Monday, December 13, 2010

Preparing for a Hot Tropical Summer

I know that Summertime in some parts of the world is a wonderful time for gardeners.  Here in my corner of Oz ... it can be a woeful time!  Located only a mere 2300 kilometres (1450 miles) from the Equator and averaging around 320 days of bright glorious sunshine every year, my garden is positioned in a hot dry spot on the planet.

Summertime can be excruciatingly hard on both the garden and the gardener.

Summer months are always hard-going with daytime temperatures that average around 31°C.  Of course the mercury can climb to 40 (104F) some days.  Unfortunately the heat is not a dry heat, it's sticky and uncomfortable as the humidity is frequently between 60% and 75%.  We don't fare any better at nigh time either as the night temperatures average around 25°C (77F) and there is little relief from the high levels of humidity, even then.

It's the humidity that makes life hard for this  gardener during a north Queensland summer.  I rarely venture out into the garden during this time of year, so the garden has to survive without the usual care and attention that I lavish it with during the Autumn to Spring.

Preparing for a torrid summer is often a useless, forlorn exercise ... especially if we get cyclones with their destructive winds and the torrential driving rain of a 'wet' season ... but it has to be done, and it begins long before summer arrives.

First, choosing plants that can withstand fierce sunshine, sweltering temperatures and driving rain is a great starting point.  Plants such as the old-fashioned Rosa-sinensis is a staple in every garden I've had here in the northern tropics of Oz.  They are among  the most resilient, hardiest plants I've every grown ...

... and I can't recommend them highly enough.  My favourites are the hybrids 'Roseflake' and 'Snowflake'.

I also couldn't do without Palms ... again, they are just such a wonderful survivor in our climate and conditions.  Top of the list is the Dypsis lutescens - the clumping Golden Cane Palm.

I could go on and on about choosing the right plants ... but that's what I cover in most of the other posts on this blog.

So let's get on with the preparations needed to survive a Summer.  Next, there's the trimming back ... this begins in early Spring so there will be lovely new young growth that will hopefully bounce back from the torrential rainfall we can receive.  I spend at least a whole weekend cutting back the bed of Acalyphas out the front of the house ... (another plant I would highly recommend) ...

... and the bed of Hibiscus rosa-sinensis, Pseudomussaenda, Russelia, Combretum and Mussaenda on the other side of the front stairs.

These beds are then given a good feed of blood and bone fertilizer that's watered in very well.  Then, after the Spring months are over, the plants are ready for the onslaught of summer.  Here's a view of them right now with all their wonderful healthy, strong, new growth.

Another vital ingredient for a well-prepared tropical garden is mulching.  This again is done before summertime so there's more chance of the mulch actually providing cover long before the extreme heat and strength of the summer sun sucks every ounce of moisture from the ground.

In the front garden beds pictured above, I use scoria ... a type of volcanic rock ... as a mulching agent.   I also use scoria on my Pentas bed.  This photo gives you a closer look at it.

Why use a non-organic mulch?  The most important reason for this is that it provides protection from termites.  Here in the northern tropics, termites are a huge problem and having organic mulches close to wooden houses is just a disaster waiting to happen!  (Speaking from previous experience!)  As these front yard garden beds are all built up close to the timber structure of our house, we don't want termites setting up home in the mulch and then moving into our house!!

Termite protection aside ... scoria has other great features as well.  Being so porous it absorbs and holds a lot of water which is then slowly released to the surrounding plants over a longer period of time.  That way every drop of precious water is used in the most productive and useful way.  It's terrific for drought proofing gardens.  It's also acts like insulation protecting the soil in these areas of our property that are open to the drying effect of the intense sunlight and the winds we experience during our summer.

In other areas of the property, I use organic mulches.  In the long driveway garden beds there's always layers of leaves that have fallen from the many tall Eucalyptus trees on either side ... and it's just a matter of using the leaf blower to pile them up under all the shrubs ... as you can see clearly in the photo below.

In the newly established beds outside my greenhouse/shadehouse garden, I scatter dried sugar cane mulch all around the plants.  It's easily obtained here in my part of the world as we're so close to cane farms, thus it's a sustainable and renewable resource.
Here's a closer look at the sugar cane mulch ...

... the best feature of this mulching agent is that it doesn't become as compact and impenetrable as other organic mulches have a habit of doing here in the tropics.  It stays rather coarse and allows not only the rain to penetrate, but also fertiliser.  I've tried other types, but would never go back to them now.

One more great feature of this mulch, is that it's perfectly suited to areas that have a lot of run-off during the heavy summer rains.  This area of my property certainly has that ... as you can see from the bare patches in the lawn in the photo below, the run off from the torrential 'wet' season rainfall can be quite damaging.
I find that the dried cane sugar mulch used in those raised garden beds really knits together well and doesn't get washed away as easily as other mulches.

Pictured above is another of the areas that suffers from heavy summer rain run-off, and it's the roots of the huge Nephrolepis biserrata - the Giant Sword Fern - that mat together and hold the soil in place as the rainwater surges down the slope.  This fern, given lots of room, makes a beautiful low maintenance protective cover for areas that can be drastically eroded away by gushing rainfall.

Finally, one of the hardest parts of my garden to look after during our Summer is definitely the potted plants.
I have well over 100 pots, containers and hanging baskets in both my courtyard garden and my greenhouse/shadehouse garden.  Potted plants can be very demanding during hot summer weather.

Now while terracotta pots do indeed look fabulous, anything planted up in a terracotta pot will lose water very quickly here through evaporation.   Most of my potted plants are in plastic pots simply because they lose water less quickly.  I also make sure that the tops of all pots are mulched.  I use mostly bark chips as you can see in this potted Alocasia.
I also ensure every pot has water-retaining vermiculite added to the potting mix to help prevent water evaporating from the soil. 

Standing pots in groups in a semi-shaded, sheltered place also reduces evaporation.  This really helps many of my potted plants to get through our summer.

Hanging baskets need more water than pots on the ground.  Most of my hanging baskets and containers are in my greenhouse/shadehouse garden which is protected by shadecloth that blocks out 70% of the harsh sunlight ....
.... and is watered by a timed watering system. You can see the black irrigation pipes snaking along the top of the supporting poles.

Of course, with both hanging planters and pots it's never a good idea to water in the intense heat of the day ... the water will simply evaporate before your very eyes.  I always water very early in the morning before the sun has risen too high or I wait until the sun goes down ... and instead of a quickie every day, I give each plant a nice, deep drink every second day.  Far more beneficial!


  1. I know the Nth Qld heat is hard on gardeners but your garden is looking like it is thriving. Mulching and chopping back are essential aren't they?
    Your area is so much hotter than ours. I still enjoy working in the garden in Summer but only before about 10 AM or after 5PM.

  2. Hi Bernie, you are certainly very well prepared for a hot summer. The pruning is like a born again for the plants. All your plants look very well and you have many to look after. Thank you for all the good hints how to make the best of the plants during summer. Most of my potted plants are in terracotta and I know in summer they are a pain! Over summer I have a rest or I do a bit of work very early in the morning.
    But, I am never as well organised as you are! For now it was just to wet and then some of the blasted weeds took over. In my ears reverberates
    "one years seeding, seven years weeding"!
    Today I have repotted some of my pond plants. My daughter gave me a giant Papyrus, it is fantastic, it needed a bigger pot as well.
    Hope summer is kind. T.

  3. Missy ... thanks for your kind comment. Yes the garden is looking pretty good as a result of the rain we received all through our supposed 'dry' season this year. Of course, it's the 'wet' season rain that does all the damage ... so fingers crossed it's not too bad this Summer.

    Titania ... that's exactly what the trimming is - plants being born again so they're strong enough to withstand whatever the Summer has to throw at them. I'm just like you, I only really pop out to the garden very briefly in the early morning ... sometimes in the evenings, but usually by then the humidity has taken its toll. I'll be looking out for a photo of that giant Papyrus ... I only have two plants in my pond ... that's one spot that needs attention in the future.

  4. I can certainly sympathize with your having to deal with hot, humid summers. Our summers are intense also, often with temps in the 90s and very high humidity. I enjoyed reading about your preparations, many of which I am familiar with. I do a lot of mulching! We sometimes have torrential rains, but that can happen any time of the year. July and August can be very dry, which creates even more problems for heat stressed plants and gardeners. I admire all of your wonderful potted plants. You do a great job taking care of them.

  5. Deb ... sounds like your conditions are similar. We really only receive torrential rain during our Summer though ... for the rest of the year, it's usually pretty dry. I've been improving in my care of the potted plants over the last year or so ... it's been a big learning curve as I haven't had as many pots as I have now.

  6. Oh i lost my comments! I said looking at your plants seem like looking home. But yours really look more healthy than ours. I can also imagine the long man-hours you spend in your garden. It is really easier there than here as your temperatures are lower than ours. No wonder our plants look smaller and stunted than yours. Our summers are also longer which killed a few of our fruit trees last summer. This time no grasses nor weeds can be seen, sometimes clayey soil even crack. And oh much more, i just envy your conditions. I can relate to the humidity because maybe it's the same though. When it is coupled with bad water system in the provinces, you dont like to garden at all, just plant the hardiest and leave them there, come rain, come sun!

  7. Andrea ... it does sound like you have it far worse. It's such a shame when it's so hard to not only establish a garden, but then to try and keep it going in such conditions only to lose plants. I've also lost so many plants over the years, especially during the drought years ... the 'dry' season can be bad, but the drought years were horrid! We're fortunate that we seem to have moved into a different weather pattern.

  8. Bernie ~ You and your gardens are an inspiration. Thank you for sharing all that loveliness that surrounds you, and for your gardening tips. It is 'cold' here for a change, and very windy. I do need to handwater some things as it's supposed to get really cold tonight.

    Have a great day ~ FlowerLady

  9. Bernie,
    It is hot and humid lately isnt it? thanks once again for sharing photos of your lovely garden. All that greenery certainly makes it LOOK nice and cool! lol. I just got some council mulch which I find works perfectly for me at this time of year. One thing you havnt mentioned about the wet season is the mosquitoes! I find that our back garden is much cooler and more pleasant than in other areas, but this year the mosquitoes seem to be so bad. Your rex begonias are so pretty - I really must get more of those :0. Happy christmas!

  10. Flowerlady, you're so sweet! Thank you for your gracious comment ... I do hope you get those plants watered before the cold sets in.

    Africanaussie ... I was wondering if you had left yet but then I found your comment. Hot and humid ... understatement! It's stinky! About the mosquitoes ... I've found that since we moved out here we haven't had half as much trouble with mozzies as when we lived in the city's suburbs. I'm not sure why ... but there seems to be far less of them out here. Of course, we still get a few during the rainy season ... but we use our Citronella candles if we want to sit outside in the evenings.

    Maybe you're getting so many because of all the rain we've been getting throughout the year. I know in my last house I used to scatter lots of sand around the garden beds to soak up all the pools of water that would be everywhere during the wet season. It seemed to work ... it looked a little unsightly for a while but the mozzies seemed to move on!

  11. What a fascinating look at the problems of gardening in such a trying climate. So different from the mid-Atlantic. states in the US. Your garden looks to be very large.

  12. Love your plants that are planted in containers. Also I like the way you displayed them... they look so nicely together. Over here, I have to water daily. Sometimes during hot sunny days, I have to water my plants twice in a day. How I wish if I could have the irrigation system like yous ;-)

  13. Oh my! I can take 104 F for the summer but not with all the humidity. Of course, when we do get rain here in Central Texas it comes with a hurricane or tropical storm - feast or famine. All that humidity/moisture does give you a beautiful place to garden. I enjoyed reading all about your treasures.

  14. You have been busy Bernie. I think it takes a very special kind of person to put as much love and attention into a garden that looks so wonderful especially in those temperatures.
    Don’t go overdoing it in that heat. A wilting gardener is no a pretty sight lol!
    Thanks for a fabulous informative blog. While I’m shut indoors later in the week and I can’t get out because of the snow. I will think of you and your heat and plan my summer beds and baskets. (All Christmas shopping done so I can think of gardening again) Thave a good week
    Sue x

  15. Pat ... my garden is larger than the usual suburban block so I'm lucky in that respect. It can be very trying keeping it all going at times, but I wouldn't be without a garden!

    Stephanie ... the plants in the standing containers have to be watered by hand but I usually water every second day and give them all a deep drink. During our Winter I water them less frequently.

    Tufa Girl ... yes heat is one thing, but heat with high humidity is quite another. It really saps your energy. Even though I've lived here quite a while, I'm still not all that comfortable with these conditions in Summer.

    G'day Sue! Kind lady, thank you for your lovely kind words. I can see you sitting down with a cuppa planning and scheming for next year ... enjoy!

  16. Your summers sound much like our summers here on the Texas Gulf Coast - hot and humid. Great post with lots of information I can put to use here. Your garden looks in great shape for the coming summer, just as ours are going to bed for the winter :-)

  17. Hi i love your flower garden. It looks nice and attracting, as i have just started my greenhouse for flowers.


I appreciate your comments and will endeavour to reply to all. All comments are moderated, so spam will be fried.

Related Posts with Thumbnails