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.

Reader Comments

  • By Robyn 3134 Monday, 23 January 2017

    Our best permormer by far is an ornamental grape vine. It gets no watering apart from rain. It never wilts or scorches in the sun and just grows and grows. It has a wonderful permume in spring and occasionally in summer - so wonderful that I cut a huge bucketfull of blooms and have made wine out of it. In a month or so I will put it into champagne bottles and ferment some bubbles into it. It autumn when the evening sun shines through it, it is stunningly crimson. Sounds fab, Robyn. They do well in Sydney too. Deirdre

  • By Janna 0 Monday, 23 January 2017

    I"m not sure if 40 degrees or minus 4 is better! It certainly seems to have been extremely hot in Sydney this year. I so love what you have managed to create in your garden; so much cheerful colour using plants that actually want to be there. I do hope it cools down soon so you don"t lose any more plants. The way I feel at the moment, Antarctica or at least Macquarie Island are looking very appealing! The heat has been unlike anything I remember experiencing before in Sydney and I have lived here all my life! Do hope all is going well for you and that the weather warms up there soon! Deirdre

  • By margaret 2122 Monday, 23 January 2017

    Sydney"s weather has been very trying lately. My garden is surviving quite well, mainly, I believe because of a few principles I apply during the year: mulching, using "drought shield" to protect vulnerable plants, using a wetting agent and close planting. A couple of surprise plants not faring well are some zinnias, stokesia, Marguerite daisies and some pentas. Begonias, gerberas and coleus are among plants coping well. Thanks for your tips, Margaret. I think the intense humidity is affecting some plants that would normally stand up to the heat OK. Deirdre

  • By Maree 2074 Monday, 23 January 2017

    We have recently returned from Cambodia and Vietnam and whilst there I became convinced that the best type of garden for us is using tropical or semi tropical plants. I don"t think I would ever plant another camellia, rose or azalea again. I do think semi-tropical plants are the way forward; but I must say my established camellias are holding up well. Deirdre

  • By Beth 2257 Monday, 23 January 2017

    Guilty, guilty guilty! I am a compulsive user of prunings and visitors love to take away a pot or two... BUT each summer we visit my mother in law on Norfolk Island for 2 months so my very patient neighbour (says she loves visiting my garden!) has been beside herself keeping up with visits to check on the plants. Despite using mulch, newspaper sheets and woodchip and an irrigation system extensively I have still lost some plants. I return home next week and am stressing in advance! Do hope you find things are OK after your return from the trip. I am trying to be philosophical about plant losses. It has just been SO extreme this January. Deirdre

  • By Bren 2540 Monday, 23 January 2017

    I couldnt agree more! I have reduced my potted plants to caudiciforms almost exclusively; if I can plant a plant in the ground rather than a pot I will do so. I have one area of the garden where I plant "indoor" plants, which I am prepared to water every second day; all other areas are subject to natural selection. And i have sworn not to buy and plant anything new until autumn. It"s about reducing work load! (Aren"t cane begonias tough, by the way!) It is certainly a good test of our plants. I admire your strategy. Yes, cane begonias are truly fab in our climate. I may get some more of them at the begonia show this year! Deirdre

  • By Sandy 2482 Monday, 23 January 2017

    On the Northern Rivers we have had very similar weather to Sydney the last few months. I identify with your observations about too many potted plants and too many cuttings in heat waves. We are on tank water which was one rung from running out when the wet season arrived on 3rd January so we were watering sparingly by hand and when you are about to run out of water you are forced to choose carefully based on each plants apparent stress. Nothing died in the ornamental garden, but veges! Very challenging for you with tank water being your source of supply. I recall my grandmother (also reliant on tank water in the country) saving washing up water and even water from cooking veggies to water her plants in times of severe drought. Deirdre

  • By Carole 2264 Monday, 23 January 2017

    ....what has coped best can only be the most established shrubs, and they do have sugar-cane mulching, and they still need regular watering. Pentas, salvias holding in there too. My little potted cuttings have been sheltered and like you say, those tiny pots need consistent plunging into a plastic laundry dish that I have half-filled with water; sometimes left there overnight and out the next morning. Am also thinking how best to modify hard to water/difficult to reach areas with succulents. Your strategies sound good. I like the idea of the laundry dish to really water the little pots properly. I have mine sitting on a bench with an old beach towel underneath them. The towel seems to hold enough moisture to sustain them when I am away for a day or so. Longer than that I need my faithful neighbour"s help! Deirdre

  • By Marilyn 2250 Monday, 23 January 2017

    You are spot on as always Dierdre. I"m doing a body count myself. Even spending a small fortune on irrigation is no substitute for rain. I"m veering towards trees and shrubs. Oaks, conifers, some Camellias, Loropetalum, Crepe myrtles, Acers (some), holly, Prunus, Pyrus, Liquidamber to name a few. We have hundreds of species of trees, shrubs and perennials (we are one of each gardeners). Happy to make a list of recommendations if you are interested. Thanks for those suggestions, Marilyn. I agree that established shrubs and trees seem to be coping much better than the smaller sorts of plants. Deirdre

  • By Christine 2429 Monday, 23 January 2017

    Thankyou Deidre....too anxious to plant out early Summer was not wise. All those new garden beds too tempting (renovating garden at new place). The salvias have done well, japanese buxus both japonica and microphylla are sooo tough here. Just ordered a dozen small - to 1m or so - pink oleanders so hope will do well. Some cordylines have burnt badly, were well watered, poss. part shade would have been preferable. Thanks for blog.Learnt a lot. I think the oleanders are a great choice, Christine. They grow so well in my grandmother"s old country garden. Good to know how well the buxus are doing for you too. Deirdre

  • By Gail 2086 Monday, 23 January 2017

    Ornamental gingers can adapt to increased sun conditions. I planted several clumps of the fragrant white ginger in the semi-shade conditions provided by tall eucalypts. These trees were subsequently cut down, and the ginger did scorch on the first extremely hot day. However, I simply cut it all back and new shoots soon followed. The shade did not return, however, but the gingers adapted to the sunnier conditions and have continued to thrive. Interesting about the gingers; they seem to be resilient plants and I didn"t know they could adapt to sun. Deirdre

  • By Bev 2745 Monday, 23 January 2017

    Ditto ,ditto,ditto! I love cottage style gardens & also have far too many pots. Iceberg roses ,gingers,cleome seorita rosalita,euphorbia ,pride of madeira,cannas ,cone flowers & salvia are all doing well. I agree with all those ones - they are tough! Thanks for your feedback, Bev. Deirdre

  • By Sue 2074 Monday, 23 January 2017

    Totally agree with all your comments and those of others. Too many pots and cuttings (waiting in the wings to fill my daughter"s garden). Apart from the plants you mentioned which I also grow, are tall asters, tuberoses, lamb"s ears,pinks and the toughest of all shrubs ceratostigma willmottianum which self-seeded in the crack of a large rock.Don"t know which is worst the heat or the 5 scrub turkeys chicks which are living in the garden and scratching up plants! Yes that ceratostigma is an amazingly tough plants. Aargh ... those chicks are so annoying. They are kind of cute when they first hatch but rapidly become just as pesky as their parents! Deirdre

  • By Kerrie 2104 Monday, 23 January 2017

    I"m surprised how well my new garden has done considering how many days over 30c we"ve had but we are on the coast where it"s a bit cooler so that"s a big help. I also water 3 times a day in extreme heat. Plants doing well are Cannas, Osteospermums, Gazanias, Gingers, Begonia Bleeding Hearts, Heliconias, Rain Lilies & Cat Whiskers. Surprising not doing well plants,California Poppies & giant sunflowers. Foxgloves, Delphiniums & Lupins sruggling but they are perannials. I think that coastal breeze does help. I do think many of the cooler climate perennials are knocked by this sort of intense heat. Deirdre

  • By Kerrie 2104 Monday, 23 January 2017

    I"ve bought sone new plants on sale that i have in pots until i plant them in Autumn but when it"s really hot i put them in the garage which is under the house so it"s nice & cool in there.Its my new garden"s first Summer so in Autumn i"ll move things around, replant & refine it now I"ve learnt from Summer. I too am looking forward to autumn when I can plant things again! Good luck with your new garden. Deirdre

  • By John 3030 Monday, 23 January 2017

    We have had some really hot weather in Melbourne too. The golden diosmas have handled it well though. I"d be interested in more information about how to set up a simple watering system for pots and raised garden beds. For the garden beds we have the brown dripper hoses; these are arranged in zones with a master controller switch that turns each zone on in turn twice a week.For the pots we have thin tubes that have a dripper on the end; the thin tubes are connected to one long larger pipe at the back of the pots and it is controlled by a simple timer that makes the tap come on for a certain amount of time every 24 hours. The pots system is quite simple and all the bits were bought at a big hardware shop. The other system is more complicated but we did install it ourselves. Deirdre

  • By noeline 2081 Monday, 23 January 2017

    I agree the Begonias are splendid this year also the ivy pelargoniums are full of flower I have found my renga renga lilies droopy and sick looking in the heat but I hope a good chop back will fix that.I am leaning towards putting more succulents in in autumn as two of my lovely leucodendrons turned up their toes in the humidity. My renga rengas also do not look great, where they have received too much sun. Many succulents do very well in Sydney and they are standing up to the heat very well. Deirdre

  • By Anne 4280 Tuesday, 24 January 2017

    You are certainly spot on Deidre about the folly of trying to compete with the elements. Here in SE Qld. we have had less than half of our usual "wet season" rains, (so far anyway), and I seem to be continually stressed about watering and especially in the veggie garden. Have decided to not plant anything from November until February/March as it is just too hit & miss. I too have gradually moved away from the, so called, exotics and will concentrate on local tuffies.

  • By Helen 7256 Tuesday, 24 January 2017

    Its not so hot here but I still have problems if I"m not sensible. I am GUILTY of planting new acquisitions in December ( way too late really - my excuse was our cold wet spring which delayed garden bed preparations). Have managed to keep most of them alive but it makes a lot of extra work and also brain power in remembering where exactly all the newest most vulnerable plants are.

  • By Helen 7256 Tuesday, 24 January 2017

    My most successful survival story is Sedum Brilliant. I bought two tiny plants as this Sedum is reputed to stand both dry and wet and even heavy clay. The dogs found my tiny plants before I could pot them on - I found empty pots and labels the next day. Two months later found I one plant behind a hedge which had rooted itself and I planted that in the garden. Last week I found the remaining plant which had survived and layered itself and I was able to pot up 5 more sedums ! Sounds great! The herbaceous sedums don"t do well in my garden but I have some wonderful groundcover ones that thrive and are unfazed by the heat. Deirdre

  • By Richard 2112 Tuesday, 24 January 2017

    I agree with your plant choices. My sunny front garden is English Roses, salvias. bearded iris, coreopsis, ,purple fountain grass, various South African bulbs, alstroemerias, african daisies (osteospermum, arctotis, euryops), windflowers, etc, and I usually do not water once established. In the shadier back, lots of camelias (tough as boots once established), gingers, ctenanthe, palms, clivia, hydrangeas and much more! I water each bed deeply about once a fortnight at this time of year....You are good with your watering; I feel I am almost overwatering at the moment for fear of losing plants and it probably isn"t good (let alone what the water bill is going to be next time). Deirdre

  • By Richard 2112 Tuesday, 24 January 2017

    ... The many many pots & cuttings - I struggle to throw prunings in the green bin! - are the greatest challenge, however if I water before work and again in the evening they survive. I too have a long suffering friend who waters in my absence, which has been very often in the last 3 months as I have been working away a lot (& can"t trust the kids or wife to water!!) - my neighbour said to me "I see you have a gardener now"!! I find mulch and granular soil wetter invaluable at this time of year. Great to have a good friend who will water! The soil wetter stuff is something I need to use more of in future. Deirdre

  • By virginia 2125 Wednesday, 01 February 2017

    Hi Deidrre,Like you I have decided I must review what I plant. All my begonias have survived and I have 2 ixora bushes which cope well with the heat. Also interestingly a dichroa has done well and is covered in flowers but it is in shade most of the day.The acanthacae are also thriving and plectranthus in the shade. Good to hear what is doing well in your garden. I agree Dichroa is a good one. I"m interested you have had success with Ixora, which always sulk in my garden! I might need to give them another try! The plectranthus are great, aren"t they! Deirdre

  • By Angus 2750 Tuesday, 21 February 2017

    Experiencing 45 degree days the last couple of weeks in Sydney"s west. Great survivors are the Hibiscus Rosa-Sinensis hedge facing due west. Other survivors are Abutilon, Polygala, Bougainvillea, Clianthus, Justicia, Pachystachys, Cane Begonias, Cupheas, Calliandras, Iochromas, Plumbago, Crepe Myrtles and of course Pelargoniums. The Brugmansias look like wilted lettuce in the heat but pick themselves up with a drink.I"ve given up on the vege garden - too much effort and water for no crops.

  • By 10dril 3146 Monday, 20 March 2017

    Also guilty, guilty, guilty... -English cottagey things that don"t thrive - a mistake from past years i"ve been rectifying -New plants summer - also a past mistake -Too many pots - my current scourge, exacerbated by -Feeling sorry for prunings and so propagating instead of composting! Watering takes ages and the smallest plants in the smallest pots suffer. I"m just glad I"m not the only one. Re: mulch. Mandatory. + 1/10 wee/water on citrus trees. Extra N needed as mulch breaks down.

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