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In wet years it blights dogwood, infected anthers and bracts rotting onto young leaves. It affects
leaves, flowers, and corms of gladiolus grown in Florida and humid sections of the Northwest. The gray mold kills stems of eupatorium, causes
a basal rot of pansies (especially if they are held too long in the box
before being planted in your garden); it rots lettuce and lima beans. If
raspberries and strawberries are picked in damp weather, half the box
may be covered with mold by the time it gets to your kitchen.
Control. Cut fading flowers into a paper bag as you walk around the
garden; dig up and destroy blighted pansies and lettuce; ignore the dogwood blight; spray gladiolus with Dithane Z-78 or Parzate; keep green-
house plants widely spaced with good ventilation and avoid overhead
watering.
LILY BOTRYTIS BLIGHT (Botrytis elliptica),
general on lilies but most serious on Madonna lilies. If blight strikes early the entire growth can
be killed, but more often the disease starts with oval, reddish or orange
brown leaf spots (Figure 13C) which later grow together to infect the
whole leaf. In cool, moist weather blight starts on the lowest leaves and
works progressively up the stem, until most of the foliage is blackened
and hanging limp. Buds rot or open to distorted flowers with irregular
brown specks. The fungus winters either in very small black sclerotia
formed on fallen petals, dead stems, or leaves or as mycelium in the basal
rosettes of Madonna lilies.
Control. Avoid too dense planting; avoid shady and low spots with
little air circulation; cut out blighted stalks before sclerotia can be formed.
Spray with bordeaux mixture or a fixed copper at 10- to 14-day intervals
from the time lilies are a foot high to flowering.
PEONY BOTRYTIS BLIGHT (Botrytis paeoniae),
present wherever peonies are
grown. In a rainy spring young shoots rot off at the base as they
come through the ground or shortly thereafter, especially if they have to
emerge through a leaf mulch or manure. Small buds turn black and
never develop, half-open buds blast, or full-blown flowers turn brown,
with a short, thick, velvety gray mold covering affected parts in moist
weather. Leaves have brown spots when fading flowers rot onto them.
Small, flat, black sclerotia are formed closely appressed to the stalks, usually near the base.
Control. Cut all stalks in October at ground level; do not leave even
an inch of stubble. You can mark the spot, so you don't disturb peonies
in bulb planting or other operations, by three sticks at the circumference
of each planting. Burn all tops; never use them for a winter mulch;
avoid mulches, except possibly salt hay the first season after planting.
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Types of Garden Enemies
