successfully overwintered some L.cardinalis the past two years. I remove the seed heads over time except for what I want for new generations.

    Bookmark   October 20, 2011 at 1:03AM
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What has your experience re the amount of shade lobelia can tolerate (ie and still flower)?

    Bookmark   October 20, 2011 at 6:56AM
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terrene(5b MA)

My back gardens are growing mostly in open woodland, so basically all of the perennials are growing in partial shade. I save the sunniest spots for annuals and veggies.

The Lobelia cardinalis does great in about 3-4 hours of sun a day, with rich well-drained soil. Every year it reseeds and I plant another new patch somewhere. It's growing with other wetland plants, and I water regularly if there is a very dry spell, but that hasn't been lately. We've been getting tons of rain. Hope that doesn't mean lots of snow this winter again. :(

    Bookmark   October 22, 2011 at 11:21PM
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katob Z6ish, NE Pa

I'm surprised no one has commented on that picture.... what a planting! The hummingbirds must fight over that spot all summer

    Bookmark   October 24, 2011 at 7:53PM
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Terrene, I have just read that Lobelia cardinalis is not considered hardy in England zone 8. See the link.

Here is a link that might be useful: Lobelia cardinalis in UK

    Bookmark   October 25, 2011 at 8:12AM
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terrene(5b MA)

Hi Kato, thank you for your comment! I actually have more Lobelia cardinalis than what's in that picture. It is happy in that garden, reseeds a lot. I give some away too. And yes the hummers do tussle over this plant all the time. The resident hummer will "guard" it, but the others sneak in for some nectar. It's their favorite, although they do like Salvia 'Black & Blue' which I grew this year for the first time.

Wieslaw, I am still perplexed as to why it is difficult to overwinter this plant in the UK? It has a large range in the eastern US, is very cold hardy, as well lives in zones with much milder winters. Very curious.

    Bookmark   October 27, 2011 at 6:00PM
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katob Z6ish, NE Pa

If it ain't broke don't fix it.

It was such a long fall I apparently had too much time on my hands. I was still able to do things outdoors in December so I dug up the lobelia and brought it indoors to the unheated garage.(I was going to forget about it and hope for the best) For a while it was good but then about January I noticed it was starting to sprout.... not cold enough apparently. So I moved it next to the compost pile and some potted chrysanthemums, covered it all with mulch and crossed my fingers.

I just checked up on it yesterday. Mice had eatten every last tiny bit of root. Ironically enough had I never dug it in the first place there's a good chance it would have survived. We had around a zone 7 winter this year.

The chrysanthemums are also gone. It looks lke mice dug through those pots too. All of this is about 10 feet from a shed which has been a cat house all winter. Great job guys.

    Bookmark   February 24, 2012 at 7:30PM
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terrene(5b MA)

Sorry to hear about your Lobelia. Are you sure it was mice and not voles? I've never heard of mice eating plant roots. Now you've made me wonder about the 2 pots of Salvia 'Black & Blue' that are overwintering in the garage (that I had forgotten about). How warm is your garage? I'm surprised it is warm enough to cause the perennials to break dormancy.

    Bookmark   February 25, 2012 at 12:51AM
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flora_uk(SW UK 8/9)

terrene - if you follow Wieslaw's link you'll see the reason L cardinalis is so temperamental for us. "Needs damp summers and dry winters and, therefore, dies in UK winters." We can certainly provide damp summers but a dry winter is inconceivable. It's the wet, not the cold, that gets them (as with so many lovely plants we struggle to grow). I tried it once - total failure through snails and damp.

    Bookmark   February 25, 2012 at 5:37AM
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terrene(5b MA)

Yes, I had read the link Flora, but am still having a hard time wrapping my head around that because we don't have dry winters here generally. In New England, they are wet and cold. The cold is a damp bone-chilling cold. The current winter excepting that is! The dry and mild winter we're having this year is not the norm.

Kato, I check my Salvia B&B in the garage yesterday, and it's sprouting too!

Anyway, we had a very blustery day yesterday, gusts were probably in the 50-60 mph range. I look out and see half my huge beautiful Black Knight buddleia blowing across the front yard. The vole has been eating at the roots and the wind blew it loose. Aaackkkk! That's the last straw!!! The cat doesn't hunt in the front garden because I don't like her near the road. I stopped over at a friends this morning and borrowed his mole trap.

    Bookmark   February 26, 2012 at 11:22AM
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katob Z6ish, NE Pa

I pray it's not voles that I have. I think i was mice because I found a little nest and the roots were exposed enough (I dug it up kinda sloppily) so that after eatting the rosette of foliage the mouse could suck up the roots like little tasty strands of spagetti.

The garage can warm up on a decent winter day.... the furnace and water heater are in a side room that vents to the garage so that adds to the warmth. It probably stays in the 40's.

Ok the fig tree I keep in there is starting to sprout now too. I wonder if I can put it somewhere colder.... I already put all the potted bulbs outside, I gave up on winter.

Terrene: open up one of their tunnels, put peanut butter on a trap and cover it with a board or something... if you can catch a few dozen it might make a difference. (from someone who was shocked one spring to find a mature cherry tree dying because it's roots were completely girdled and stripped)

    Bookmark   February 26, 2012 at 2:56PM
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dandy_line(3B (Brainerd, Mn))

Has anyone tried 'neutering' the Lobelia, ie, dead heading to remove all the seeds? I think they must exhaust themselves with seed production which is why they have trouble surviving. After I did that, they survived just fine in my z4a climate.

    Bookmark   February 27, 2012 at 1:36AM
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Here in California we have wet winters (this year excepted) and lobelia cardinalis go through the wet winter very well. If we provide enough summer water and lack of competition they do well in the garden. The queen Victoria is not as robust a grower as most Lobelias. Al

    Bookmark   February 28, 2012 at 9:47AM
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I do not ubderstand. My Lobelia is planted where it gets wet feet in the Autumn, winter and spring. It is very dry there in the summer most of the time unless we have a very heavy rain. The very opposite of the link. It also gets afternoon shade. Here is a picture of mine this year. It seems to really like this spot. I have to say that it is next to a small drainage ditch. Maybe 6-8 inches deep. Maybe mounding it is the answer. Finicky little buggers : /

    Bookmark   July 28, 2013 at 2:55AM
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a2zmom(6a - nj)

I planted the straight species in 2010 and Queen Victoria in 2011. Its come back every year with no problem including last year which was a very very winter with a lot of tempertaure flucuation.

Here's a picture from August 2011.

Behind this planting is a birch tree, so it's in a fair amount of shade.

    Bookmark   July 28, 2013 at 5:35PM
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