First you need to decide if you want the grounds to be historically accurate.  There is a great deal of research available -- from the National Park Service on down -- on what plants would have been in a historic garden from your time period.  (Hint: clover was not one of them, it is also impossible to remove once you have it.)

A good, accurate, and easy starting point are herbs. If you are in central or southern NM you can start them this fall. If you are in northern NM wait until spring.  Herb gardens functioned as kitchen and medicinal gardens for the residents, so think rosemary, cilantro, dill, lavender,  fennel, even amaranth would have been accurate for your area. Most herbs are perennial (come back year after year), so they become low maintenance. 

Next, think about food crops for the kitchen plot. New Mexico is the perfect place for a 3 sisters garden and you can talk about the Native American agriculture.  https://aces.nmsu.edu/pubs/_circulars/CR457/welcome.html

Finally, talk to your local Master Gardener group --  https://aces.nmsu.edu/ces/mastergardeners/  They MUST have service projects to maintain their MG status and museums are some of their favorites.  They will put in whatever you want.   And, they will likely be willing to help with the Spring festival you are thinking about. Trust me, gardening with kids is NOT as easy as you want it to be! 

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