Larkspur are generally annuals, delphiniums are perennials even though they are finicky and don't come back for all.

Larkspur do have finer leaves and smaller flower spikes that are thinner around.

I have found that larkspur reseeds very well for me, and I also collect seed and scatter it around. I had no luck with delphiniums coming back, so I definitely prefer the larkspur.

Becky

I thought true larkspur (Consolida) was an annual.
Which delphiniums are you trying that don't come back? I have a row of Pacific Giants. There is something about one spot where the plant frequently doesn't come back...I've yet to determine what it is.

i found over the years.. that perennial delphs are very borderline z5 .... i never figured out if it was temps .. or root rot in damp winter soil ... or mid-winter thaws ... or what not....

larkspur is an annual in z5 ... which reseeds freely.. but not overwhelmingly ... and frankly the only version i will grow.. like you say.. that intense blue flower is something else ...

buy it once.. have it forever ...

delphs just got too expensive to replace year in and year out ...

I THINK .. the key to perennial delphs would be soil structure and drainage .... as well as micro climate.. but that is a WAG ...

ken

I just had a thought. Maybe I could dig up the delphinium and store it in my garage, then replant in spring? Like I do some others. Has anyone tried this?

I have put a rather thick mulch on the delphs in fall to protect them from my Zone 4 temps. It didn't seem to matter.

Had to look up what WAG meant! My husband says the correct phrase is SWAG!

swag..

stolen w/o a gun???

Southern Women Aging Gracefully

Still Wondering and Guessing

and a lot of other insulting ones ...

lol

though i prefer this one

Strong Wise Accomplished Gentlemen

just plant the larkspur.. and save your money on expensive foo foo delphs ...

on the other hand.. if money is no object.. and you like to fool around pushing the boundaries of zone ... knock yourself out ...

ken

Here is a link that might be useful: link

I would not mulch delphs, they are sensitive to crown rot. I read in an old garden book from the 50's to put a bit of sand on the crowns during growing season, so that the water drains from the crown. It works well for me. My delphs can take a lot of cold, what kills them is poor drainage. They do like moisture during the growing season as long as it is well drained. Larkspur are easier, they do reseed quite well, so once planted you don't have to replant, they are easier than delphs but just as pretty in their own way, I think. Hope this helps........

what about delphinium in zone 7? I bought 3 last year, this year two came back and are looking beautiful right now. The local Lowe's also had a sale on them a few weeks ago--$19 pots for $4.75. I bought 3. They are doing ok though I'm watering them every day due to the intense heat and sun we are having here.

I will try the sand around the crown thing, but should I expect to have to replace them each year in my zone? Thanks

Ken, why did you mention pushing the boundaries of zone? Most delphs are hardy to zone 3, and some even to 2. Most of my delphs are 20 years old, and have survived all types of weather...high and low temp., dry, and wet. I never water them--the only care they get is weeding 2x/year...I don't even have to fertilize.
Several delphinium varieties don't like a lot of humidity, so those of you in a humid climate might just need to try a different cultivar. Also, some are less tolerant of extremely hot temperatures.

Yes, Delphiniums are cold climate plants. It's the heat they can't handle.

I grow the low growing perennial delphinium, Delphinium grandiflorum. Doesn't need staking and is less fussy about growing conditions. I just add some sand to the planting hole.

here's a picture from 2009, cutivar is Blue Butterflies:

{{gwi:237514}}

perhaps.. in relying on a common name.. we are not growing the same delphiniums ....

i would love to see a pic of a z3 delph .... and know its full latin name ...

regardless.. i suggested its is probably not a zone issue.. as much as a soil issue.. supported by hpny who suggests crown rot ... which for me means damp soil in late fall going into ground freeze.. causing the crown to rot at soil thaw in spring .... and also complicated by freeze/thaw in mid winter when there is not sufficient snow cover ....

20 year old delphs simply amazes me ... congrats ...

ken

I haven't taken a picture of them since the digital age, maybe I'll remember in July and post a picture.

But, I'm 5'5", and they're taller than me. They're D. elatum.

And I should have said that most readily available, in the trade, delphiniums are hardy to z3.

I love delphs but they never return for me. In the past I've gotten the very tall ones that need staking. They are so gorgeous! BUT, I'm not rich so I gave them up. I can't spend that much on what should really be considered an annual.

I grow several varieties from seed. Delphiniums are short lived for me. I have one King Arthur which is five years old but most survive 1-3 years. They are easily grown from seed by winter sowing and some will bloom the same year.

I've had 2 of 3 Delphiniums for 5 years. They were grown from seed from a local friend and she thinks they were Magic Fountains, which are a dwarf variety. I say 2 of 3 because this year is the first year that all three did not come back, just 2 of the original 3.

My soil is clay that has been amended to some extent. When we planted them, we also added new soil and amendments to the hole. I think these plants are amazing because I've never had delphs live this long before. Ususally, in our area, they seem to last about 3 years tops, and then they just don't come back.

The gardening friend who gave me these plants says that she thinks that growing them from seed makes them hardier and more likely to return. I love them and I'm happy to see them return every spring. Mine are blooming right now.

Linda

In my experience, delphiniums only start when I seed them in late winter in the dark - Never had them seed on their own like larkspur does, which I'm sticking to from now on - so much easier. The delphs that come back the best are the ones that are in the driest area (Soil and sunlight is the same for the different groups) - These actually bloom twice during the summer while the others struggle.

I think they are short lived and do not like more southern gardens. They like cooler summers and lower humidity. Or move to England.

Since being introduced to D.tricorne, I feel a delph revival coming on. Have ordered seeds of D.trollifolium and have the frankly bizarre D.requienii growing alongside the usuals. I must also put in a mention for the bone hardy (Z4) yellow D.zalli or semibarbatum.

This post was edited by campanula on Tue, May 13, 14 at 12:17

dbl post

This post was edited by campanula on Tue, May 13, 14 at 12:16

It's always cracked me up to see US catalogs marketing "bred in NZ" delphiniums as "heat resistant". No commonly inhabited part of New Zealand has summers with an average high temperature over 80F. In other words, you'd have to go to the Atlantic coast around Cape Cod or north of Boston to find a part of the Continental-climate US with summers as cool as the very hottest parts of NZ. Maybe upper Michigan too. (of course I discount the obviously cool-summer Pacific coast...national catalog merchants obviously see them as a blip that marches to beat of its own drummer)

That being said I bought some supposedly heat-resistant variety at Groff's Plant Farm in Lancaster Co. back in 2012, and it has been perennial since then, in spite of the hellish summers of 2012 and 2013. Blooms and everything! Hasn't really increased in size though, which I think is telling. I'm sure it doesn't like it here.

EDIT: Actually I just double checked my spreadsheet: I have an odd note that I tried "'Stainless Steel' or 'Moonlight Blues'?" in 2011, and it died that summer. Maybe I couldn't remember the cultivar name? Early 2011 was worse for me than 2012. Then I bought something else in 2012 which has survived until now and bloomed both years but alas I lost the tags from that year so I don't know which one. 2013 was actually not a bad summer other than being too wet for some things. The summers of 2010, 2011, 2012 were the really bad ones.

This post was edited by davidrt28 on Fri, May 16, 14 at 11:09

David i dont know why u think NZ hottest would be 80F..we have lots of summers with 32c (90F) and delps grow very well here but still prefer partial shade from hot afternoon sun.

Not sure this was worth bumping an old thread for...but here goes...

https://en.wikipedia.org/wiki/Auckland#Climate

I did say average high in summer. If there's an appreciably warmer, muggier city than Auckland - do tell. Sure it gets hot there sometimes...so does western Europe and the UK. It's still a mild, maritime climate in the final analysis. They are not really bred for our kind of heat. FWIW the one doing OK for me finally petered out...I suspect some of the ones sold here are a genetic mix including some annual or shortlived species.

lol..u did say average...auck is definately humid..but alexandra in the SI can get temps of 37C.. Iv found the fountain delps and pacific giants do really well for me..just got some from the ukraine so they'll be interesting..partial shaded of mine in summer do well..only found this thread cos i have no idea the diff between larkspur and delph and was trying to find out lol

Well I'm not going there to find out but I suspect when any location in NZ gets to 37C, its a dry heat partly fueled by katabatic winds. This is still less irritating to alpine/european perennials than our 2 month summer steam baths.

Part of the problem with comparing climates in this way (plant related) is the most useful information often isn't readily available. Hi and even lo temps are only part of the story. Dewpoint temp standard statistics...mean, 90th percentile values...morning and afternoon...would really be more illustrative. Likewise average rainfall...which doesn't reveal ours comes in huge, plant menacing clumps unlike your more reasonable pattern of sporadic showers. (Might not be true everywhere there...but more like the UK than SE US at least)

A friend gave me some of her Larkspur seeds and I threw them around the garden last fall (southern NC). What a surprise - now it's the first of May and they are wonderful, wonderful, wonderful. They are coming up in the peonies and roses so nicely. It's been a pretty cool rainy spring so far this year. So, will the summer heat kill them off? If they die off in June in the hot sun will they come back next spring? What do I have to do to have them every year? Should I stake them in all this rain we're having?

Mine seem to bloom and then dry up when it gets very hot. But, they always reseed heavily, coming back the next year. I haven't had to plant larkspur seed in years, one sowing and they'll come up year after year. This is the first year I am planting larkspur seeds in many years, only because I wanted lavender larkspur, and my reseeded plants are always purple.

Thanks! Good-it sounds like an excuse to cut out more grass.

I have always been a fan of delphiniums but this season (South Pacific - New Zealand seasonal time) I tried larkspurs for the first time.

still dream about growing delphs, but I gues right now I couldn`t come up with the requiered TLC

but what I read so far is that cultivars/ stock makes a huge difference.

in the big box stores you often get D Pacificum-Hybrids (seed grown)

Karl Foerster bred D elatum-hybrids. As their parents range in the European mountains and country site they should be somewhat hardy, my favourite German nursery declares them to be z5.

Those are propagated by divisions or some kind of cuttings, not in the lab,

so, the botanical name would always help to pin down the differences or good cultivars...

I grew NZ elatum from seed that I ordered from NZ. They have survived for at least four years in my MN Z 4 gardens. I moved this fall so will not know if they survive longer.

I planted 4 'black knight' delphiniums (D. elatum hybrids) in 2016, the 2 near where my down spouts drains, where the soil is more eroded and the mulch washed away, survived. The others rotted over winter.