Tuesday, 23 July 2013

Shady goings on, aphids, midges and mites, spectacular Darwinian evolution and buttercups to licorice.

Hello Everyone. Here it is,  the usual  mix of bits and bobs in no real order.  Hot weather  here in the UK. My garden is  looking the worse for it.  Everything drooping  and  cracks in the  ground big enough to lose a barrow and an under-gardener down but I can't bring myself to put the sprinkler on.
New postings announced on twitter @pwhorticulture. 

Dobies or Suttons?

Where does your loyalty lie? Would you rather buy your seeds from Dobies ...........

 ......or Suttons Seeds?

Field  Woodrush.

This is a  small woodrush ( Luzula campestris)  which managed to escape the   blade of the lawn mower  and when I bent down to see  what had  had he temerity to  stand up to the whirling mower  blades I saw this fantastically colourful cluster of bristles,stigmas and  anthers on a short  grassy little plant. . And if you were  wondering , yes,  'The anther was  blowing  in the  wind'  

More incey winceys.

I have no doubt that I have said  this in every blog I have written but  when you are working in the garden, even if you have your eyes only half  open,  you will be bombarded by a never ending procession  of  wonderments either visual , auditory  or olfactory. I was trimming a box hedge recently  when there was this tiny explosion of  newly hatched,  minute  spiders  all scurrying away  from, I'm guessing, the protection of  a communal  nest. 

Chelidonium majus. Greater celandine

The Greater Celandine is rather an  exotic looking  UK  native wild flower. It  is a member of the Poppy family whereas the  more common Lesser Celandine which is low growing and a bit of a garden weed and  really looks  nothing like it apart from having a  yellow flower,  is a member of the family  Ranunculaceae,  the  Buttercup family. Both however are in the order  Ranunculales so there is a kind of relationship albeit a bit of a way back in the family tree.
The foliage is light green and  a bit ferny  but really not  like anything else. It  has a lightness and open  style  that makes it very pretty and you feel it would have served particularly well  as an ornamental plant  in medieval times before  more exotic looking plants started arriving from abroad.

The sap turns a  vivid orange when exposed to air  and is variously described as a cure for cancer and a serious irritant but whatever it is  it is certainly  an eye catching colour.


I recently sprayed  some  herbicide  onto some  creeping  buttercup in a lawn and it wasn't until  the buttercups  started dying and  turning yellow  that I realised  just how regularly it was spreading. It  made  a very  definite straight  line  away   from  where it started in the  middle top of the picture. The  stolons (Stolons run above ground,  rooting and putting out  leaves  at the nodes  whereas rhizomes run underground and put up a shoot  from the  nodes.The  rhiza  part of rhizome is the Greek for roots  and will be recognised in the  genus Glycyrhiza  which is  the licorice plant. The name of the genus  comes from the Greek 'glukurhiza', 'sweet root' ( is the gluku bit  the  derivation of glucose?) and this went through, bastardised,  into old French as licoresse and so, slightly less bastardised,  into English as licourice or licorice. The plant licorice is Glycorhiza glabra, a one metre  high  member of the legume family, it is hardy and has pale bluish  flowers and as chance would have it it spreads by  stolons not rhizomes. The root is where the sweetness is.)(That must be the world's longest bracket.) run  across the grass  rooting as they go  and very soon colonise  quite large areas of  lawn.
Back to licorice. I remember eating things called Pontefract cake or,   as the Normans would  have said, Pomfret cakes. which were like  thick but pliant  coins stamped with a  picture or logo  and made out of licorice.  Yorkshire

Herbicide damage.

I have been trying to eradicate Hedge Bindweed (Calystegia sepium), the bane of many gardeners's lives, from a garden and I have been using the systemic herbicide Glyphosate. I was trying  an idea suggested to me   by someone who swears it works but I had my doubts. The idea is to put the spray strength mix of herbicide in a jar or  bottle  and secure it  so that it wont fall over  and then take  as many  bindweed stems as you can and  cut off the tops  and put the ends into the  weedkiller solution. In theory  the  weedkiller gets taken up   through the stem ends and kills the plant. Well. my plants just went  a bit yellow and that was it - not much killing going on. Maybe I need to refine my technique.   What did surprise me though  was that  the following season the Euphorbia griffithii  over which the bindweed was growing showed  classic symptoms of  herbicide damage. I have no idea why unless there  was  a spillage of herbicide at some stage but it does show why you have to be  careful with weedkillers. As well  as  this being a lesson  in  being careful with  weedkillers   I also put the picture up   to show what  weedkiller  damage looks  like. People  have sent me  parts of plants asking me what disease is affecting  their  plant , often roses,  and it has been  herbicide damage not a pest or disease.  

I was having a general poke about on  gardening  blogs when I came across  the  American   Juniper Hill Farm  blog  and what a blog it is too. It is mightily well presented  and there are some very impressive guest writers, some  big names in the garden world worldwide.
But what  particularity caught my eye were  pictures of a garden structure that I had built many years ago and it prompted me to  dig out  some old  pictures of my own from the late 1980s. The structure  was in the garden at Bourton House and was built to provide shade so that a  wider range of ornamental plants could be grown.   Very often  the  shady parts of a garden are in the  dry and rooty soil under trees and shrubs and not conducive to growing  good healthy plants  so we decided to build some artificial shade  from a pattern, with modifications, spotted by the garden owner on a trip to Canada. The garden is in the Cotswolds and   has alkaline soil so we took the chance to  build up some acid soil in the shade house so  an even greater range of  woodland shade lovers could be grown.

A  curious  but  innocent enough  looking garden  feature until, that is, you  go inside on a  sunny day and .......

........you begin to think did someone slip something in my tea at lunch time.
Zig Zag ain't in it.
Later in the evening, as the sun begins  to set, things became a little  more ordered.

What surprised me most was that the structure  is still standing some  twenty odd years on with, as far as I know, no major repair.  


 A discreet member of the orchid family.It is not easy to spot amongst  the  grass because of its green flowers but it is a curious thing  to see  and a  real treat when you  stumble upon it.


At least these aphids had the decency to  be of a colour  that compliments the  host plant, Thalictrum aquilegifolium, that they are destroying.

Aphids 2 
 Black bean aphid, Aphis fabae, on the underside of a broad bean leaf. Aphids are great!They have some interesting life styles. For instance this one  overwinters on the Spindle Tree , Euonymus europeaus and  some Viburnums. Eggs  are  laid on the winter twigs after  winged males and females have  had sex on the winter host plant.    The eggs hatch in late spring and when they mature they fly onto the summer hosts which can be  beans and some weeds such as Fat Hen, Docks and Poppies. Many  wingless young are produced parthenogenetically, ie  without  sex taking place, during the summer. Also during summer  winged  females will be produced  and these migrate to other plants to start new colonies. As  winter approaches winged males are produced and they fly  off along with  winged females to the winter host where they mate and  the female lays  eggs for  the next years generation.  In warm summer conditions each aphid can give birth to several young a day and each young  has young within it. The young aphid matures in a week and starts producing   more young.  It has been estimated that if all  the young produced from one aphid from the start of the summer survived  then by the end of a season there would be over a million tonnes of aphids from just that one aphid. Stand back!   ( I have heard a figure of ten million tonnes in a hundred  days  of breeding in the summer.Whichever is right  either is a staggering statistic.)

Black bean aphids shooting up off the main veins. Aphids  get their protein from the sugary sap of the plants they live on. They  suck up  a great amount of sap to get the protein they need and much of that sugary sap is squirted out of their  back ends  and given the  unduly  charming name of Honeydew. It is this sticky  Honeydew that coats the leaves beneath and  on which the black Sooty Mould grows. Sooty Mould  is often seen on plants with infestations of  sap sucking insects such as scale insects and aphids.  
If you look carefully at  the  picture you will see what  look like white skeletal aphids. These are the shed skins of the aphids which as they get bigger shed several skins  much like snakes do. 
Control  the aphids by  rubbing them off when you first see them and by pinching out the infested tips when beans start to form. They can be sprayed with fatty acids but you need to start early before  colonises  start to develop. Also keep host weeds under control. 

Solar System or Death Star?

I spotted this Allium trying to show how the  solar system was formed or was it  trying to do a 
Death Star  impression? Hard to know. 
Oriental Poppies.
An unreal sparkling glint like crinkled  red  foil. 
 Pink. tissue.

Some of these poppy flowers are huge.

Photo or painting?

Helter Skelter
Our Gardening Question Time Roadshow  marquee was pitched opposite this  fantastically painted, traditional helter skelter at Derbyshire County Show
It looked remarkably flimsy inside. 
Closed for the night. I would have to wait until tomorrow to  get my turn.


This surprisingly aggressive looking  animal skull  belongs to  an animal  that while not  native to the UK  can be found  in the wild in the eastern counties. Any ideas what it is ?  Answer below. For extra points can you tell me whose hands it is?

Peony flowers
Two  little chicks in  a nest of yellow anthers.

Darwinian evolution in action. 

There are three snakes  native to the UK and this is none of them. This is  a slow worm ,Anguilis fragilis, and not a snake at all but a  lizard that  has evolved to lose its legs. It was hiding, along with some snails, under a roof tile at the foot of a wall  and soaking up the heat  radiated  through the tile. 

Its curious how evolution works. The slow worm has has obviously worked out that enough pairs of glasses   have been lost by little old ladies in their gardens that  the best way never to be noticed is  to  make spectacles of yourself.

Daylily Gall Midge

There is a serious pest of daylilies  now well established in the UK and yellow varieties seem more at risk.
The problem is  a small fly that lays its eggs in the  flower buds of Hemerocallis.    

 The buds  become  stunted and distorted. The larvae are small and difficult to see  and by the time they have entered the bud  there is nothing to be done  other than to pick off and destroy the  bud and therefore reduce the  number of  adults for next year.
 The larvae are small, only two or three  millimetres long  but there can be many of them in a single bud. I managed to find nineteen in  one bud  but there can be  more. Using late flowering  varieties can help avoid the  breeding period and therefore  avoid  infestation. Trying to  spray  against the   adults   means timing your spray to hit them before  they lay their eggs which is  a virtually impossible task. Cultivating the soil around the plants will help  birds  find the  adults over-wintering in the soil.

Aphid 3
Woolly Aphid ( Though sometimes seen on cardigans.)

This is woolly aphid on  apple but I have seen  serious  infestations on Pyracantha  and Cotoneaster . It was introduced to Europe from  North America and was  first reported in London in 1787. 
If you  brush away the white, woolly,  waxy protective  coating you will find  brown aphids beneath.
The aphids are present all year round on the plant. Young  aphids  overwinter in  cracks  and galls. Infested plants produce  swellings  which  can crack open. as well as providing  overwintering quarters for the aphids hey also allow in  disease causing cankers and die-back. Control is difficult. Only use  systemic chemicals on  on  ornamental plants and not on edible crop plants such as apple. . Try the  usual  suspects of fatty acids  but be prepared  for a long battle.  

Walnut Leaf Gall Mite  ( but then it  might not.)  

This always looks worse than it is  and the  damage causes little harm to the walnut tree. 

The raised blister on the surface of the leaf is matched by a concave  depression on the  underside of the leaf. There are felt like hairs in these depressions  and the mite lives amongst  those hairs. Plant galls are an interesting  group of 'ailments' and caused by a wide variety of insects on a wide variety of plants. The reactions to  a tiny insect can be quite dramatic.I may have mentioned these books before but they will bear repeating.   The nPocket Encyclopedia  of Plant Galls. Darlington nand Hirons. Pub. Blandford. Out of Print but available second hand. Britain's Plant Galls . Michael Chinery. Pub.Wild Guides

Leaf Rolling Sawfly on roses.

Don't you just love the names given to plant pests and diseases. It is very much  a case of it is what it  does  on the plant. This is Rose  leaf rolling sawfly. It  can affect all roses though some are more susceptible than others. It is caused by the sawfly  probing  the leaves with its saw like ovipositor prior to laying itd eggs. All the probed leaves will curl up but not all will have eggs laid in them which at first I thought was  wasteful but I guess if you are a predator looking for larvae you might find the whole process so  hit and miss that you would give up and go somewhere else.  Can you control  it? Not easily but the larvae overwinter in the soil so cultivation the soil will help expose larvae the the birds.   

Its a whoppa!

I am not a big fan of blousey   Rhododendrons but Anthony , who has  big hands, showed me the   size of this single bloom  on a new hybrid  which he was selling at the wholesale nursery.  

It is the  skull of a Chinese Water Dear. Escapees from country parks have started to establish themselves  in parts of the UK  The teeth are articulated and can be tucked away or thrust outwards. There is a similar but less dramatic  set of teeth on the almost  ubiquitous and pestilential  Muntjac dear.
The  hands holding the skull are those  of Barry Gayton and there is no reason why anyone should know that. He runs Desert World Gardens in Thetford. He  has a dry sense of humour.

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