Lessons from a heatwave

Sunday, 22 January 2017

Cane begonias like Just Blush have proved survivors in the heatwave

Gardeners perhaps more than many others are acutely interested in, and attuned to, the weather in all its vagaries, as heat, rain, dryness and humidity impact so much on our beloved creations. I am sure few gardeners were surprised to hear recently that several scientific agencies around the world named 2016 the warmest year recorded: the third consecutive year reaching a new record temperature. This past week has been particularly horrific in Sydney, with temperatures of more than 40 degrees in my area - and more forecast to come next week. Coupled with insufficient rain for quite some time, our gardens are being challenged as perhaps never before.

Coleus are doing well despite the heat

I've learned a few important lessons over the past few weeks about trying to meet these challenges whilst retaining my love of gardening. Some of this is a consolidation of my thoughts that have been evolving over the past 30 years as I have attempted to better understand gardening in Sydney. My original dreams of having an English-style cottage garden, complete with all the delightful perennials that flourish so well in the UK, have been finally crushed. The intense heat and humidity spell doom to most herbaceous perennials in our torrid summers - now more than ever. Some of the casualties last week were the vestiges of my cottage garden years.

Part of the summer border with its stalwarts

The heat made my survey my garden to see what was thriving the best. Some of the troopers included Begonia (rhizomatous, shrub-like and cane), Dahlia, Pelargonium varieties, shrubby Salvia, coleus varieties, Plectranthus, perennial Cleome and all the various members of the Acanthaceae family that I grow. Shade-loving foliage plant survivors include Ctenanthe, Liriope, bromeliads of many sorts, Clivia, Philodendron and ornamental gingers - as long as they are in the shade. In a few cases, more sun is reaching some of them these days, and they were scorched in the intense heat of the last few weeks, underlining the point that they are now in the wrong place! I am more resolved than ever to seek out tough, heat-loving varieties - no matter how 'common' they are regarded as - and repeat them around the garden when I have success. Growing temperamental rarities that prefer a different climate is now pretty much a thing of the past for me. However, I've found it is still sort of possible to create the lush, floriferous 'look' of an English border, by using warm-climate plants that thrive in our climate.

Another point that has been rammed home to me is the folly of planting new specimens into the garden in early summer. Though I generally advise against this and beseech people to wait until spring or autumn to do their planting, I did shove a few things into the garden just before Christmas. Suffice to say, those plants, which have had no time to establish, are really struggling at the moment (and some have died), and require extra watering to try to nurse them through these difficult times. I will try to learn from my mistake!

A simple automated controller to water pots via drippers

Having too many potted plants is another weakness I hope to rectify. These require daily (or more often) watering in heatwaves, and who really wants to be outside in that heat? Also, if you plan to go away on a holiday at this time, you need to make arrangements for them to be well cared for by others. We have managed to rig up a simple automated dripper system for the pots this summer, and that has been successful, but I still hope to reduce the number of pots I have.

Too many cuttings like this mean extra work in summer

Taking too many cuttings in spring and then having to look after the resultant plants through summer heat has been another act of madness I've committed. The new plants are in fairly small pots, which dry out very quickly in summer, and thus they need very regular watering in the hot weather - a further nuisance for my long-suffering neighbour when I happen to go away. I plan to do my propagation in early autumn this year and be more ruthless about throwing away prunings: there is surely a limit to how many more plants can fit into the garden!

Cane mulch laid last spring has helped my garden survive the heat

The importance of mulching garden beds has also been emphasised this summer. My garden has survived better than I expected, partly I think because of the cane mulch spread last spring. I have a vague plan to keep the mulch topped up with rough, fibrous compost (mainly partly decomposed prunings that have been put through a shredder) throughout the year so that it is less of a massive chore (and less costly) to lay the mulch in spring.