Wednesday, June 28, 2017

I'm in! What do I plant?

Native species of plants were removed from your site when it was initially developed.  More may have been displaced by the landscaping decisions of people who owned the property before you.  It's time to put them back.

Native plants support native animals.  It's that simple.  To restore the ecosystem that existed before your house was built, you have to put back the native plant species your local animals need to eat and to build their homes from or in.  Plants are the bottom of the food chain.

Because plants can't walk themselves to your location, if they are gone, it's up to you to find them and plant them.   This blog is going to be about what's local to Malden, Massachusetts in the United States, but the principles are the same for anywhere.  Find out what plant species should be in your space that aren't any more, and put them back.

The spiderwort begins to bloom.  All the species in the Tradescantia genus are native to the New World.  They hybridize readily with each other in the wild, and have a lot of natural color variation within each species, so it can be hard to identify which one you are looking at for sure.  But because they are all local-ish, any of them is a better choice for my garden than a plant from Asia, Europe, or Africa.  They open their flowers in the cool of the morning and evening, and close them when the sun gets fierce, so planting them where they get some dappled shade will give you a better floral show.  
As soon as the spiderwort began to bloom, these small flower flies, (Toxomerus marginatus) appeared.  Here, a male waits for a female.  Adult male insects often have larger eyes or other sense organs than females, the better to detect a potential mate.  From this angle, in this picture, this male's eyes look like a uni-eye.  Males often reach their adult stage and have only a few days or even a few hours to find a mate and pass on their genes before they die.  They have to search out a mate as soon as possible.  Male insects also often have smaller or slimmer abdomens than their female counterparts, because they don't need internal space for eggs.  

Female Toxomerus marginatus arrive at the newly opened flowers to collect pollen.  Spiderworts are an example of a nectar-less flower.  The pollen itself is an ample reward to pollinators.  Nectar is a carbohydrate source and pollen is high in protein, but often plants with this particular pollination strategy produce pollen with an especially high protein content.   Once they reach adulthood, many female pollinators need extra protein to help their eggs develop properly.  In addition to eating the pollen themselves, some pollinators also collect it and take it back a nest where they shape it into "bee bread," which their offspring will eat when they hatch.  T. marginatus seems to just be eating this Tradescantia pollen.  She doesn't have any obvious pollen collecting fuzz on her body that would help her transport a load of groceries back to a nest site.  
And a little later we find out why.  Instead of building a nest, here she is, scattering eggs across the surface of a Helianthus maximiliani (Maximilian sunflower) leaf, another Massachusetts native plant.  Her unbelievably tiny eggs look like pollen grains themselves, at a time of year when every surface in the garden is dusted with pollen from the trees.  They are hidden in plain sight.  When they hatch, the larvae will feed on aphids, thrips, or small caterpillars on the plant they were laid on, so it is important that they are laid on another native plant:  one that is hosting a variety of herbivores for the devouring.  These little hover flies are important predators in their youth, and minor pollinators as adults.  



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