Dead head your Meconopsis as soon as they finish flowering. If you let the seed head grow and develop the plant will quite naturally die. Removing the seed head saves the plant energy and it will reappear next season. It is advisable to do the same with the tall seed heads on Candelabra Primulas too.
Prune the dead flower heads out of your French lavender – Lavandula stoechas. If you do this on time the plants will grow on and produce a second set of flowers later in the Summer.
Callistemon finish flowering now. The plants will now waste a great deal of energy producing large round seed pods all along the stem. By cutting out the flower heads will encourage the shoots lower down the branches to grow on and flower better next year.
One of the most frequent gardening queries we get is why Wisterias take so long to produce flowers. The reason is that they expend too much energy growing long trendrils of new growth.
Immediately after flowering, when the spurs and tendrils of new growth are growing away exponentially, is the time to ensure good flowering next season. You are aiming not just to train and control the plant as and where you want it to grow but, more crucially, to avoid the plant wasting energy on new growth shoots which will not produce any flowers next year. So prune out the soft and whippy new growth to about 6’’. Leave unpruned the growths needed to fill the trellis or wires in the shape you want. There may well be a lot of new growth to remove and this includes growth and vigorous shoots from the base of the plant or even from root suckers at ground level where the roots are forced above the soil level and exposed to light. This is common in older wisteria.
If your soil is acidic (peaty/loamy/normal) as opposed to alkaline (chalky) why not try out the very best new blue hydrangeas – ‘Taube’ (lacecap) and ‘Enziandom’ (mophead).
Propagation by semi-ripe cuttings
July and August are ideal times to cuttings in the garden and create plants for free for yourself or friends.