Garden chemicals are available in greater numbers this year than ever before.
Years ago insecticides and plant growth regulators were introduced for home use.
Most of the “old reliables” are not around to help make gardening more enjoyable and more successful.
Malathon is perhaps the most crucial “old timer” for insect and mite control.
This organic phosphate combines high insect- and mite-killing power with a low order of toxicity to man, pets, and plants.
Malathon, which the American Cyanamid Company developed, helped home gardeners solve many insect problems on fruit trees, vegetables and flowers as effectively as parathion does for commercial growers.
It appears especially effective against the “hard-to-kill” insects. One research worker found, for example, that a single spray containing one ounce of 50% percent Malathon emulsion in 3 gallons of water gave 100% percent control of early and adult stages of mealybug.
The Euonymus scale was controlled with 4 ounces of emulsion in three gallons of water.
Malathon will be specially formulated and packaged by many well-known manufacturers and should be available when this article is printed.
Where mites alone are a problem, gardeners used one of several excellent miticides.
Mite-killers with long-lasting residual effects include:
- Insecticidal soap
Malathon, mentioned above, is also effective against mites.
DDT Sprays And Dusts
DDT sprays and dusts were used until 1972 to the control certain insects, especially borers in the following plants:
- Mountain ash
Two applications at two-week intervals of a spray containing one pound of 50% percent wettable DDT in 25 gallons of water gave good control of these pests.
The time to apply the first spray varied with the locality.
Gardeners should remember that frequent and heavy doses of DDT may injure some plants and may increase the mite population in others.
If the latter situation arises, one of the mentioned miticides can be used. Some gardeners include a miticide in the DDT spray as a precautionary measure.
Lindane was another of the “newer” insecticides used in greater amounts because it controlled several highly destructive insects.
One ounce of 25% percent wettable lindane powder in 6 gallons of water sprayed on the leaves of birches gave good control of the birch leaf miner.
The spray was applied when the leaves were well expanded—by May 15 in the northeastern United States.
A second spray should be applied 6 weeks after the first to control the second generation of this pest.
Lacebugs on andromeda, azalea, hawthorn, oak, sycamore, and rhododendron were controlled with two applications of the same spray.
State and federal entomologists supplied the recommended starting dates for spraying particular plants on request.
Chlordane was a good control of certain other pests.
One ounce of actual chlordane distributed over 1.000 square feet controlled chinch bugs and cutworms.
Four ounces of actual chlordane for every 1,400 square feet controlled the grubs of the following pests:
- Japanese beetle
- Oriental beetle
- Asiatic beetle
- May beetle
- Rose chafer
DDT was also used to check Japanese and oriental beetle grubs.
Much was written about so-called systemic insecticides.
These are chemicals absorbed by plants from solutions applied either to the soil or to the leaves so that the plant sap becomes toxic to certain sucking and chewing insects.
Such materials are obviously applied to ornamental plants only. Decades ago, the best-known chemicals used as systemic insecticides were:
- Sodium selenate
Selenate compounds are available under the trade names:
- Sel Kaps
Two other systemic insecticides—Pestox 3 and Systox—reached commercial development.
House Insecticide Bombs
Apartment house dwellers and other house plant enthusiasts were interested in an insecticide bomb for use on house plants.
It was called D-X Aero-Spray and made by the B. G. Pratt Company of Hackensack, New Jersey.
The old-fashioned hand sprayer was no longer needed since this spray came in a can under pressure.
One needs to push down a button to release the insecticide containing pyrethrum, rotenone, and piperonyl cyclonene.
It was recommended for use on such plants as:
- African violet
- Boston fern
- English ivy
- Kentia palm
- Rubber plant
Aphids, spider mites, thrips, and white flies were some of the pests it checks.
The Antrol Push-Button Rose Spray flower bomb, manufactured by Boyle-Midway, Inc. of New York, released a combination of insecticides to control aphids, Japanese beetles, leafhoppers, and thrips on roses.
Old Reliable Products
Despite the introduction of “new insecticides”, many old-time products continued to do a good job of controlling pests.
Rotenone sprays and dust were popular, time-tested, and considered non-poisonous (to humans and pets).
They find their greatest use in edible crops like beans, lettuce, and spinach.
Although poisonous to humans and pets, arsenate of lead and nicotine sulfate was used for the non-edibles, such as trees and shrubs.
Gardeners who wonder why so-called “wonder drugs” are not used to control plant diseases will be interested to learn that the Upjohn Company marketed an antibiotic that did just that.
Known as Acti-dione, it controlled certain diseases of golf putting greens, including the one called “melting out,” for which no other control measure was known.
Here then, a company manufactures drugs for the health of man and animals and makes an antibiotic for combating plant diseases!
Other available fungicides included Ferbam for the control of the following:
- Cherry and peach brown rot
- Tomato leaf spot
- Apple scab
- Rose blackspot
- Cedar rust
The use of Ziram is controlled for the following diseases:
- Early tomato and potato blights
- Celery blights
- Bean anthracnose and carrot
- Beet and pepper leaf spots
Nabarn fungicide for cucumber, cantaloupe, and onion mildew -diseases.
Also available were the “old reliables” of the plant doctor’s kit, the copper and sulfur compounds, sold under many different trade names.
Many manufacturers prepared combination sprays for fruit trees that contain both insecticides and fungicides. These merely required dilution in water before application.
Most gardeners know about the selective weed killers containing 2,4-D, which are highly effective in ridding lawns of dandelions and plantain.
One of the principal drawbacks of weed killers of this type is their high volatility. In addition, fumes from 2,4-D spray often damage trees, shrubs, and vegetables growing near the lawns being treated.
To overcome this serious drawback, many of the new weed killers containing 2,4-D and 2,4,5-T are formulated with butoxy ethanol esters that do not volatilize and hence are not apt to damage nearby plants.
For crabgrass control, the two best chemicals developed were:
- Potassium cyanate
- Phenyl mercury acetate
They were sold under a dozen different trade names. Directions must be followed to the letter to control crabgrass yet avoid injury to desirable grasses and harm to humans and pets.
The new pre-emergence type of herbicide greatly facilitated the weeding of certain crops.
Strawberries and asparagus, and other perennials were kept weed free by spraying Crag Herbicide 1 on the soil after cultivation.
Crag had almost no effect on mature foliage of either weeds or garden plants.
It worked in the soil by killing seedlings less than 1-inch high. Some of the older chemicals were also used in this manner.
Alanap was a new pre-emergence herbicide.
Poison Ivy Control
Ammate continued to be one of the most popular poison ivy destroyers.
When used to kill poison ivy growing on a desirable tree, the spray should be applied to the ivy leaves only and not allowed to touch the tree’s foliage.
Nor should too much Ammate be allowed to soak into the bark or soil.
Ammate was not highly selective. It killed other vegetation in close contact with poison ivy.
Mixtures of 2,4.-D and 2,4,5-T also destroyed poison ivy and other vegetation. These were known as “brush-killers” or “woody-plant killers.”
Where eradication of all vegetation was desired, the powerful, non-selective weed killer known as CMU was recommended.
CMU came as a powder to mix with water. One spraying when weeds and grass are just starting to grow in spring will give control for an entire season or longer.
It was nonflammable, nonvolatile, and noncorrosive to equipment.
Selective Clover Killer
Most gardeners like to have some clover on their lawns. On golf putting greens, however, clover is highly undesirable.
For such situations, scientists have developed the chemical Endothol, which had a special affinity for legumes. As a result, it destroyed clover without harming grasses.
This product was sold under the trade names:
Fusarex was a new potato sprout inhibitor containing 3% percent tetrachloronitrobenzene.
It prevented excessive sprouting for 3 to 6 months when applied at storage time at the rate of 3 ounces to a bushel of potatoes.
Other sprout inhibitors containing naphthaleneacetic acid also retarded the sprouting of potatoes.
These were commercially available as:
- Sprout Lok
- Potato Fix
Another chemical welcomed by homeowners, especially those with large lawns, was the growth regulator maleic hydroxide, developed by the United States Rubber Company.
The early formulation of this product, a liquid known as MH30, was found capable of checking or slowing the growth of certain shrubs and grasses.
However, it had several drawbacks and was never put on the open market.
The company made available an improved formulation, MH40, a dry water-soluble powder containing 40% percent active maleic hydrazide.
It was marketed under such trade names as KemKut, Stop-Grass, and the like.
When sprayed on lawns as directed, it slowed down the growth rate of the grass. As a result, treated lawns needed mowing less frequently.
Seedless Tomato Hormones
Firmer, meatier tomatoes can be produced well ahead of the regular fruiting date by using “blossom-set” chemicals that take the place of natural fruit-setting hormones.
The chemicals make the blossoms set fruit despite low night temperatures and lack of pollination and fertilization.
Among the trade names for these chemicals are:
- Tomato Set
Certain synthetic hormones are a great aid to plant propagation because they hasten and increase the formation of roots on cuttings.
These rooting preparations are of two kinds:
- Indolebutyric acid (Hormodin)
- Naphthaleneacetic acid and its related compounds (Rootone)
Both types are available in different strengths because some cuttings require greater stimulus than others.
Snail And Slug Controls
Partially shaded flower and vegetable gardens are ideal spots for developing snails and slugs.
There is nothing better than specially prepared baits containing the chemical metaldehyde as the attractant and the poisoning agent to control these pests.
These baits are sold in most seed stores under a half dozen different trade names.
Damage by rabbits and deer were reduced by spraying with the material known as Goodrite z.i.p.
One application of z.i.p. during the growing season broke animals from feeding in that particular area.
Subsequent applications to protect new growth were usually effective in reduced concentration. This repellent was not applied to plants about to be harvested, nor to edible plants such as lettuce or other greens.
It could be used on carrots, peas, and up to the blossom stage of snap beans.
Goodrite z.i.p. was compatible with many insecticides, including:
- Nicotine sulfate
Death of newly moved trees and shrubs due to excessive water loss can be virtually eliminated by spraying them before digging with the material known as WiltPruf.
Conifers, broad-leaved evergreens, deciduous trees, and shrubs in the leaf are more safely transplanted.
They survived drought and transplanting shock better when sprayed with Wilt-Pruf as directed by the manufacturer, Nursery Specialty Products of Eastview, New York.
Confusion was reduced after the flood of new soil conditioners subsided.
Some brands widely advertised disappeared from the shelves.
Select a soil conditioner put up by a company of unquestionable reputation. Such firms have usually been in business a long time and cannot afford to market an inferior product.
Gardeners should never forget that not all the know-how of the world’s greatest chemists is ever likely to devise a packaged substitute for sound gardening fundamentals and good old common sense.