Watering is often the most important gardening task this month assuming we are lucky enough to have a decent spell of dry weather during this late summer period. Plants growing in beds and borders should not need watering if they have been planned originally according to ‘right plant, right place’ principles.
This is simply the idea that, when planning a new planting, the chosen plants are suited to the conditions that prevail in the place where they are being planted. If your soil is free draining and the planting area is in full sun then everything in your planting scheme needs to be able to thrive in those conditions. My greatest inspiration for this concept, one of the greatest plants people of recent times, was Beth Chatto and her books on the subject are a very good place to start when populating a garden.
Unlike plants growing in the open ground, plants in pots and containers will have reached the stage where their roots have completely filled the containers they are confined to and they are completely reliant upon you to fulfil their water and food needs. It is very difficult to rewet compost which has completely dried out so regular watering is a necessity in order to avoid this. It’s also important in order to avoid stressing the plants which will run to seed more quickly, effectively ending their usefulness, if allowed to dry out to the point of wilting.
Any nutrients that were originally present in the potting compost will also have been exhausted by now so adding a feed to the water, following the dosing instructions on your chosen brand, will encourage your potted plants to continue to grow and produce flowers. Regular dead-heading, as always, is essential in order to keep summer displays performing as long as possible—right up until the first frosts if you are lucky.
Dahlias are a case in point. They are only just gearing up to their full potential at this time of year. If kept well watered and well fed they will keep on getting bigger and bigger, with more and more blooms, if indulged and dead-headed. You may have to intervene with some extra support, pea sticks if you have them, as they are prone to collapsing if we have one of those summer storms or unseasonably strong winds.
In fact, going over beds and borders performing judicious editing, cutting back and removing spent flowers, plus propping up anything that is prone to flopping, is another timely task if you want to ensure that your summer displays carry on for as long as possible.
‘Structural’ hedge cutting may commence this month; it’s good to start this task relatively early if you have a lot of hedges to tackle. Those which require frequent trimming can be done anytime, species which are usually cut on an annual basis, yew being chief amongst these, tend to be cut from around now, to late next month, to give them time to ‘harden up’ before the coldest winter weather.
Evergreen hedges and topiary provide the skeleton of the garden, supporting the ‘flesh’ which is the more ephemeral planting around them. Clipping them into shape is another way to keep the garden looking good when a degree of unruliness is beginning to take over. Lawns are another element of the garden which act as a foil to the planted areas. In dry periods it’s a good idea to raise the cutting height of the mower so that the grass is less stressed by being cut too short. It’s never recommended to irrigate lawns as this is a waste of water which should be conserved wherever possible. Even in the driest summer, the lawn will always bounce back, to verdant green, once the rains return.
Rather than just doing regular maintenance tasks, vital though they are, you may also want to try something that is non-essential, but very rewarding: propagation. In its simplest form this is simply collecting and sowing seed from your garden plants, many of which will have set seed by now or will be doing so soon.
A more challenging method of propagation is by means of cuttings. At this time of year shrub growth has had a chance to mature to the ‘semi-ripe’ stage and the hormone levels, necessary for successful rooting, will be at their optimum. This means that cuttings made from these shoots are easier to handle and are more able to survive once separated from the parent plant.
You need to select material from the parent plant which will make finger length cuttings, of a pencil thickness. Remove, using a craft blade or sharp penknife, all but their uppermost leaves and make a clean cut under the last leaf joint. Insert these prepared cuttings into an ‘open compost mix’ (I use a 50:50 mix of potting compost and perlite) around the edge of a pot. Water well with a fine rose on a watering can and cover with a plastic bag over the whole shebang—inserting a cane into the centre of the compost to hold the plastic off your cuttings. Place in a warm, light, position but shaded from full sun as excessive heat is likely to cook the cuttings before they get a chance to grow roots.
In a matter of weeks the cuttings will either have started to root or, pretty obviously, failed to root and turned to mush. They are worth persevering with, even if a fair proportion do not root successfully, as they are plants for free and all you have lost is a bit of time and materials. Try anything that has suitable shoots; spring flowering shrubs are often successful candidates and so are many of the twiggy tender perennials—especially salvias. August is a good time to shear back Mediterranean type sub-shrubs, lavender being the most obvious candidate, in order to reinvigorate them and allow regrowth before winter. These are also worth propagating from cuttings, although they are likely to be shorter than those from larger shrubs.
As a parting shot, and only applicable if you are lucky enough to have one, now is the time to shorten the whippy growths on wisteria to about five or six buds. These long growths are further reduced, to flowering spurs, around February time. Removing excessive growth now encourages the remaining shoots to ripen and reduces the likelihood of the wisteria from being wrenched off its supporting structure during inclement weather. Fingers crossed that the weather this month is suitably benign.
