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When to deadhead Agastache plus advice on a new variety?

NollieNollie Girona, Catalunya, Northen Spain.Posts: 5,668
Hi folks, two in one query:

1. Most of the original flower spikes on my A. Black Adder are now pretty much over and a few new buds are developing underneath. I would like to deadhead to encourage more buds and a fresh flush of flowers. My problem is, the bees are still swarming all over, trying to extract every last drop of nectar from the few remaining flower tubes! Should I deadhead now to encourage more flower spikes for me to enjoy and the bees to ultimately have more to feed on? If I leave them until they are totally brown, will the plant think it’s all over and not bother to produce more for me and the bees?

2. Whilst I like Black Adder, the colour is quite subtle (more lilac than the desired purple). It’s also grown really tall so I plan to move a few plants right to the back of the border. Can anyone recommend another brighter one for a middle border position? I was thinking Blue Boa might work, does anyone grow this and what’s the colour like? It looks blue on some websites and pinky purple on others. I definitely don’t want a pinky one!

Many thanks.


  • Mark56Mark56 Windsor, BerkshirePosts: 1,653
    edited August 2018
    Hiya Nollie,

    I would deadhead if they are mostly done flowering on the spires, this way the energy of the plant will go in to the new buds. 

    My Black Adder is also much paler this year and a less striking purple, I’ve put it down to the intense sun. My one in half shade is more vibrant. Yes, I grow Blue Boa too. It is a slightly shorter variety with deeper purple flowers. I will try to get a picture later. The tubular flowers are longer which means only carder and certain bumbles with long tongues can gain access to the pollen, I have observed this recently.
    My Black Adder plants are buzzing with pollinators. 

  • Hampshire HogHampshire Hog HampshirePosts: 330
    My Black Adder got off to a very slow start this year (semi shade) and is only just coming into flower for the first time I also lost some plants which I put down to the wet spring.
    "A society grows great when old men plant trees whose shade they know they shall never sit in."
  • NollieNollie Girona, Catalunya, Northen Spain.Posts: 5,668
    Hi, thanks @Mark56 I was hoping you would reply! Ok, I’ll get out early to beat the bees - moving around in the border is quite a perilous occupation at the moment - perhaps leaving a couple of the fuller spikes for them to be getting on with. BA is very popular with the pollinators here too, so I won’t be disposing of any of the plants, just shuffling them about. A pic of your blue boa would be great, always difficult to tell true colour on the net. 

    Sorry to hear that @Hampshire Hog,  I think I am in the process of losing a few of my young echinacea tangerine dream to root rot - heavy summer rain and humidity in my case.
  • AnniDAnniD Posts: 9,624
    @Mark56, l was interested in you mentioning how much paler your Black Adder was this year, l thought it was just mine ! I lost the one in the back garden after the winter, but the front garden one is more sheltered, so although it looked a bit battered, it survived. The bees do love it. Like Nollie, l'd be interested  to see a photo of Blue Boa.
  • LynLyn DevonPosts: 19,912
    I’ve only got 4 different Agastache, the giant Hyssop types in white and blue, they are about 4’ in all directions, ( I think they will be taller next year.) all from one seed! I’ve got a tiny one grows to only 2’ called Lavender as that is what it smells of,  and the Apricot Sprite. All grown from seeds. I love them and they are all covered with bees. 
    Gardening on the wild, windy west side of Dartmoor. 

  • AnniDAnniD Posts: 9,624
    @Lyn, l grew one from seed called " Sangria", just coming into flower (pink) now. Taller than l was expecting, but hopefully they will start flowering away and become another bee magnet !
  • LynLyn DevonPosts: 19,912
    @AnniD they are like my blue and white ones. 
    Gardening on the wild, windy west side of Dartmoor. 

  • AnniDAnniD Posts: 9,624
    Don't think it was the name that attracted me...... B)  
  • Mark56Mark56 Windsor, BerkshirePosts: 1,653
    Did your Apricot Sprite survive outside Lyn? 

    Mine too Anni, I think it was the constant wet rather than the cold despite aiding the drainage. One survived though :smile:

    They are wonderful plants, everyone should check out the Kudos series - I have Mandarin (orange) and Coral,  both are reliably hardy and have different scented foliage. 

    It’s bucketing it down outside but this is the most accurate colour photo I could find: 

  • NollieNollie Girona, Catalunya, Northen Spain.Posts: 5,668
    I also have an A. Aurantica called Tango, which is a subtle orange and quite small, only about 40cm. The bees and butterflies much prefer the Black Adder though.
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