Following last month's Chelsea Chop can come the Hampton Hack. To be carried out anytime now and into next month many perennials will have flowered and will now be looking past their best. Now is the time to cut them completely to the ground. Hardy geraniums, Delphinium, Astrantia, and lupins are good candidates for this treatment. Most will give you a second flush of flowers but if nothing else they’ll produce a healthy cushion of foliage that won’t have the weary time-worn look of plants that have been ignored. It takes a brave hand to clear away foliage that is ‘filling a gap’ but this operation will repay you later in the season. Exposed ground will also give you the opportunity to plant out half hardy annuals such as Cosmos, Helianthus, or Tithonia.
Bending over Backwards
A little trick we discovered by accident several years ago enables you to promote more flowers and cover a larger area with a single specimen of Cosmos by taking hold of the tip of the plant and bending it over and pinning it down to the ground. It works particularly well with specimens that have grown lank and long by being kept in their pots too long. They can even be planted at 35 degrees to the ground. What you're doing here is taking away what is known as the apical dominance from the tip of the plant and distributing the growth hormone, auxin, more evenly along the length of the stem encouraging more side growth and flowers to form.
It’s very hard to hold off sowing seeds and most of us will have sown most of what we purchased in the spring. But Zinnias really are a flower for which an early sowing has no benefit. They love heat but resent disturbance to their roots so your patience will be rewarded now. They can be sown directly where you want them to grow. We like to sow them in drills in the veg garden to use as cut flowers. One centimetre deep, covered, and watered in, they’ll soon be overtaking the seeds your neighbour carefully planted in pots a month ago.
Derby day at the start of June is usually the traditional time to clip your box bushes - spring growth can be removed and the sculptural tightness of this popular topiary plant can be returned. It can however be worth holding off from clipping if you can. An early clipping gives the plant more time to put on further growth as the season progresses leaving you with the necessity to clip again in late summer. If you only have a few box plants or topiary specimens this double clipping may not present a problem, but if you have a furlong of hedging or a full topiary chess-set fit for The Queen’s Gambit then holding off for another month or more will pay dividends later in the year.
Off with their heads
Roses will have been in flower for some time now. Apart from certain shrub roses and ramblers, most will continue to flower for many more weeks so long as old blooms are removed once they have faded and are past their best. Certain roses are grown for their attractive hips too so check on variety before giving a ‘helping hand’ in a friend's garden.