Leafhopper |
|
Spray the plants in early
May and repeat three times at three-day intervals. The second
solution is effective against grubs and black spot on roses. Both
solutions can be frozen. Diatomaceous earth, pyrethrum and rotenone
can be used to kill leafhoppers, scarab
beetles and mealybugs, but they are not selective pest controls, so
they should be used only as a last resort.
Remove and burn all leaves with insects or eggs on them. Flying
insects do not like humidity. Spraying plants in sunny weather, or
sprinkling a little lime on the leaves in the early morning will
keep these pests away. A mulch of oak leaves will repel insects
that chew foliage.
| Diseases that affect roses
|
As a preventive measure, always use disease-free flowers, bulbs
and seeds. Generally, plants sold at garden centres are
disease-free. To reduce the risk of disease, you should rotate
annuals. You can steep some fresh chives for 15 minutes and then
spray this solution on plants to prevent fungus infections such as
mildew. Mildew may develop in cool weather, forming grey powdery
spots on leaves shaded by trees. A spray of milk or diluted human
urine is also effective against mildew.
To keep insect pests away, plant some aromatic herbs in June,
and some nicotiana in your flower beds with your perennials and
other flowers. At the base of your rosebushes, plant any of the
following: garlic, chives, mint (mint spreads quickly, so plant it
in a pot), anise, coriander, parsley, lavender, geraniums,
petunias, nasturtiums, lupines or marigolds. These plants are good
companions that guard against disease and pests. Tomato plants
grown in a sunny, well-aerated flower bed will repel insects.
Umbellifers such as parsley and sunflowers attract beneficial
predators in early spring. Aphids are repelled by chives, garlic,
mint, wormwood, anise, coriander, petunias and nasturtiums.
A lack of fertilizer, poor drainage, too much manure or peat,
and poor air circulation are factors that inhibit the growth of
flowers. You can fertilize your garden by working peat moss, bone
meal and blood meal into the soil. Too much nitrogen increases the
risk of aphid infestations and diseases such as rust and mildew.
Perennials must be fertilized twice a year, in spring and mid-July.
In fall, dig some bone meal into the ground around the bulbs, stop
fertilizing with nitrogen, and remove plant debris from your flower
beds and soil.
In spring, remove the winter protection from your rosebushes,
perennials and flower beds. Prune any weak, diseased and damaged
stems from bulb plants and perennials, and turn the soil over with
a spading fork. Water the plants during hot spells. Remove dead
flowers from annuals and perennials throughout the summer. You can
plant in spring or fall. Do not plant rosebushes near trees that
may hoard nutrients and block sunlight.
Rosebushes are more susceptible to disease than other flowering
plants. They require from six to eight hours of sunlight a day. The
soil must be loose, well drained and slightly acid. It is important
to provide adequate air circulation between rosebushes; roses
planted too close to the house are more susceptible to mildew
because of poor air circulation. Roses need plenty of water during
hot spells. Water thoroughly in the morning once week. Watering
roses too often and late in the day promotes disease. You can use a
mulch of wet peat moss to keep the soil cool during hot weather.
Remove the mulch before winter if it has not decomposed. Mulch also
reduces water splashes, which tend to favour the spread of fungi,
such as black spot. It is a good idea to remove dead and diseased
leaves throughout the summer.
In the fall, removing dead and diseased leaves reduces the risk
of disease. Watch for signs of mildew: the cool, damp evening air
favours the development of mildew. Mound up the soil around the
rosebushes and cut back long branches. After the first frost and
after making sure that there are no rodents, add some straw or
leaves from healthy trees, or place a
cone on the mounds. This mulch protects
the plants from the cold.
Cone
In the spring, remove the mulch and mounds of earth before the
buds appear. Cut off dead branches and leaves that show black spots
or other signs of disease. Fertilize in spring and summer with a
mixture of fish emulsion, dried blood and bone meal. Stop feeding
in early August.
| Natural controls give better results |
There are many publications that you can consult for guidance on
caring for annuals, perennials and roses. With a minimum of
monitoring and attention, you will be able to keep your plants
healthy and protect them from disease. Natural controls are
easy-to-use, ecological solutions that will help you grow healthy,
beautiful roses and other flowers.
Foster, Catherine Osgoode. 1975. Organic Flower Gardening.
Emmaus, PA: Rodale Press. 305 p.
Kourik, Robert. 1986. Designing and Maintaining your Edible
Landscape Naturally. Santa Rosa, CA: Metamorphic Press. 370 p.
Riker, Tom. 1978. The Healthy Garden Book: How to Control Plant
Diseases, Insects and Injuries. New York: Stein and Day. 224 p.
Smith, Miranda and Anna Carr. 1988. Rodale's Garden Insect,
Disease and Weed Identification Guide. Emmaus, PA: Rodale Press.
328 p.
Collaborators : Sylvie Deslauriers, agronomist.
Département de santé communautaire de
Lanaudière
Fore more informations contact :
Environment Canada
Inquiry Centre
105 McGill Street, 2nd Floor
Montréal QC
H2Y 2E7
(514) 496-6851
1-800-463-4311
Published by Authority of the Minister of the Environment
© Minister of Supply and Services Canada 1991
Cat. No. EN 40-206/8-1991E
ISBN 0-662-18786-5
|
