sbeau, I'd love to be corrected by a garden historian, but my guess is that there are as many answers to this question as there were gardeners during said time period. It's also a practical example of some issues I was just musing about on the recently resurrected "history hopscotch" thread.

Obviously, if you can track down any historical information about your house (photos, diaries, etc.), or nearby houses from the local historical society or library, that's going to be your best source. In the absence of that, I think the best you can hope for is an informed guess. To guide your guessing a bit, I'd start with trying to identify the style and original use of your house and garden.

For kicks, I pulled out a book I just referenced on the other thread, which is entitled "Grandmother's Garden: The Old-Fashioned American Garden, 1865-1915," by May Brawley Hill. I don't mean to convey the impression that this is a definitive source for gardens during this period. Among other issues, the author is trained as an art historian rather than a garden historian, and her examples tend to be limited to individuals who were wealthy enough, or educated enough, to either write about their gardens and/or have them painted or photographed. However, she has captured some interesting anecdotal nuggests.

In the couple of pages that discuss Texas gardens, she notes that "Texas in the nineteenth century was occupied not only by old Spanish families and planters and ranchers from southern states, but by German immigrants, who settled in the hill country [and] cultivated many more vegetables than their fellow Texans . . . .]. Knowing which of these groups, or which other group, your original homeowners fit into would be a starting point. On the one hand, she cites the garden of one Adina de Zavala of San Antonio (1862-1955), who was active in early efforts to preserve Spanish missions and their gardens, and whose well-known family garden included roses brought by her grandfather from France in 1838, when he served as Mexican ambassador. Her garden sounds very lush and cottage-y. On another end of the spectrum, Brawley Hill cites another San Antonio garden dating c. 1860 belonging to German immigrant Edward Steves, that included box-edged flower beds and a cast-iron fountain procured at the Philadelphia Centennial Exposition (1876). They sound like very different gardens.

With respect to the irises, is it possible that they are in the original location but that the tree has grown over time to provide too much shade? Then you are left with the question of whether it is more historically "correct" to leave the irises where they are, or to place them someplace where they might actually bloom, which was surely the historical intent in planting them.

Another book I checked for fun is Alice Morse Earle's 1901 book entitled "Old Time Gardens", which has just been re-released in a new paperback edition (ed. Virginia Lopez Begg). Her points of reference are mostly the east coast of the U.S., i.e. not necessarily relevant to Texas. Believe it or not, though, the first reference to "Irises" in the index is to a passage on white irises! This entry does not discuss placement, but it is quite amazing in its own right--I'll type out a quote below in a second. With respect to (dutch?) blue irises, she notes that these were originally called "Flower of Luce," after King Louis XII of France. In the middle of a passage where she is fussing about the proper name of the plant, she states: "These grand clumps of erect old soldiers, with leafy swords of green and splendid cuirasses and plumes of gold and bronze and blue, were planted a century ago in our grandmothers' garden, and were then Flower de Luce. A hundred years those sturdy sentinels have stood guard on either side of the garden gates--still Flower de Luce." I have no idea whether this is intended as a figure of speech or historical statement, but I thought it was interesting.

Okay, here is the equally poetic passage on white irises that I promised:
The White Iris, the Iris of the Florentine Orrisroot, is one of the noblest plants of the whole world; its ure petals are truly hyaline like snow-ice, like translucent white glass; and the indescribably beautiful drooping lines of the flowers are such a contrast with teh defiant erectness of the fresh green leaves. Small wonder that it was a sacred flower of the Greeks. It was called by the French "la flambe blance," a beautiful poetic title--the White Torch of the Garden."

So there you have a bunch of history, which alas may have little bearing on where you should relocate your flowers, but which I found interesting in its own right. Hope you do too --Kate

P.S. Re: your spider lilies -- my best guess would be that squirrels or other varmints are moving them. This would be known as an accident of history . . .