I have a Katherine Havemeyer Syringa
Staffordshire,
United Kingdom 
I will keep an eye on it.
Thanks for the info.
10 Mar, 2025
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« It could also be a Virburnum Dawn apparantely, that has a slight scent. Well,...
As you are nurturing it by feeding it and it has put on plenty of green growth it may be too happy. Many plants will only flower well if they think they might fail so need to flower and set seed to reproduce. So, I would only feed with Sulphate of Potash which will encourage flowering at the expense of green growth.
10 Mar, 2025