The hydrangea blues

I thought as much ... the "blue" hydrangeas I planted recently are just completely normal hydrangeas which turn pink in alkaline soils, or turn blue in acid soils. Mine are a lilac colour, which isn't what I want, and so here's the story of giving my lilac hydrangeas a case of the hydrangea blues. It isn't rocket science, but it is science.

See what I mean? Those large flower petals are the originals. They're not a deep enough colour to be truly purple, they're a bit further along the colour wheel towards the pink end of the spectrum. And so that means my soil pH in this spot is probably somewhere about 5.5 to 6. The next lot of baby buds coming through are looking a lot bluer, though.

Normally, my garden soil is more down the acid end of the spectrum, somewhere about pH 5, and that should produce nice blue hydrangeas. However, the soil in this part of the garden is about 50 per cent homemade compost, and I guess that's why its pH is a bit higher (my guess is something closer to pH 6). 

None of this is a problem, of course. In fact it's just another excuse for some good gardening fun. After much Googling and reading, I realised there are two ways you can go about turning your hydrangeas blue.

Option A is to change the soil pH itself on a semi-permanent basis, using either sulphur powder or liquid sulphur. (And it is also spelled "sulfur" on some product labels, which apparently is how the scientific community has agreed it should be spelled). This is slower acting than option B, but is a more long-lasting, possibly permanent, solution as it changes your soil's pH. It's often used by gardeners growing acid-loving plants such as azaleas, camellias and blueberries.

Option B is to apply a "hydrangea blueing" mixture (liquid or powder) which is made from aluminium sulphate. This is faster acting, but it needs to be reapplied every month or so to keep the hydrangeas nice and blue. I didn't like the sound of that, so I was "yeah, nah" to this method.

This is what our local Mitre 10 store had in stock, so I bought it and applied it to the soil around each plant, then watered it in. The pack comes with a spoon and a guide to how much to use. I've taken a cautious approach and applied half a dose to each plant, and I am sure it is already affecting the flower colour a bit. If it's not that effective, I'll add a bit more later on.

This is the alternative "Option B" product, the aluminium sulfate "blueing" mixture. I didn't buy this and don't intend to, but lots of people prefer a quick fix to a slow fix, and so if you want to turn your pink hydrangeas blue within a few weeks, get some aluminium sulfate.

Finally, in case you're wondering, you can't change the colour of white hydrangeas. In the same soil that's turning my blue hydrangeas into a lilac haze, Pammy's white hydrangeas are looking splendidly healthy, handsome and dazzlingly white.

Those white flowers on a backdrop of deep green leaves really do look nice. This plant is still, of course, a baby, but the plant label says once it is is mature it will be 1.2 metres (4 feet) tall and wide, which is something I am looking forward to enjoying for many years to come.

Making the bed

So much work and so little to show for it, but that's making the bed for you. Garden beds, I mean. It's a classic piece of 'behind the scenes' work, much the same as all the scraping and sanding that precedes a decent paint job.

My garden is so small that I need to do things in a certain order, due to a lack of space. Today was 'prepare the beds where the gardenias will go' day. This is the bed I showed in my previous post, where the mother-in-law tongues once lived. Over the 22 years I've been gardening here this poor bed has hosted a range of different, grumbly and troublesome grevilleas; a totally out-of-control monster rosemary bush; and the potted curry tree, plus various others. 

The last time I tested the soil pH there was when I moved in 22 years ago, and it was mildly alkaline (7.5) back then. 

What a difference 22 years makes: now
it's acid, pH 6. Glad I checked!

It took three hours of hard yakka to
get the bed right. I made the mistake at
some stage of thinking a pebbly mulch
would look nice, and over the years the
pebbles had worked their way down
deep into the soil. There were far too
many of them, so out they came, one
by one. Then I added three bags of
cow manure, and numerous handfuls
of lime, to help correct the pH level.
Dug over, raked over, watered well,
it now has a week or two to settle in.

One good bit of news is that I scored a
nice plant this morning. I went down to the
local Marrickville organic vegetable market
(on Addison Road, Sundays 8.30 to 3), which
is well worth a visit. As well as all the fruit
and veg and other foods on offer, it also hosts
all sorts of people with stuff to sell, including
some very good little plant stands. I ordered my
Tiger grass from one plant stand and on the way
out spotted another one selling orchids, clivias,
bromeliads and lots more. The orange clivias
are the common ones, and don't cost so much,
but the other colours, such as the yellows and
reds, usually come with a hefty price tag.
$30 isn't a super bargain but it's a good price
and the plant looks very healthy indeed.

I hope that Radox stuff works its magic on my poor old back. At some stage today I used every heavy-duty garden tool in the shed: mattock, spade, fork, rake and gave my back quite a workout. Combined with yesterday's heavy lifting of all those bags, I am waiting to see what tomorrow brings when I attempt to get out of bed in the morning!