early butterfly nectar
Several days ago there was a black swallowtail butterfly (blue tail so assume eastern) flitting through garden. It landed for seconds on many plants, but never on iberis/candytuft or helleborus foetidus which were only ones in bloom. Given our erratic weather, is there anything we can do to provide food before their nectar available?
There are many lists of butterfly nectar sources for this area. Here's a local one: https://washingtonareabutterflies.files.wordpress.com/2012/09/what-do-caterpillars-eat.pdf These lists are not exhaustive.
Try to grow a variety of plants. Remember that some trees, for example wild black cherry, are early and great nectar sources. One tree is a bonanza of nectar.
That source and others do not address the bloom TIME, which is what i asked. And i beg you to reconsider recommending black cherry given the certainty of black knot. BTW, i forgot to mention that the plant that butterfly went to most was several "clumps" of rue, which were not in bloom, but nevertheless have a distinctive scent.
Take a look at the following publication, which addresses pollinator plant bloom time from early to late season.https://xerces.org/wp-content/uploads/2016/10/2017-049_Mid-AtlanticPlantList_Dec2017_web-3page.pdf
There are additional plants -- and season of bloom time -- listed here:
Black swallowtail butterflies will lay eggs on plants such as rue, parsley, fennel, cilantro, and dill. You can read more about their preferred host plants here: https://entnemdept.ifas.ufl.edu/creatures/bfly/bfly2/eastern_black_swallowtail.htm