What has the longest bloom time in your garden?

SYinUSA

I appreciate a plant with an extended blooming season. What lasts the longest in your yard (not individual blooms, but the plant as a whole, deadheaded as required)?

My garden is only in its second season so I don't have a good grasp yet on which plants last the longest here, but so far my 'David' phlox started blooming in early March and is still going. My 'Scepter'd Isle' rose had blooms last year from May until November. A 'Creme de Cassis' dahlia lasted from June through October. I love the agastache I have (May through September bloom), but fear for its safety - of the 6 I planted, only 1 survived, and it's not the dwarf variety I thought I planted. It's over 1m tall now and outgrown the front-of-the-bed locale I provided.

On the opposite end of the spectrum, a 'Beverly Sills' iris was very disappointing - three blooms all on the same stem, all balled in three consecutive rainy days. I have a few lilies that only last a week or two at most and need cover for their stems for months afterward. 

Slow-worm

Your poor lilies!
I like long flowering ones too.
Woody salvias - May to November, fuchsias and osteospermum -June till around October, Festuca 'Elijah Blue' grass keeps its seed heads from June until I cut them off in spring, Penstemons mid June to October, lavenders May until autumn, but they still smell gorgeous and look good for a few weeks - sometimes I leave them on.
Castor oil plant flowers in winter - huge white overheads followed by big black seeds until May.

borgadr

I have two plants that flowered for at least 9 of the last 12 months: Erigeron karvinskianus, and Lobelia pendula 'Monsoon' (the latter because we had a very mild winter and it was up against a south-facing wall).

No deadheading for either; just a trim in January. 

Fire

I am the same about wanting very long flowering plants as I have small plots.

• I agree about woody/bushy salvias
• Abutilon Nabob - flowers for most of the year
• Parahebes - with some trimming through the year
• Erigeron
• Sedum Autumn Joy, if happy, seems to go from About May to Nov with deadheading. I Chelsea chop half of it
• Jupiters Beard
• Rozanne - this year flowering from Feb - usually to Nov.
• Dahlias - will go and go, esp if fed weekly
• Cosmos - June to frosts
• Californian poppies can last a very, very long time, if the plant is happy and it is thoroughly dead headed. Last year one red plant flowered socks off from May to frosts
• Heucheras do well and will reflower when cut back
  
• Hellebores go from about Nov to May. I esp. like Corsican types
  
• Diascias can go through the summer
  

SYinUSA

@Slow-worm, the agastache I mentioned replaced some salvias I had that flopped horribly leaving a gaping hole in the center of the plant. It was either 'May Night' or 'Caradonna'. I also realized that they smell like cat urine to me, so I suppose it's just as well they didn't thrive. I've got a couple of fuchsias in hanging baskets that the hummingbirds seem to like, so it's good to know they'll keep on going. Glad that penstemon makes your list, too. I just bought a few that seemed like they'd gone over already but they may recover in time for another flush this year. I've been eyeing lavender in the nurseries lately but I will need to make a new heavily-amended planting bed if I'm to attempt Mediterranean plants. 

@borgadr, I admit I had to look up erigeron. It looks so dainty but sounds so tough! I have always seen lobelia labeled as an annual. Did you expect it to overwinter or was that a surprise? That blue color is incredible and worth reseeding even if it does die back end of season.

Fire

Lavender doesn't bloom long at all.

Fire

Lavender doesn't bloom long at all.

SYinUSA

@Fire - wow, you've given me a lot to look at! Great list.

I guess I should mention the dandelions. I get those practically year-round 

ERICS MUM

Erysimum “Bowles Mauve”.  Described as a perennial wallflower, in my garden in mild East Anglia it flowers year round.

Sheps

For me it's Sanvitalia, flowers for a very long time.

Plant it and enjoy it.

Buttercupdays

Euphorbia 'Fireglow'

Flowers in spring with bright orange/red flowers which gradually fade, but as the colour comes from the bracts it hangs on all summer, until cut down by frost. Makes a good low hedge and wind shelter for other plants too, but you have to control it's spread.