Wilde side

Kim Wilde answers your gardening questions.

How can I make my pale blue hydrangea flowers a deeper blue shade, and my pink ones a deeper pink? This year, I used sulphate of potash on the blue ones and there was a definite improvement. The pink also improved, but the colour is still rather pale.
All blue hydrangeas are naturally pink. The emergence of blue colouring depends on several things: the variety, the soil and water quality, which should not be calciferous (rainwater is preferable). Flowers achieve the deepest blue tones in a soil of pH 4.5-5.5. Aluminium sulphate is a blue-ing compound, which can be added to your already acidic soil to intensify your blue colour. This should be raked into the upper part of the soil every year in September. Pink or red varieties can turn blue on acidic soil, so a dressing of ground limestone (applied annually in winter) will preserve the pink colouring. Conversely, they won’t appreciate rainwater, but instead prefer tap water.

How do we get nice old-fashioned daisies to grow in our lawn?
What a delightfully unusual question. Bellis perennis is the humble lawn daisy – the kind that flowers all summer and is strung together in chains by children. Plug plants are available from wildflower specialists such as British Wildflower Plants, in Norfolk (01603 716615). Ideally, plant them between September and May, and they will quickly multiply in a sunny position – they germinate in 48 hours.

My shrub roses always grow back rangy after pruning. How can I encourage them to grow bushy (I feed them with horse manure in autumn)?
Compost and manure improve the structure of the soil, rather than providing nutrients, and roses are hungry plants requiring nitrates, phosphates and potash. Manure is a good source of nitrogen, but it promotes leafy growth and is probably assisting the ranginess of your roses. Your best bet is to apply a ready-mix rose feed, and remember: experts never feed their roses later than July.