May gardening tips
Ensure trees or shrubs planted in the last couple of years on lawns or in areas of rough grass have a circle of clear earth around them - this MUST be kept clear or grass will prevent essential moisture getting through. Mulching with bark or compost will help.
Hard pruned clematis should now be growing vigorously - tying the new stems in regularly will prevent a haphazard tangle of new shoots which can break easily.
Cut wispy dead wood on Japanese maples back to healthy wood with sharp secateurs - do not leave any pegs or snags, as these can attract the fatal fungal disease coral spot.
Trim Osmanthus x burkwoodii; which despite that ferocious winter was smothered with scented white flowers in March and the first half of April. Prune forsythia and ribes (flowering currant) too, if you haven’t already done so - cut a proportion of the oldest, tallest stems right down to the base.
Twist off the spent flower heads of rhododendrons and azaleas and mulch with composted bark, garden compost or leaf mould after watering if the ground is dry. Feed with an acid feed.
Feed acid loving plants such as camellias and rhododendrons with ericaceous feed if you are on neutral or alkaline soil. A dose of sequestered iron also helps prevent the leaves turning yellow. (Tip - mulch regularly with fresh or composted pine needles. This can acidify the ground slightly.)
Spray roses with fungicide to ward against black spot and mildew. Repeat every fortnight until the autumn. Remember that if an infection sets in, all the stricken leaves must be burnt - do not leave them on the compost heap as this will become the perfect incubation site. Feed with a foliar feed and beware greenfly - treat immediately if an infestation occurs - ask in the garden centre for advice as to what to use if you are unsure.