Archive | Pests, Problems and Health

Pests, infections, disease, cultivation and growing problems

Disappointing but not Surprising Moss Problems

Yorkshire has suffered an exceptionally wet autumn culminating in disastrous floods at Fishlake and around the river Don. One plant that will thrive in these wet northerly conditions is our old friend Moss.  As this has been covered before I am just using this post to link you to other observations and tips about moss.

Gardeners Tips

Liverworts are a relative of moss as is the green lichen on theses trees.

Moss is a dense low growing mat of greenery that affects badly drained lawns. It is too short to be cut by a mower but a lawn that itself is cut too short can attract moss instead of grass. Feed the lawn with a weed and feed fertiliser or use lawn sand containing a moss killer. Scarify and improve drainage by forking over the lawn. Moss can absorb nitrogen dioxide and  fight against air pollution


Fine Ferns and Damp Moss

I am not a great fan of ferns as I live too near moorland that shares its bounty with gay abandon and I spend significant time removing uninvited guests. These are usually Bracken (Pteridium aquilinum) or  Buckler-fern (Dryopteris
dilatata) with fronds that are arranged like a shuttlecock. There are some exceptions such as the Hart’s tongue (Asplenium scolopendrium) and the  Maidenhair Spleenwort (Asplenium trichomanes) shown in this wall. The strap like fronds  and pinnate rectangular leaflet fronds make a simple  feature on this mossy wall.

Ferns Favourite Locations

  • Due to the microscopic airborne spores British species of ferns can grow in many unusual places such as rocky habitats.
  • Woodland ferns such as Dryopteris species are easy and accommodating in the garden.
  • The striking Osmunda regalis aka The Royal Fern prefers a wetland area.
  • There are several ferns suitable for ground cover and a selection can be found  on the native fern website





Plum Rot and a Rotten Crop

From this to this 

With clear blue skies and good blossom spring 2019 started so well for my plums. But then many things began to  go wrong. The first disaster was a snap frost that did for my Victoria blossom. Fortunately another variety of plum flowers a bit later, is better sheltered and survived unaffected by frost. That didn’t save the crop from the fungal attack of ‘brown rot’.

More on Plum Problems

  • Plum fruit infected with Monilinia laxa have grey coloured pustules. This fungus can also be responsible for end of stem wilt.
  • Plums infected with Monilinia fructigena have pustules that are buff coloured.
  • It looks like I might be blessed with both fungal infections.
  • Brown rot survives on mummified fruit and small cankers on the tree. It passes quickly on to other fruit in the cluster particularly in moist weather.
  • There is no spray available to gardeners so I will have to improve my hygiene and collect up and burn or bury deeply all infected twigs and fruit.
  • Unhappy with previous years crops I had invested in a new victoria plum tree  and I will hope for more success in years to come.

Stingers in the Garden Get Me Nettled

I was picking the Czar plums to make more jam when a wasp was disturbed from eating it’s lunch. Wasps go for my plums just as they are at their sweetest best. My problem was I couldn’t see which plums had a wasp in the fruit if they were above head height or facing away from my hand. The resulting sting set me on the trail of other stingers in the garden.

Plants Stingers

  •  Who has not been stung by a common nettle or the stinging nettle  a herbaceous perennial aka Urtica dioica. More likely to be stung walking on country paths or unkempt areas not in your garden I am sure!
  • The nettle family are stinging plants with  hairs on  leaves or stems that are capable of injecting formic acid that cause pain or irritation. Brushing bare skin against the leaves causes initial pain with the potential for more effects caused by histamine, acetylcholine and other chemicals that are also present.
  • Giant hogweed  contains a corrosive sap that causes severe rashes,  burns and even serious eye damage if you get the photosensitive chemicals  in your eyes . aka Heracleum mantegazzianum.
  • Poison ivy & its cousin, poison oakone is a noted rash-maker. It’s toxin, urushiol oil, is in the sap of the plant and present in minuscule quantities in some other food stuff.
  • Other plants, often those with hairs or irritating sap, can cause irritation and allergic reactions. I suffer with some verbascum Optunia cacti and euphorbia.





Enemies of Roses That Affect You

I do not want to start by worrying you but I am probably going too anyway! After an early summer of brilliant rose displays the down side is the number and volume of enemies our roses are having to contend with.

This is Nothing New

  • I am borrowing heavily from the National Rose Society publications including the title of this post ‘The Enemies of the Rose.’
  • The national rose society’s handbook on the insect, pests and fungus  of the rose was first published in 1908 – over a century ago.
  • My copy is the third edition from 1952. I can’t find a more recent edition nor current reprints. Old copies surface at secondhand booksellers and are crammed with over 150 pages of problems.
  • For example the contents include a virtual dozen references to a variety of different Sawfly but I get ahead of myself.
  • The evils of modern publishing have created a digitised Kindle 2012 edition (? scanned?) and it may be worth the 99p down load but it seems at variance to the older books.
  • The collective brains of an Entomologist, Zoologistand an expert in Cryptogams have been combined with 110 years of horticulture experience and specialist knowledge.

Picking Out Some Rose Enemies

  • I will not try to paraphrase or emulate the original record but will pick out bits worth further exploration.
  • Fungi and bacteria are classified as ‘Diseases’ and insects and sundry creatures as ‘Pests’.
  • Sadly developments over time plus health and safety worries have made many of the cures, potions, treatments, unctions, chemical controls and interventions illegal, outdated or unobtainable.
  • I am not sure whether Defra, European Union and sundry Ministries such as Agriculture  should be classed as ‘The Enemies of the Rose.’
  • Bad health in what ever form is potentially just a sign of a rose failing to achieve the growers ideals and aspirations.
  • Setting standards is essential but being able to cope with the consequences of weather, breeding, growing conditions and external influences can all be enemies of roses.
    • Pests include: thrips, aphids, leaf-hopper, caterpillar, rose maggots, chafer, leaf miner, sawfly, leaf cutter, gall wasps, ants, mites and other maggots and bugs.
    • Diseases include: black spot, rust, mildew, leaf scorch, anthracnose, cancker & die back, botrytis (grey mould), gall, silver leaf, chlorosis, sooty mould and variations on the virus and fungus themes.

Another digitised version  .  The Enemies of the Rose by George Massee Frederick Vincent 1868- Theobald National Rose Society (Creator) Continue Reading →


Black Aphids on my Dahlias

These little breeders have been having a banquet on some of my Dahlias. They go for the soft new shoots and nascent flower stems which must be easy to get their teeth into. For some reason they have been quite selective on the plants they choose (As has been the spray I have used in a prophylactic manner). I hope the rest of the summer is black fly free but you never know.

Why are Black Fly Bad News

  • Black fly aphids or thrips are common sap-sucking insects. 
  • They are unsightly and look like they can do serious damage to plants.
  • As sap sucking insects they can create a lack of vigour and damage growth.
  • Insect secretions can go mouldy and add further problems to the dahlias
  • In severe cases viruses can be transferred to plants by these insects.

Lulled into a false sense of security by the low level of greenfly around my garden I wasn’t expecting black fly. I only left my dahlias alone for a few days and the flies multiplied like rabbits. I am on a more frequent look out patrol now. The muggy weather is one reason for the outbreak of black fly.


Winter Moth Problems on Fruit Trees

Fruit trees can be a winter home for a range of female moths. Amongst them are woolly aphis and capsid bugs plus other pests that emerge from the ground. They crawl up fruit tree stems and trunks in October to lay their eggs. The caterpillars hatch in spring and feed on the foliage and fruit.

Prevention and Treatment

  • To check the progress of these pests a barrier can be erected. Some fruit growers use a band of paper covered in tacky grease.
  • Tubes of special grease are now available specially for older fruit trees with rough bark where grease bands are less effective as pests can crawl under the band. Alternatively the bark can be smoothed first.
  • Winter moth and mottled umber moth need an  application at the beginning of winter before adult female moths climb trees to lay eggs. Apply again in summer to protect against ant infestations.
  • Rentokill call their product ‘Glue Bands’.
  • Grease any support stakes and low hanging branches.

Other Tips

  • Fix the grease band 1 ft below the lowest branch. Paint the stem with lime wash above the grease band.
  • Reapply after 2-3 months or renew the grease effect.
  • Also suitable for ornamental trees that are susceptible to infestation.
  • Keep bands free of dead leaves.



Why are Everyone’s Weeds Better than Mine

What is the collective noun for a group of dandelions?   A drift or adrift in my garden!

With so many potential ‘clocks’ ticking away to dispersal I wonder at the number of flowers on this fine weed. (Dandelion makes a wine but I am not so sure that it is quite so ‘fine’.)


Bindweed can be deceptively attractive except when flowering in my garden. I would call their group noun a ‘knot’ or a pestilence of convolvulous. Heaven forbid that they should become a congregation!


Soil and Healthy Grass

Grass Land, Meadows & Lawns

  • Getting to the grass root of the problem grass is the  largest irrigated crop in the USA.
  • Like other crops grass depends on the health of the soil in which it grows.
  • Moisture and nutrient retention is crucial to keeping your soil in good shape.
  • Clover is good news not bad news at least in moderation. I bit less attractive but a force for good with grass. Nodules on the clover store and deliver nitrogen more effectively than synthetic fertilisers.
  • Home chemical applications tend to be significantly over done compared to agriculture. Less not more is far better.
  • Water wisely in early morning. Evening watering can encourage some disease.
  • Allow clippings to fall back on the grass and rot down to keep the soil in good heart.
  • Higher cutting blades and grass helps prevent weeds and helps retain moisture.

Other Methods for Healthy Grass Lawns

  1. Scarifying – rake out the dead leaves and detritus
  2. Aerating  – spike the soil to allow air in and de-compact the ground
  3. Feeding – nitrogen rich food is the grass’s choice
  4. Top Dressing  – a bit of sand and soil brushed in helps new roots
  5. Moss Control – get rid of moss in spring
  6. Weed control – selective chemical weed killer
  7. Damage Repair – even the best lawns can get damaged – patches reseeding or just turning the edge of a turf around can help

Lily Beetle Spotting & Prevention

What has got 6 legs, a head, 2 eyes and red wings and  is not a dice game of Beetle. It is the red lily beetle Lilioceris lilii that consumes large quantities of one of our favorite plants.

How to Spot Lily Beetle

  • Adults are 8mm long, bright red with a black head and legs.
  • Eggs are 1mm long and orange-red, found in groups on the underside of lily leaves and they hatch in around a week.
  • Larvae have orange bodies with black heads but are normally covered with their own slimy black excrement.
  • The fully grown larvae are 8-10mm long.
  • At the pupal stage they lie in the soil.
  • Both the adults and larvae can defoliate lilies and fritillaries in short order.
  • Leaves get ragged and black gungy deposits can be seen on infected plants.
  • The red beetles easily fall off leaves and hide in the soil when gardeners try to remove them by hand.
  • The beetle was initially confined to south east England but has spread north.

The Lily Beetle Cycle

  • Adult lily beetles emerge from the soil from late March to May and feed on  foliage between May and  September.
  • Adults feed and lay eggs on the underside of leaves of host plants from late April until early September.
  • After about two weeks, when the larvae are fully grown, they pupate in the soil. Two to three weeks later new adults emerge.
  • The beetles overwinter as adults in sheltered places, often in the soil but not necessarily near lilies.
  • This non-native pest became established just before the second world war.

Prevention, Predators and Parasites

  • Red lily beetle overwinters in soil, leaf litter and other sheltered places so good husbandry can help.
  • Small infestations can be picked off by hand. There is some pleasure in squashing a red beetle that has caused your plant so much damage.
  • There are some parasitic wasps but probably not enough to help your lilies survive.
  • The RHS to which I am indebted for this advice say ‘ Pesticides are likely to be more effective on larvae than adults
  • Heavy infestations which are impractical to remove by hand can be treated with pesticides
  • Organic insecticides containing natural pyrethrins  Several application of these short persistence products may be necessary to give good control
  • Synthetic pyrethroid pesticides such as lambda-cyhalothrin (e.g. Westland Resolva Bug Killer), or deltamethrin (e.g. Sprayday Greenfly Killer) can be used
  • The systemic neonicotinoid insecticide acetamiprid (e.g. Bug Clear Ultra) can also be used’
  • In my experience it is wise not to expect miracles with chemical treatments and beware they can kill pollinating insects.

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