My Monarchs have all turned to chrysalises now, but my swan plants are not looking very good at all. I would like to do something to help the plants if I can to get them to grow again so the cycle can begin again.
It is a bit difficult to do this kind of distance diagnosis. Is the plant just weakened because the caterpillars have decimated its leaf area or has something else gone wrong, e.g. a disease?
A good general tonic would be a foliar feed with a commercial organic fish fertiliser, also to be used to water to plants. A homemade tonic could be made from seaweed (freshly washed ashore) and stinging nettle. Fill a bucket half with seaweed and stinging nettle approximately 50:50), fill up with water, cover, let ferment for 14 days, stir every day, dilute 1:3 with water for a foliar spray and 1:1 for the watering can to water the plants with. However, as I mentioned before, it could be something else requiring different remedies.