Job:06-700309 Title: CPS - Container Gardening Complete700309 - ContainerGardens_001-272_FINAL.indd 208 5/24/17 12:20 PM
Job:06-700309 Title: CPS - Container Gardening Complete
Job:06-700309 Title: CPS - Container Gardening Complete
700309 - ContainerGardens_001-272_FINAL.indd 209 5/24/17 12:20 PM208 chapter 4Black Spot (Diplocarpon rosae)
Description: Black spot is a fungal disease that
causes dark spots to appear on the leaves of rose
plants, and once it takes hold the leaves eventually
turn yellow and fall off. During particularly
bad years, the plant may become completely
defoliated. Black spot is a devastating disease for
rose growers across most of North America.Plants affected: Roses.Solution: Aside from planting resistant varieties,
be sure to remove infected leaves immediately
and toss them into the garbage or burn them.
Water roses only at ground level; avoid overhead
sprinklers. Black spot easily overwinters on fallen
foliage, so a good leaf clean-up in the autumn
helps. Organic fungicides based on potassium
bicarbonate or Bacillus subtilis serve to prevent and
manage black spot infections.Powdery Mildew (many species)
Description: Powdery mildew is the result of
several different species of fungal organisms that
live on the leaves of certain plants. It is largely
an aesthetic issue. Signs of a powdery mildew
infection are quite distinctive. White powdery
spots appear on the leaves and stems, most often
on the lower leaves first.Plants affected: Lilacs, phlox, bee balm,
cucumbers, grapes, squash, melons, and many
other common plants are susceptible.Solution: Aside from choosing resistant varieties,
keep the leaves as dry as possible. Since powdery
mildew is largely an aesthetic issue, there’s
no need to go to extreme measures to save
an infected plant. Organic fungicides, such as
those based on Bacillus subtilis and potassium
Black spot is a common fungal infection on roses. It bicarbonate, help keep powdery mildew in check.
causes dark spots on the leaves that eventually cause
the foliage to turn yellow and drop o.Powdery mildew makes plant leaves look as if they’ve
been dusted with baby powder. Though it’s largely an
aesthetic problem, a severe powdery mildew infection
can aect photosynthesis and plant growth.Text Black Job:06-700309 Title: CPS - Container Gardening Complete#175 Dtp: 229 Page: 208^700309 - ContainerGardens_001-272_FINAL.indd 208 5/24/17 1:07 PM
Troubleshooting 209Bacterial Wilt (Erwinia tracheiphila)
Description: Bacterial wilt begins as wilting
and drying of individual leaves. Because this
bacterium is spread by cucumber beetles, wilted
leaves may also show signs of cucumber beetle
feeding damage. More leaves shrivel as the stems
dry out. Soon, entire vines wilt, particularly during
the day. Eventually, the entire plant dies. For
confirmation, cut a wilted stem near its base and
touch your fingertip to the cut. Slowly pull your
finger away from the cut. If thin, white strands
of ooze thread from your finger to the plant,
bacterial wilt is probably to blame.Plants affected: All members of the cucurbit
family. Cucumbers and muskmelons are most
susceptible with pumpkins and winter and
summer squash showing occasional signs of
infection. Watermelons rarely fall victim.Solution: Plant only bacterial wilt-resistant
or tolerant varieties. Good cucumber choices
include, ‘County Fair’, ‘Salad Bush’, ‘Saladin’, and
‘Marketmore 76’. Butternut and acorn squash are
also resistant. The key to controlling bacterial wilt
is controlling the cucumber beetle. Cover young
plants with floating row cover and leave it in place
until the plants come into flower to allow access
to pollinators. Trap adult beetles by placing yellow
sticky cards just above the plant tops.Bacterial wilt is spread by cucumber beetles and
aects cucumbers and other members of the melon
and squash family. This plant has succumbed to
bacterial wilt.Job:06-700309 Title: CPS - Container Gardening Complete#175 Dtp: 229 Page: 208 (^) Text Black Job:06-700309 Title: CPS - Container Gardening Complete #175 Dtp: 229 Page: 209
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