Download PESTS AND DISEASES

PESTS AND DISEASES
THRIP: These tiny insects are only 1/25 of an inch long yet if left to infest they can
cause a great amount of damage to your roses. Thrip have piercing mouthparts, which
they use to obtain sap and water from the roses usually while still in bud form. Thrips
are mobile and will crawl, jump, walk or fly to any target they focus on. Having
Thrips feeding on your roses will result in dull blooms, sometimes completely
deformed and usually with a bruised look around the edge of the petals. To eradicate
Thrips in your garden, trim all infected flowers off the bush and spray with an
insecticide such Malathion or Confidor.
APHIDS: Aphids are small, soft bodied sucking insects that feed in colonies on your
roses young leaves and succulent new shoots, making them especially prevalent in
Spring and Autumn. Aphids can be green, black or brown and when feeding on your
roses often cause the foliage to curl and become deformed as they have literally
sucked the life from your new growth. Aphids excrete a sugary waste product called
honeydew, which appears like a ‘snail trail’ and does attract ants, bees and wasps.
Aphids can be eradicated by the use of an insecticide such as Malathion or
alternatively the Beat-a-Bug Insect spray is completely natural made from Garlic and
Chilli and works a treat! New to the market is a granulated insecticide called Resolva
which is very effective in preventing Aphids and Thrip infecting your roses if put
down on the soil after pruning.
SPIDER MITE: Spider Mites are microscopic and cause damage by removing sap
from the undersides of the leaves causing them to develop a bronze colouring. The
undersides of the leaves may have a silken webbing adhered to them and the eggs
appear as tiny grains of sand stuck to the leaf. As a result of the mites the pigment is
drained from the foliage and often the plant will defoliate. Breeding in warm, dry
places, Spider Mite is highly prevalent in late spring and summer. We recommend a
miticide named KELTHANE to eradicate Spider Mite, which should be applied over
the entire plant especially under the foliage. Another product that can be used and is
also organic is NEEM OIL – very effective, readily available and safe!
LEAF CUTTER BEE: If you have something eating your roses by taking a perfect
semi-circle from your foliage it is more than likely the Leaf Cutter Bee using your
roses to build a nest. Once they have completed their nest they usually leave your
roses alone and we do not recommend spraying, as it will kill the “good” bees as well.
Their nest is usually found in a tree nearby or under the capping of your fence.
BLACK SPOT: Black Spot is caused by the fungus Diplocarpon rosae and tolerates
a wide range of temperatures. It does need a high relative humidity and infection is
greater on leaves that remain wet for six or more hours. Lower leaves are usually the
first to become infected by developing the black spot, turning yellow and ultimately
dropping off. Infected fallen leaves blown by the wind will disperse the fungus around
your garden so raking them up will help. We recommend spraying with TRIFORINE
or MANCOZEB regularly to keep black spot under control.
POWDERY MILDEW: Powdery Mildew appears as a white/grey powdery fungus
growth over the foliage, stems or flowers of the infected rose. Young foliage and
stems are most susceptible. Mildew usually prevails on roses that are retaining too
much moisture and/or not getting enough sunlight. Leaves can also curl and become
burnt on the edges when the sun becomes more intense. To eradicate powdery mildew
we recommend spraying with TRIFORINE twice in 2 weeks.
RUST: yellow rust spots appear on the topsides of leaves in the cooler weather of
Autumn and Spring. These infected leaves become twisted and dry and usually drop
off. To control rust we recommend spraying with a fungicide such as TRIFORINE
twice over a fortnight. Thinning the bush out before spraying will also help eradicate
the infection.
IRON DEFICIENCY: A deficiency in iron will cause yellowing of the younger
leaves and leaf veins will remain a darker green in contrast to the rest of the leaf. Iron
is essential for the growth of your roses as well as disease resistance. The most
common cause of Iron deficiency is a high PH (Over 6). This problem is especially
prevalent in coastal or limey areas and can be corrected by the application of a soluble
substance named Chelated Iron – this is also available in a liquid form (Irondex). If
you live in an area with high limestone content we recommend using cow manure in
September and January as well as a regular feeding of Black Magic Rose Food.
DIEBACK: If your rose stems are starting to go black at the ends and this is
travelling down your stems you could have dieback. If you suspect this is happening
to your roses it is important to spray with a product called Rid-a-rot twice in 3 weeks
before you cut any dead pieces off the ends. Mixing seasol in with the rid-a-rot at time
of spraying will improve the bushes no end. After two applications of the spray you
can then safely cut off any dead ends.
When spraying weed killer in your garden be extremely careful around your roses. If
your roses come in contact with weed killer, even the slightest drift is all they need,
their growth will become stunted and feathery looking, which takes them on average
of about two seasons to grow out of. In extreme cases the roses will never recover!
NOT SURE? CUT A PIECE OFF THAT IS INFECTED AND WE
CAN ADVISE YOU IN PERSON.