carlos,
"dates reported by "some" nurseries they may be designed to induce buying"
too true!
much of the information about avocado trees we see on the web is provided by those who are trying to sell avocado trees. caveat emptor!
the wurtz that i have was a nice, healthy three gallon grafted tree from top tropicals in ft myers. i put it in the ground last spring (may? early june?) it has done well and even grown a little. wurtz is a dwarf with short internodes, so it is not a lot bigger. presently, it is about five feet tall with a trunk about 1.5 inches (3.75 cm) in diameter where it emerges from the soil. it has a lot of buds at/near the ends of the branches, but they have not gotten to the stage where i can tell if they are leaf buds or blossom buds. i suspect that there may be some of each. there are enough buds that if they all turn out to be leaves, i will have a VERY bushy plant!
with the mexicola, i saw flower buds about a month before i saw one open (today). if this time pattern holds true with the wurtz, i can expect the first flower to open about a month after the time when i can see identifiable blossom buds. so far, i can't see blossom buds, and i can't make a good guess about when i will, so i can expect wurtz flowers after a waiting period of one month PLUS an unknown amount of time. that's kind of open - ended.
once i do get a wurtz blossom, i CAN make a guess about maturity time. judging from other varieties, blossom to maturity takes about seven to ten months, give or take. that's a little indefinite, but not quite as loose as the date for the first blossom.
there are even more uncertainties. the dates listed on the web by nurseries and university ag departments are based on conditions either in california or in south florida (plus a few australians). NOT ONE source on the web is basing their dates on conditions that prevail in a greenhouse in north florida.
when will my wurtz have a ripe fruit on it? the real answer is that i don't know. but i can make a projection (not a prediction). picking a date out of the air, i'll say that IF (remember that word) i get a blossom bud on the tree on the vernal equinox - march 21st, i MAY get a blossom sometime late in april, which, IF the bees are on duty, MIGHT turn into a ripe fruit sometime between christmas 2014 and memorial day 2015. maybe. remember, the real answer is that i just don't know.
...or, my wurtz may not bloom at all this year, and i have to add a year to all those dates.