South African Garden and Home – September 2019

84 SEPTEMBER 2019 | gardenandhome.co.za

SOURCEBallStraathof

ballstraathof.co.zaor 0117942316

DOWNYMILDEW

Whatisdownymildew?

ThisiscausedbyanImpatienshost-

specificwatermould,Plasmopara

obducens.Itdevelopsrapidlyinmoist

rainyweatherwherethereishigh

humidityandnighttemperaturesare

cool.Asaresult,leavestendtostay

moistforlonger,whichencourages

thegrowthofspores.Downymildew

hadsuchadevastatingimpact

becauseitiseasilyspreadbywindas

wellassplashingwater.Sporesare

alsoabletooverwinterintheground

andreinfectimpatienswhenthe

weatherwarmsup.

Whatdoeshighlyresistantmean?

Thetermisusedforplantsthatmay

showsymptomsofdisease,especially

whenunderpressurefromadverse

weatherconditions,butcontinue

toliveandthrive.Leavesmaybe

droppedordiscoloured,butplants

don’tdie.Downymildewisathreat

tovarietiesthataren’tresistant.

OTHER IMPATIENS
When downy mildew struck eight
years ago, the alternatives were the
larger New Guinea varieties that
were immune to the disease. They
also formed the basis for interspecific
breeding programmes that resulted
in hybrids that could be used in beds,
containers and hanging baskets. Each
has their own specific characteristics.
SUNPATIENS
One of the first interspecifics, it’s
known as the ‘all weather impatiens’ as
it puts on a display in summer through
to the first frosts. Plants are robust

enough to grow in full sunorpartial

shade. This compact seriesgrowsup

to 35cm high and wide, makingita

good alternative for beds thatreceivea

bit more sun as well as containers.The

larger series grows up to 70cmhigh,is

suitable for landscapes, towardstheback

of a border, large containers.Plantthem

in full sun and water dailyinsummer.

They are forgiving plants –thebeauty

of all impatiens. If they flopfromalack

of water, they’ll bounce rightback

after watering.

CLOCKWORK

An upgrade of the CelebretteNew

Guinea pot impatiens (I. hawkeri),

Clockwork has the ideal compact

growth (25cm high and 30cmwide)

for patio containers and plantersand

performs equally well in beds.Itcomes

in a wide colour range, includingtwo-

tone ‘Pink Star’ and ‘OrangeStripe’.

Plant them in a good qualitypotting

mix, with a controlled-releasefertiliser.

The best position has morningsunand

afternoon shade or good, dappledlight.

Water pots once a day in midsummer

and feed with a liquid fertiliseronce

a month.

DIVINE

This New Guinea landscapevariety

has the largest colour range of all and

includes soft colours such as lavender,

pearl, soft pink as well as some brighter

Clockwork ‘Appleblossom’

NewGuineaDivine’Lavender’

Sunpatiens

shades. It’s compact and quick-growing

and supplied in seedling trays in single

colours or mixes. These make a show,

especially in a large bed, as an edging

and in hanging baskets.