Chemical Aids to Gardening

Four chemicals play a significant role in the care and enjoyment of the home grounds today:

Chemicals For GardeningPin
  • Granular cyanamid
  • All-purpose sprays (for fruit and ornamentals)
  • Brush killers
  • Sequestrene

Granular Cyanamid

Granular cyanamid was used to make weed-free lawns and the renovation of old turf.

As a nitrogen-lime fertilizer, it accomplishes this double-action role by being able to kill sprouting weed seeds before their fertilizing ingredients are made available to the grasses.

After cyanamid is incorporated into the soil to the recommended depth of 4″ inches, 3 weeks must pass before the lawn is seeded to allow the material to complete its conversion to useful soil elements.

Calcium cyanamid (another name for this chemical) works best in seedbed preparation when there is moderate moisture in the soil.

However, overwatering or excessive rainfall reduces its effectiveness.

Soil temperature affects the use of cyanamid in seedbed preparation. Therefore, the best results are obtained when the soil temperature is around 70° degrees Fahrenheit.

Cyanamid is recommended for lawns that are built in the early fall. This is because crab-grass seeds do not sprout until early summer, and a spring application could not, therefore, control them.

Besides crab-grass, the common weeds that can be controlled by cyanamid are the following:

  • Purslane
  • Chickweed
  • Corn-grass
  • Dandelion
  • Plantain
  • Sour-grass
  • Lamb’s quarters 
  • Dock

All-Purpose Fruit Sprays

All-purpose fruit sprays contain the following:

  • Sulphur
  • Copper
  • Horticultural Oil

They are effective in the control of the following:

  • Codling moth
  • Curculio
  • Leafhopper
  • Oriental fruit moth
  • Apple maggot
  • Tent caterpillar
  • Japanese beetle
  • Rose chafer (on apples, pears, peaches, and prunes)

They also protect against fungus diseases, such as:

  • Apple and pear scab
  • Brown rot and scab on peaches
  • Brown rot on plums and prunes

All-purpose sprays for ornamentals contain:

  • Lindane
  • Malathion

These foliage sprays control:

  • Red spider
  • Thrips
  • Japanese beetle
  • Psyllids
  • Chrysanthemum fly
  • Leafhopper
  • Woolly aphid
  • Mealy bug
  • Scale
  • Leaf-roller caterpillar
  • Armyworm
  • Leaf-miner
  • White fly
  • Diabrotica beetle
  • Grasshopper
  • Sowbug

All-purpose sprays are recommended for roses, camellias, gardenias, and most other woody plants.

The homeowner can apply these sprays with a knapsack sprayer, using a stepladder to reach the tops of dwarf fruit trees and the taller shrubs.

It is recommended that he don a rubber raincoat and protective gloves for this task.

Brush Killer Chemicals

Brush killer chemicals (2, 4, 5-T) can be applied in a knapsack sprayer on growth up to 6’ or 8’ feet in height after the foliage is well developed in the summer.

At that time, the chemicals may be mixed with water. Larger trees may be destroyed by painting the bark to 18” to 24” inches.

The homeowner will find brush killers to be most useful in selective woodlot clearing and improving any wooded area surrounding his lawn and garden area.

Two important points about these materials are that women can use them with no difficulty and that desirable plants can be saved while unwanted ones are permanently destroyed.

It should be pointed out that brush killers work slowly. The period for permanent control will vary from 3 to 6 months or even a year for large trees.

When the plants actually die, it is time to cut and remove them as never before.


Sequestrene, Nafe, corrects iron deficiency with the result that impoverished, dying plants are restored to new life and vigor by applications at intervals.

Better color results, also more buds and flowers.

Most importantly, many plants not apparently deficient in iron are spurred to greater activity and sprout new growth after treatment.

Ornamentals that respond particularly well to Sequestrene include:

  • Azaleas
  • Camellias
  • Laurels
  • Chrysanthemums
  • Gladiolus
  • Hollies
  • Hydrangea
  • Privets
  • Andromedas
  • Rhododendrons
  • Roses
  • Snapdragons

Magnolias, pin oaks, Russian olives, sand cherries, spruces, and boxwood also respond to this chemical which can be applied from a knapsack sprayer.

Repeat Spraying If Needed

It is important to remember that a repeat spraying with a sequestrene solution may be necessary, so a supply should always be on hand.

If a drenching rain should wash off the material after it is applied, the only recourse is to spray again as soon as possible.

Note that extremes in temperature following a spray application can also reduce its effectiveness.

The agricultural chemicals mentioned in this article for information about them) are available from local horticultural or florist supply houses.