Amateur Gardening – 10 August 2019

Regularfoodandwatercanstave

off blossom end rot

38 AMATEURGARDENING 10 AUGUST 2019

Q

Alotof mytomatoesareafflicted

byblossomendrot.How can I

preventit in futureyears?

Mr G Abram, Southport, Lancs

A

Blossomendrotis causedbya

lackof calcium.It is rareforsoil

andcomposttoactuallylackcalcium,

butforit toreachthefruitsthereneeds

tobea goodflowof watertotheplants.

Fruitsaredistantfromtherootsand

don’tcompeteaswellastheleavesfor

calcium,leadingtoa locallackof it at

theirends.If theyhavelimitedroot

space(inpotsorgrowbags)theyare

mostat riskof anirregularwatersupply.

A similarproblemcanariseif fertiliser

is addedtodrysoilaroundplants,

becausetheconcentratednutrientsin

thesoilwaterwill restrict water uptake

bytheplant.

High humidity can also limit water

Writetous:AskJohn,AmateurGardeningmagazine,

Pinehurst 2, Pinehurst Road,FarnboroughBusinessPark,

Farnborough,HantsGU147BF.

Email us:[email protected]

Q

Myrhubarbis riddledwithholes,

evennewshoots,andthere

appearstobea blister-likegrowththat

setsafterbeing sticky to begin with.

Whatis it?

Margaret Parkes, The Lizard, Cornwall

A

Itlooksasthoughyourrhubarb

leavesandstemshavebecome

infectedwitha fungaldisease called

Ascochytaleafspot.

Thefirstindicationof Ascochytaleaf

spotaremanysmallyellow-greenspots

thatdevelopontheleaves.Abouta

weeklatertheyturnbrownwithwhitish

centressurroundedbya redhalo.The

areaaroundeachspotturnsgrey/green

andbeginstodie.Thepictureof theleaf

is showingextremesymptomswiththe

wholeleafdead,butit clearlyshowsthe

remainsof thespotsthathavebeen

buildingupoversometime.

Sometimesthedeadtissueof the

spotsdropsoutof theleafandit may

beassumed,understandably,thatthe

holeshavebeencaused by some insect

eatingtheleaves.

However,it is nottimetothink this

is theendforyourrhubarb.

Hygieneis yourbestapproach,so

removeinfectedleavesduringthe

growingseasontohelptoreducethe

source of disease. Stems with infected

What isattacking

my rhubarb plant?

How can I beat blossom end rot?

It’s nota tomato!

Q

Thisplan

cameup

amongmy

tomato

seedlings

andI

decidedto

letit grow.It

nowhasfruits

onit, butI still

don’tknowwh

it is.Pleaseca

tellme?

Linda Browne, via email

A

Thisis blacknightshade(Solanum

nigrum), whichis in thesameplant

familyasthetomatoandpotatobutis

moreof a weedthana foodplant.

Thisis anannualplant,nativetothe

BritishIslesandcommonlyfoundon

arableandwasteland.It is poisonous

andtheberriesshouldnotbeeaten.

Butotherthanthat,it is nota worry

in thegardenandwon’t become a

significant nuisance.

Q

Pleasecouldyouidentifythisplant

formydad?

Helen Collins, via email

A

Thisis a colonyof appleof

Peru,alsocalledshoo-flyplant

(Nicandraphysalodes). A nativeof Peru,

itsviolet-blue,white-centredbell-shaped

flowersarefollowedby green lantern-

likeseedvessels.

Itis visuallyappealinganda single

plantreleasesthousandsof seedsthat,

thefollowingyear,producea hostof

seedlings,whichrapidlydevelopinto

plants 4-5ft (1.2-1.3m) high and across.

Mystery arrival

Leafspotis a commonfungal

problem aff ecting rhubarb

leavesshouldbeharvestedfirst as the

stemsarestillsafetoeat.

Attheendof thegrowingseason,

aftertheleaveshavedieddown,remove

anddisposeof allremainingplant

material,burningthemortaking them

toa householdwastesite.

Leafspotis moreprevalenton

rhubarbplantsthatarestressedin some

way.It is encouragedbypoorfertilityand

it is mostbeneficialtofeedplantswitha

highnitrogenfertiliserassoonasgrowth

resumesin thespring,withanotherlight

nitrogenapplicationaboutlateJune

whentheharvestis complete.Other

stressfactorscouldbepoorlydrained

soil,droughtandovercrowded plants

in need of division.

uptake,sogooddaytimeventilation

is helpful.Affectedfruitswon’trecover,

butyoucanpreventtheproblemby

stoppingthecompostfromdryingout.

Youmayneedtowatertwicea dayin

verydryweather,morningandevening.

Feed weekly with tomato feed.

Theshoo-fly plantis attractive but

can be invasive

Blacknightshadeis

a memberofthe

tomato family