It has been A YEAR for aphids!
If your baby brassicas - or those that have gone to seed from earlier crops - have been getting hit especially hard by aphids this season, you’re not alone. Enter the adorable beetle: the ladybug! Don’t be fooled by their cute appearance– they are actually voracious predators, feasting on soft-bodied insects like aphids for their food.
One ladybug can eat upwards of 5,000 aphids in their lifetime–roughly 50-60 per day! Some species of ladybug will also eat other insects like scale, mealybugs, mites, and leafhoppers.
To help them out, set the stage for them!
The aphids will be a great initial lure for them, so you may have seen them more often this season than ever. To attract more ladybugs, plant flowers that they like. They are particularly attracted to white flowers, including white cosmos and plants with umbels of small flowers like cilantro, dill, fennel and yarrow.
Since it’s predicted to be a hot summer, also make sure there is water that the ladybugs can get a drink from near the plants you want to defend (rocks in a small tub can provide them a safe place to stand while they drink). Aphids love a good brassica (who doesn’t?)—these include all sorts of kale, mustards, and cabbages.
Lastly, make sure not to spray insecticides, as most types kill insects indiscriminately and will kill your ladybugs along with the pests they’ll eat. There are alternatives– please see the recipe for rhubarb leaf tea below.
You can recognize their alligator-like larvae that hatch from small, yellow, jellybean-shaped eggs on the undersides of leaves. They scarcely resemble the bulbous, spotted adults! Their larva stage is different too—they look like small alligators. Recognize and care for them during all their life stages.
Help your garden out by working on the aphid population.
50-60 aphids per day may not seem like a lot, but with a whole crew of ladybugs working over your crop you’ll notice a marked difference. Check with your local nursery for some. These have been so popular in the Boise area that they may be hard to find.
If you have curbside city composting, be sure to trim and clear the plants that are most affected by the infestation. For brassicas going to seed, they seem to converge near the blossom. Get those trimmings in the compost bin and clear them out of your garden. If your garden is big (or has a lot going on), chances are you won’t get all of them, so there will still be aphids left for your ladybug friends to continue feasting on.
You can then care for your brassica babies by spraying them directly with water, being sure to clear the leaves. You can try a rhubarb leaf tea if you are playing around with plant ferments as an alternative to pesticides.
Quick Tea:
- Chop a rhubarb leaf, and pour boiling water over it.
- Let this steep for 10-15 minutes and cool to room temperature.
- Strain the liquid into a foliar sprayer and dilute with water - a 1:1 ratio works well.
- Directly spray any aphids off your crops.
- Adjust the spray to a mist setting, and dust all the other brassicas you're growing.
This will deter aphids from settling in on your crops. Spray in the evening to avoid dusting any bees. Apply after rain over overhead watering as often as once per week until the aphids lay off.
Remember to include the plants named above to create that set-and-setting to continue attracting ladybugs to your garden as a great means of natural defense! Here they are again for your convenience:
Cilantro - let it go to seed!
Fennel - let it go to seed!
Dill - let it go to seed!
Yarrow
Rhubarb for the tea
