Aphids found on plants - to treat or not to treat?

Thanks for the help in advance!

While I was cutting back the hosta and my calla lilies for the winter season, I've noticed both were infested with aphids. I haven't noticed them a week before.

My questions are:

1. Since I'm already cutting the plants back for the winter, do I still need to treat?

2. Also, I know the female aphids will have already laid the eggs in the soil and the eggs can overwinter - so is there some kind of treatment that I can prevent the eggs from hatching when spring rolls around?

3. Where did the aphids come from? I live on the 22nd flood of an apartment building and check all the plants/bulbs before purchasing them.

4. Unrelated to the aphids, do I need to dig the calla bulbs up and store them in the winter or can they just stay in their pots for the winter given our mild winters?

Thank you so much for the help!!

 

In general, best to treat biologically with natural aphid predators, rather than chemicals. Chemical treatments always miss one or two, but also kill off predators; once the predators are gone, the surviving aphids breed faster and come back in higher numbers than before.

 

Aphids are so tiny that they can hitch rides on just about anything -- not just bulbs, etc. It's just a hazard you have to live with. Stick with non-chemical options and just keep at it. Some years are worse than others: this year was a big one for aphids in my garden too.

Depending on the size of the container you have the callas in and how sheltered the container is from wind, the corms may or may not survive the winter. Containers supposedly bring the hardiness zone down as much as one zone (so if you are a 7 in Coal Harbour because you're near the ocean, your containers are actually living in a zone 6) so you need to weigh whether the zone decrease is likely to kill off the corms. I'd lift them just to save myself the worry, personally. Dry them and put them in a dry place in paper bags until next spring.

Cheers, and good on ya for gardening in the sky!
keke

 

Thanks for all the help!!

I've tried ladybugs before but they just flew away rather than consuming and getting rid of the aphids. Are there any other insects that will help? And, can be purchased from a local garden shop?

As for the callas, do you just cut the stems off, lift them, and brush off the dirt prior to storage?

Thanks so much again!! Really appreciate it!! :)

 

Yes, just cut the callas down, brush off the dirt and dry them (in open paper bag) before storing in a cool, dry place. The important part is to not let them rot or moulder.

Aphids can be hand-squished or removed with a hard stream of water -- they're too weak to climb back up. Not sure you can do the water on the 22nd floor! Insecticidal soap also works on them, but do it every four days in season. They hatch out pretty fast and you're right back where you started if you don't. Of course, at this point no use in doing it. Just make sure you garbage or city-compost the leaf waste to remove overwintering eggs. It won't catch all of them, but most.
cheers
Keke

 

Thanks for the advice!!! I really appreciate it!! :)