Answer: As long as you didn't change anything from previous years (such as your pruning) then it must just be too early. Lavender seems to perk up when the weather settles and there are long spells of sunny weather. I think it is too early to worry. Another possibility though might be that neighboring trees have grown enough to increase the shade so that the lavender is no longer receiving as much sun as it once did. This could also slow it down and eventually have a negative effect on overall growth and blooming.
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