Is it normal for some of the flowers on a lemon to be imperfect? I would guess about 20 to 30 % of the flowers on my lisbon lemon do not have a pistil.

I have observed the same for Meyers too.

It is not uncommon in some varieties, that a percentage of the flowers have abortive pistils whose development was prevented, or interrupted at various stages of development by the competition of other flowers for food materials. The flowers of a fertile citrus variety may be either (1) perfect (hermaphroditic) or staminate (male). In the case of Citrus Limon, C. aurantifolia, and C. Medica the pistil is regularly underdeveloped or totally absent in a large part of the flowers. The proportion of staminate flowers (male only flowers) is highly variable, according to the variety and the growth conditions. The stamens, unlike the pistil, show very little tendency to general failure of development, although in Navel Oranges part of the stamens are often abnormal. If you have volume 1 of "The Citrus Industry" you can read about flower sterility on pages 804 and 805. - Millet

Thanks-- There are lots of blossoms so competition for nutrients could be a factor. Also, I did not fertilize until March and many of the blossom buds had started showing in early Feb.

Based on the recommendation from LSU to fertilize in Jan., I am thinking that the fertilizer does not actually stimulate growth, but just supports it and fertilizing in the middle of winter would allow the roots to get ready for the spring flush which is actually driven by temperature--any thoughts on that?

It would not be appropriate for our area. We get a lot of rain during the winter. If we apply fertilizer during the middle of winter, the fertilizers will be pushed out beyond the rootzone and would be wasted, causing instead severe ecological disaster on runoff streams and the ocean. The best time is late January or mid February. The last rains of the season should push the fertilizer down into the proper depths in the root zone. If there are no late season rains, there is that garden hose anyway.

According to published information, it is important to understand that it is warm winter temperatures, not irrigation and not fertilization, that play the major role in stimulating untimely winter flushes of large, mature trees. However, when unseasonably warm temperatures occur, young trees may flush more easily than larger, mature trees, especially trees planted the previous fall. If such young trees flush during winter months, fertilization may stimulate additional, tender growth, making trees even more susceptible. One must consider the degree of flush, tree size, time of year and geographic location when making this decision. You can read about this on page 16 of the "Your Dooryard Citrus guide." - Millet

Thanks again Millet-- as you say--I think it is important to understand the real driving force here is temperature and age of the tree. I will probably start fertilizing my older trees in mid Jan next year.