Been a keen gardner for many years was given a lovely blue hydrangea and would like to know how to keep it blue,also still has some faded blue flowers on, should i cut them of now or not,it is simply not a plant i have had in the past .
thanks in advance.
The blue results from the presence of aluminum sulfate in the soil. Additional acidifiers can make the blue even more intense, but the aluminum is key.
Flower remnants can last a few months. The plants may be pruned as severely as roses. However, the timing of pruning depends on how the plant normally blooms. If it blooms on new growth, prune while the plant is dormant in the winter. If it blooms on old growth, prune right after blooming.
The standard garden hydrangea (H. macrophylla) blooms on old growth. They do poorly in areas with sub-freezing temperatures in winter. That is because the flower buds already exist on the branches before winter begins and are damaged during a freeze. Some other hydrangea species are more hardy, especially those that bloom on new growth.
many thanks for you help
Hi Mossie, further to the very good advice, you may find the following useful. I grow hydrangeas semi- comercially and add 1 oz of lawn sand to the pot in spring to maintain the blue colour. Now lawn sand contains iron in the form of ferrous sulphate, which will give you a blue flower (depending on the variety) but as has been stated, alluminium will give the best blue and for that, if you have no alluminium sulphate, add half a dozen alluminium roofing felt tacks per pot (in the soil) which will last several seasons.
best wishes, Lannerman.
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