Gardeners have been using herbal insecticides as a safe alternative to chemical based insecticides for thousands of years. Though many herbs, including rosemary, ginger and bay leaf, can kill and deter insects in your garden, they are generally safer for small children and pets than commercial, chemical-based insecticides. Preserving the herb in a plant-based oil both maintains the beneficial properties of the herb and creates a compound that can be sprayed, spread or mixed easily.
Place 4 ounces of fresh rosemary at the bottom of the clear glass jar. Pour in enough safflower oil to cover the herbs. Close the jar with the cover and place in a warm, sunny spot for at least two days.
Open the jar and pour oil through the strainer into the measuring cup. Discard the remaining herbs.
Pour 2 ounces of the strained oil into the spray bottle. Add 2 ounces of liquid soap and 8 ounces of water.
Shake bottle until mixture is blended. Shake the bottle before every use, because the components will separate.
Spray evenly over the plants to be treated. Hold the bottle at least 12 inches away from the plants when you spray.
Plant the rosemary in the pot. Insert the bamboo stake alongside the rosemary. Secure the rosemary to the stake with the twist tie.
Strip the bottom 2 inches of leaves from the rosemary. Continue to strip new growth periodically as the plant grows, always leaving only the 2 inches of growth in place. The stem of the plant will thicken and grow woody over time. Attach new twist ties as needed to hold it to the stake. Water regularly and feed with a slow-release fertilizer.
When the plant is approximately 1 foot tall, snip off the tip of the center stem of the plant. This will encourage the plant to grow bushier.
Continue to trim lower leaves off the topiary. Also, begin to shape the top growth into a ball. About a year from when you planted the rosemary plant, you should have a full topknot on a sturdy stem.
Transplant the topiary to a 4- or 5-inch pot. Remove the plant from its original pot and, using garden sheers, cut away any excess roots. Plant creeping thyme, or alyssum around the stem of your topiary.
Use only sharp, clean scissors. Lightly prune off soft new growth around the edges of the rosemary bush for use in cooking.
Prune back any stems that are growing out at awkward angles or are overcrowding other parts of the plant. Cut them back to the base.
Focus on the lower part of the bush, around the base. Cut back all the branches about 4 to 5 inches from the tips for fully matured rosemary (at least a foot tall). For younger plants, trim it back 2 to 3 inches.
Repeat Step 3 all around the base of the bush until it's even all the way around.
Move to the midsection of the plant and prune it back about 1 inch farther than the bottom branches in order to shape the bush.
Move up to the top of the bush, and trim it back 1/2 inch more then the midsection. Continue to clip soft, new stems as they grow to gather for herbs and to maintain the shape of the rosemary bush.
Rosemary's wands of tiny blue flower clusters tend to erupt in full bloom in mid-spring, generally around late April or early May.
The container must be large enough so that the roots --especially the roots of large rosemary plants -- don't crowd each other out. Choose a pot larger than a number five size pot with greater than a 1 cubic foot volume, preferably twice this size or larger to allow all the herbs to fill out.
Strawberry pots are excellent for growing a variety of herbs. They are open at the top, with several pouch-like openings on the side, staggered so that plants can grow up or trail down without interfering with one another. Half whiskey-barrels are large with treated wood sides transferring oxygen well to herb roots while slowing the onset of wood rot.
Plant the rosemary at the top of the strawberry pot or on a mound in the half whiskey barrel. This area will dry out first, and rosemary roots appreciate the dryness. Plant thyme at the edges of the whiskey barrel so they can cascade over the sides, but on a high pocket of the strawberry pot so they have room to cascade down. Plant basil and thyme in the remaining areas.