Question
QUESTION: I have small flowers on my roses.  Could this be a cultural thing? fertilizer? deficiency? lack of water?


one of my roses   ANSWER: well
some roses have small flowers and some have large flowers so it could be variety. Do they look ok? If they do not look diseased, eaten or funny looking then they probably are supposed to be that way.
heres the thing
please take good care of them by providing a good organic fertilizer esp made for roses. High nitrogen will reduce and or stop bloom production.
I would add rock dust as a source of minerals.
Follow these basic steps
Rock Dust
Compost
Mulch

there are many natural sprays you can use.
try making compost tea and spraying
Milk is also great  for roses
1 cup per 1/2 gallon clean water.
coffee cream and  sugar
make a second batch of coffee (1 gal) to it add 1 cup cream and 1/4 oz molasses.

spray in early am

hope this helps

---------- FOLLOW-UP ----------

QUESTION: The varieties are Peace, Mr. Lincoln, ect.

Answer
Those varieties are not normally very small so I am thinking trace mineral deficiency and high nitrogen.

make sure you are feeding it a good organic fertilizer. Also anything with high nitrogen will make em small if at all (the flowers).

is it near a lawn? Lawn fertilizer will hurt it that way too.