Spring is here and it's not too soon to start spraying and treating for insects. This is the time of the year that I treat the entire yard with a spray made of soap and canola oil. Skipping this step has caused major problems for us in the past. Prevention is much easier than treating a problem after it has developed.
In developing our protocol, we had to take several things into consideration. The first is our pond. With koi, we are restricted from using anything that is toxic to aquatic life, and that eliminates most chemical sprays. We also have a lively population of both damselflies and dragonflies, and our garden teems with bees and butterflies as well, all of whom are also sensitive to many chemicals.
We prefer to spray in the evening but when that isn't an option, we spray in the very early morning (as soon as it's light enough to see - around 5:30 AM) before the bees arrive. The honey bees from an apiary not far from our home visit daily to collect pollen, especially from our lavender and roses. The bees are welcome visitors to our ecosystem so we spray either a few hours before they come or after they return home for the evening.
Spraying with garlic has eliminated fleas from the area and the rose geranium oil is a very effective tick repellent. We were unable to find geranium oil early in the season last year so our sprays did not include it until the middle of the summer and the number of ticks we had to contend with was significantly greater compared to years when we've sprayed with rose geranium oil at the outset. We usually begin spraying for ticks by the third week of April and continue every three weeks or sooner if we have several days of drenching rain.
Cathy’s General Garden Protocol
Step 1: Dormant Oil Spray
This can be applied in the fall (October or later) or in March or April. (Wait until there is no more snow on the ground. It’s okay if it snows after you spray, as long as the oil is able to dry on the plants and ground for 24 hours without snow.)
Mix ¼ cup of Canola oil and two tablespoons of clear soap per gallon of water and liberally spray the entire yard, including trees and the beds around any plants that remain. The purpose of this is to smother insects and their larvae while they are in a dormant stage.
Step 2: Ammonia Spray
This should be applied in April to all beds to kill fungal spores and beetle and other pest larvae, and then weekly or every other week to the beds around Asiatic lilies (for control of red lily leaf beetles) beginning in May. Wait until there is no more snow on the ground and you are reasonably sure that it won’t snow again. Spray the beds – specifically, the surface of the soil or compost – not the plants (will not hurt the plants but won’t solve the problem you are trying to treat either!). Use a 10% solution of plain, household ammonia. That means one cup of household ammonia to 9 cups of water. Dampen the surface of the soil in the beds. If you have a lot of black spot, this is really a good way to help stem the tide. Otherwise, you’ll keep getting it every time it rains.
Step 3: Corn meal/cracked corn
This should be applied in April or May to all beds that have plants that may be affected by blackspot and other fungal infections. Reapply in 8-10 weeks if it is very rainy and again in the fall when mulching for winter.
Blackspot primarily affects roses, but I have seen it attack tall garden phlox and peonies as well, so we generally put it down in all beds just to be sure, especially since a contaminated leaf from one bed can easily blow into another bed and cause a major problem. We also reapply in the fall, when we lay the fall mulch. We use coarse cracked corn (chicken feed) and sprinkle it generously then cover with our home made mulch (composted leaves). To apply this, sprinkle it generously before you mulch, and then top-dress with about 3 inches of fresh compost/black mulch.
Step 4: Rootshield WP Spray
Like cracked corn,
Rootshield WP spray provides a biopesticide that is effective against blackspot. We spray all of our roses, peonies, phlox, and any other plants that have shown signs of fungal infestation with a solution of 1 Tablespoon
Rootshield WP powder dissolved in one gallon water in May and September and 1/2 Tablespoon
Rootshield WP powder dissolved in one gallon water in July.
Step 5: Milky Spore
This should be applied in May and October to all beds where you see Japanese beetle grubs (large white cut worms). Reapply in late June if necessary.
Step 6: General Garden Spraying
This should be started in late April or early May (after the last snow and when the gardens are starting to show some active growth, usually when temperatures are consistently above 50 degrees during the day) and continue through September. I may alter the schedule and the ingredients if I see a particular pest. See the recipe and protocol below page. This takes care of virtually all the usual garden pests including fleas and ticks, and is safe for use around pets, children, birds, butterflies, honey bees, and fish.
Cathy’s Blend for General Garden Spraying
In a one gallon sprayer, mix the following:
8 ounces of home made botanical tea concentrate (recipe below)
2 ounces of garlic oil concentrate (recipe below)
2 ounces of citrus oil concentrate (recipe below)
2 ounces Green Light Neem Oil Concentrate – available at Lowe’s
2 ounces of Green Light Organic Control Concentrate – available at Lowe’s
4 ounces of canola oil (any brand, canola cooking oil)
2 ounces of Seventh Generation all-Natural Dish Liquid - available at Lowe’s, Shaw’s, Albertson’s, Wal-Mart; pure castile soap or any all natural dish liquid will do
2 Tablespoons of Baking Soda
15 drops of rose geranium oil
Add water to make one gallon of solution
(Green Light Organic Control Concentrate contains Thyme Oil, Clove Oil, and Sesame Oil.)
Spray liberally at dawn or dusk when there is no rain expected. If we spray in the morning, we spray at about 5:30 AM. If we spray in the evening, after the beginning of May, we wait until 7 PM or later.
To make garlic oil concentrate:
Finely chop the cloves of 4 medium to large bulbs of garlic. Peel the outer dry, papery covering away from the cluster of cloves and cut off the root base, but there is no need to peel the individual cloves themselves. (I use a small food processor/chopper for this.)
Soak the minced garlic in 8 ounces of soybean oil. (Crisco and Shaw’s brand – check labels) for at least 24 hours. (I usually let it set quite a bit longer, but keep it in the refrigerator.) Strain into a clean jar. When you strain out the garlic, you’ll lose a little oil, so I add additional oil to make a total of 8 ounces. That gives me enough oil for four batches of spray.
To make botanical tea concentrate:
Make peppermint with four cups of fresh chopped stems and leaves or two cups of dried herb in four cups of water. Boil for ten minutes, then let the tea steep for at least 2 hours. (I boil it and then just let it sit on the stove until it’s cool.)
Make botanical teas of each of the following with 1-1/2 cups of fresh chopped stems and leaves or 3/4 cup of dried herb in 1-1/2 cups of water of the following herbs and flowers. Boil for ten minutes, then let steep for at least 2 hours. Strain all teas, mix together and save in a large container in the refrigerator. Gallon water jugs are perfect for storage. If you will use the solution in a day or two, you don’t need to refrigerate it, but to keep it any longer than that, you need it refrigerate it or it will get moldy.
Chives Rose geranium (pelargonium)
Rosemary Marigold leaves and petals
Cat mint Sage
To Make citrus oil concentrate:
Mix the rinds of citrus fruits with just enough water to cover them and simmer for 30 minutes and then steep until cool. I usually make 1-2 cps of this for each gallon of concentrate. I save orange, lemon, lime, and grapefruit rinds in the refrigerator. When I don’t have any citrus concentrate, I have used dried lemon and orange zest, one tablespoon zest plus ¼ cup of lemon juice.
Note: You could probably make all of your teas together but I make each tea separately because some are more effective at treating different problems and for me, with my extensive gardens, I sometimes want to tweak the spray if I see a particular problem in a certain bed. Also, I tend to make larger batches and it’s easier for me to save it in individual jugs and then blend it when I am making a few batches of spray. (I use empty plastic water bottles.)
I keep the concentrate in the refrigerator as it does go bad. We use a two gallon sprayer now and it goes very, very quickly.
The odor of the garlic dissipates in a matter of minutes. The oil and soap remain on the leaves and they look shiny and healthy. If the oil doesn’t adhere to the leaves, the spray won’t be effective, so do shake the container frequently as the oil settles out. The rose geranium oil is the single-most effective repellant for ticks.
If you see powdery mildew developing on your peonies or phlox in between spraying, mix up a small amount of soap, canola, and a tablespoon of baking soda in a quart spray bottle and spritz the entire plant wherever you see it.
I spray weekly and my spraying schedule is on a three week rotation unless I see an infestation of something. Then I will add either a few isolated ingredients, or use the full recipe.
Week 1: Full recipe
Week 2: Garlic oil with canola and soap
Week 3: Peppermint oil with canola and soap
When the red lily leaf beetles start in spring and the Japanese beetles arrive in July, I do add Neem to both the Garlic and Peppermint sprays and spray with it weekly as well. You may have to pick off a few adult red lily leaf beetles but if you can get the spraying started before the first wave comes through, you’ll be fine.
Japanese beetles prefer to fly when the temperatures are above 85, so pick off adults that arrive and then spray with Neem. (I make a spritz bottle of 1 ounce Neem to a quart and a half as that’s the size of my bottle, then spray where you see them. They mostly attack the roses and hollyhocks. Apply milky spore wherever you see grubs when cultivating and this will help keep them to a minimum. Do NOT use Japanese beetle traps. They attract more beetles than they catch! If your neighbors hang them, ask them to put them on the far side of their property away from yours!
Lastly, if the RLLB’s are a real problem in your area, spray the dirt under your plants with a 10% ammonia solution. This kills the larvae. It’s safe for roses too and can help minimize black spot. I do use Bayer garden spray if I have a huge infestation, and that kills them on contact and also kills the larvae, but be sure to get under the leaves as well, and I also spray the ground. These are a real problem with Asiatic lilies, but they will migrate to other plants as well once they have decimated your lilies.
You’ll notice that I don’t use pyrethrum. Pyrethrum is derived from chrysanthemums and although it is one of the most potent and effective “natural” botanical pesticides, it is highly toxic to fish. With our koi pond, it simply isn’t safe for us to use.
Author's Note: This protocol was reviewed and updated on 6/21/11.