Aphids overwinter in soil?


I had an issue with aphids this year on my squash, cucumber and lettuce in particular. I have pulled all the plants out of my garden and have added some compost. Today I noticed the aphid “trail” (clear/sticky substance) on the soil
My concerns/questions are:
1. Can aphids overwinter in the soil?
2. If so, what is the best way to get rid of them now? (I have tried nematodes so far, didnt seem to work)
3. I am unclear about mulching my garden before winter. On one hand I read that you can use leaves to mulch and on the other hand it is said that this can create habitat for aphids… I’m not sure what to do, but would like to rake my leaves into the garden if possible.
Thanks for the help!


Most aphids have a similar life cycle and it is their eggs that overwinter on standing plants, not adult insects. Look for masses of eggs and blast them off with the garden hose. (Similarly, in the spring and summer, when adults are present on your plants, blasting them with water will remove them.) At this time of year, it is likely that the trail you saw was the product of snails or slugs.

OMAFRA has a good guide to aphids on vegetable crops here.

As for saving your leaves, good for you! However, just raking them whole into the garden is not a good idea. In our Gardening Tips for this month, we advise “Rake the soggy masses of leaves off your garden – chop them up and return them to your garden as a cozy blanket for your soil during the winter.  The chopped leaves will decompose and add valuable nutrients to your soil.  They can also act as a mulch and protect your plants during the freeze/thaw cycles.” If you don’t have a lawn mower to run over the leaves and chop them, you can also use a string weed trimmer to chop bunches of leaves in a garbage can.

You can also save and compost your leaves (and your neighbours’, too!) Rake leaves into a single pile and surround with a simple barrier to keep them from blowing away. A 2-metre pile of leaves will break down dramatically over the winter. Or you can save leaves in plastic garbage bags; each large bag will hold enough for a month or so of composting. If you are able to shred the leaves first, as described above, the composting process will begin immediately.