36 AMATEUR GARDENING11 MAY 2019
Ask John Negus
Johnhasbeenanswering
reader queries for 49 years
Q
Thebloomsonmybeautifulwhite
camelliashrubturnedbrownafter
justthreeweeksof flowering.Whatcan
I dotopreventthisin thefuture?
Stan Addison, via email
Why has my camellia browned?
Seedlingfailures
Q
Someof myseedlingshave
suddenlykeeledover and died.
Whatis theproblem?
Andrew Barton, Scarborough, Yorks
A
Itsoundslike‘dampingoff’,a
rapidlyspreadingfungalinfection.
Overlywetcompostandwarmhumid
conditionsencouragethegrowthof
ungi,suchasthoseresponsiblefor
dampingoff’andalsoforrottingseeds.
Toavoidit, alwaysusefreshseed
compostandcleantapwater,keep
compostdampbutnotsoggy,andmake
urethereis good airflow around
he seedlings.
Q
Pleasecouldyouidentifythis
gorgeousplant?
Mrs Joyce Hall, Potters Bar, Herts
A
ThisisAlliumsenescensfrom
EuropeandnorthernAsia.Try
interplantingit withwhite-flowered
Veronicagentianoides. Floweringfor
muchof latespringandearlysummer,its
pinkumbelsarea joy.It is similartothe
uncommonBritishwildflower rosy garlic
(Allium paniculatum).
Mystery plant
Pale-floweredcamellias
canbelesshardythan
darkervarietiesandare
morevulnerableto
frost damage
A
Sadly,whitevarietiesofCamellia
japonicaarelesshardythan
pinkandred-floweredformsandare,
therefore,vulnerabletofrostdamage.
Infuture,whentheskyclearsat dusk
anda chillynightis forecast,drapeyour
bushwithtwoorthreelayersof fleeceto
protectflowerbudsandblooms from
cold-weather damage.
Removefleecethefollowing morning
whenthetemperaturerises.
Additionally,strengthenyourcamellia
byfeedingit withsulphateof potash.
Sprinkle1oz(28g)perm^2 overtheroot
areaandwaterit in.Applyit monthly
fromApriltoSeptember.
If youlivein anareawithhardwater,
yourtapwatermaycontaintoomuch
calciumandthiswillreducetheacidity
of camellias’preferredsoil and compost
overa periodof time.
Userainwaterinstead,thoughtap
wateris finetousejustfor a month or
two over the summer.
Q
Whatis thebestwaytosharpengardentools?
Elwin and Helen Humphrey, Teignmouth, Devon
A
Let’sstartwithsecateurs.Therearetwotypes:anvil,in whichtheblade
closesupona flatanvil,andcurved,alsoknownassideanvilorbypass,
whenthesharpenedbladebypassesa broadbladethatis notsharpened.
Ideally,usea fine-gradewhetstonetosharpenthecuttingbladeand
followtheangle,whichis about75°,thatwasfashionedwhen the secateurs
weremade.Asforshears,usea whetstonetosmoothth
flatareaof bothbladestocreatea sharpedgeone
TheRHSandBBCGardeningwebsites(rhs.
org.ukandbbc.co.uk/gardening)bothhave
sharpeningadvice,andlargergardencentresthat
stockbooksmayalsocarrygardeningguides.
Youcanalsobuya Multisharp 1501 4-in-1
sharpenerforaround£10,which is available
from DIY stores and online.
How should I sharpen my tools?
Dampingoffdiseasecanaffect
seeds and new seedlings
Alamy
Sharptoolscutcleanly
and are safer to use
Alliumsenescenshails from Europe
and northern Asia