I live in Toronto and I bought a potted Anouk lavender last month from a superstore garden center. The plant had darker and bigger flowers when we bought it, but now the new buds and flowers appear smaller (almost half the size).
The plant is kept in our balcony where it gets at least 6 hours of direct sun. Over watering does not seem to be the cause, as I ensure that the plant is watered only when the soils appears to be drying out. The foliage looks healthy and the stems appear strong too.
Surprisingly, other plants in our balcony, like gerbera and osteospermum have dark healthy foliage and big healthy flowers.
Wondering what could be the reason.
Hello and thank you for contacting the Toronto Master Gardeners. Let me assure you that what is happening to your Anouk lavender is completely natural, going by the photo you provided and the description of the plant, it looks happy and healthy – but let me explain what you are seeing with the smaller blooms.
Firstly, growers pull out all the stops to ensure that plants are in full bloom when they arrive at the garden centers, just in time to dazzle the gardener eager for colour in their space. To accomplish maximum bloom, they use methods that the ordinary home gardener cannot replicate, such as lights, fertilizers and so forth. The plant also exerts a great deal of its own energy to produce those blooms, and its reserves are quite drained after a full-on flowering. This happens even without the use of fertilizers etc. Any re-blooming plant will put on its best show for the first blooming, after that; the blooms are scarcer and less impressive, you can improve the production of flowers by pruning your plant after blooming.
First, clean your shears with bleach or rubbing alcohol, and cut down plant by approximately one-third. This will encourage new growth and build up reserves for another great show later in the season. You may find the following link useful for pruning your lavender.