You may not notice the aphids until damage is done. You may have new, curled leaves or the leaves might be sticky. There are many species of aphids which to the naked eye are merely different colors. Fortunately the control for all of them is the same. How to control aphids depends on the level of infestation, what they are feeding on and if there are any insect predators present. For instance if I only find a few on a couple of my vegetable plants I am not alarmed but will monitor it closely, except if they show up on squash, pumpkins or melons then I treat right away! In my garden I rarely need to spray for them since I have a resident colony of lacewing that keep them in check. However aphids can be unmanageable on many ornamentals like shade trees, Crape Myrtles and Roses. To control aphids on these I would recommend a liquid systemic that you mix as directed then apply by pouring it at the base and it lasts an entire year!
For a spray to use as needed (but no more often than once per week!) I really like Monterey Take Down.
Hornworms, Budworms and other undesirable caterpillars
You may find small black droppings on your tomato leaves but are unable to find the culprit. Don’t stress, its there and its a Hornworm. They are masters of disguises. You can spray for them or you can hand pick but the moths are always laying eggs so you’re always gonna be handpicking or spraying! If you must handpick, go out in the evening and spray the plant with a hard stream of water. When the caterpillars are disturbed they whip their heads around making them easier to spot. They are also more active in the evening. Once you hand pick them feed them chickens if you have any or squish them. Just be sure to where old shoes because its a messy job!
On ornamental plants like geraniums, petunias and millon bells you may not see the droppings but all the sudden your flowers are gone.
If you prefer to spray, use Monterey Garden Insect Spray. Mix as directed and spray once every 7-14 days.
Whiteflies are hard to find on the leaves but a severe infestation can leave the plants sticky. The first indication that you have whitefly is when the plant is disturbed they will fly. Whiteflies are very small so you will only see small white “flies” or a cloud. They can infest a plant very quickly since they reproduce every 3-4 days! Control is possible but takes diligence. First use a good insecticide like Monterey Take Down and apply as directed. Next in 3-4 days, preferably in the morning but be sure to avoid the hottest part of the day, spray the plant(s) down with a good shower of water. Then 3-4 days later repeat the insecticide. Repeat this weekly process until the whiteflies are gone. It should only take 2-3 weeks.
Snails & Slugs
Snails and slugs can be very sneaky sometimes. They usually leave the tale-tell shiny slime trails but not always. The pattern of destruction on the plant is usually the best way to tell. Snails and slugs are one of the two common pests here in California that can devastate plants in a very short time, sometimes over night! Ever wondered why an entire packet of seeds never came up? Snails and slugs probably ate them as soon as they sprouted! You may have even planted annuals like marigolds then found them to be nothing but stems the next morning…snails or slugs are the culprit!
The best way to control them is to reduce areas for them to hide (like dense groundcover, patches of weeds, debris), keep the areas drier if possible since they need cool moist areas to survive and bait, bait, bait. Snail baits range in longevity once applied, different active ingredients (some of which are very toxic!) and texture of the products. My favorite is Sluggo and Sluggo Plus. These are long lasting baits that are not merely as toxic as other products on the market. You won’t see the dead snails the next morning because when they eat the bait they stop feeding and move away from the area often dying back in their hiding places. I recommend to bait at least a week or two before planting in an area to get ahead of them and prevent devastation on your new plants!
So those are the most common insects encountered in a yard or garden. What insects do you struggle with?
If you have a problem that I didn’t address here you are welcome to bring a fresh sample into The Greenery so our knowledgeable staff can help!