You would need to work out the radius of the plant's dripline, then convert that to an area. Multipy this by the required mm of rain, and that would be the volume required for that plant. Obviously however, you have runoff issues, so you need to also take that into consideration. It might be easier to water the planst as best you can, and if they look like they are suffering, just water them a bit more.

I would just water the plants that are just starting to wilt or looking stressed.

Have you tried using soft drink bottles with a hole in the lid, and another small hole at the other end, to allow water to drip out over a day or so? Not feasible with all your plants but for a few special ones it might help.

It is very disheartening when it gets this dry. We have had a few showers go past but missed out on them here. At least with own our dam water, even though we have to be careful, we can still use a hose. Some of my established plants are wilting during the day but spring up when cooler so they will go a bit longer without watering. I actually saw a large established frangipani wilting badly this morning when I was out so it must be getting dry.

To try and be optimistic, I try to think that we are one day closer to rain than yesterday.

Mistymorn have you got a septic recycler or do you have trenches. Using the recycle water has been a godsend for me. We have a long hose on ours with 3 sprinkler heads so I can cover a big area using it on everything but the vegies. We were lucky and had 30mm on Wednesday night.

Hi Everyone and thanks for your ideas..Yes I will do as you say I will give them maybe 1/3 a bucket and see how that's goes and when they start looking limp in the early morn ( limping during the hot days makes it hard to tell ) I will give them more.

I am on Town Water and Sewage but I have connected one of those wide black hoses to the bath outlet years ago and all that water goes on to the plants at the side of the house so that's a bit of a help but the block is a 3/4 acre one and believe me we are not looking forward to this. A lot of the garden is 3-4 years old now and at last starting to get big enough to take care of itself, though a lot of the newly planted things cannot as yet.....Cheers...MM.

You might find it more effective, to plunge the pots in the bucket of water, wait until the bubbles stop, then take it out. Let the drips go back in the bucket.

This might conserve your water more efficiently.

it gets messy figuring it out but here goes:

figure out the drip line as Pos02 said and work from there

eg (and this can be used as a good guide:

a yard is 36 inches, so a square yard is 36X36 = 1296 square inches. if one inch of rain falls on that square yard you have 36x36x1 = 1296 cubic inches

according to the google converter 1296 cubic inches equals 44.88 american pints and 8 pints to a gallon is roughly 5 1/2 gallons per square metre

want it in metric?

a metre is 100cm so one square metre is 10000 square centimeters. an inch is approx 2.5 cm so to get the cubic measurement of 2.5 cm rain on a square metre 10000 x 2.5 =
25000 cubic centimetres or approx 25 litres to make the equivalent of 25ml of rain on each square metre

Thanks Paradsi for posting the Metric I gave Imperial Measures up decades ago marvelous how time flies
40 years have gone since it started. Thats a lot of water 3-6 buckets on a m2 I dont even water them that much
now and this is Queensland its a wonder they dont rot over the seas..

Guess I will just have to keep my eye on the newly planted ones..Many Thanks Everyone .....Cheers..MM.

I just remembered when I worked at a wholesale nursery years ago, they used to say we had to have at least 6mm-7mm of rain to stop watering. That was for pots but a little bit more would probably keep plants in the ground alive.

hi mm, I find that most plants do well on a half bucket a week in our dry summers, smaller plants I give them a bit less, but if I see things wilting I do give them a top up as well, but I mostly grow heat and drought tolerant plants that survive drying out in between so this is just a guide, youll know better from observation how your plants are doing and what theyre needs are. roses will do ok on this but they do prefer more water to get any flowers out of them.

I couldnt imagine giving anything 3-6 buckets a week, youd think theyd drown :)

Hi TG How are you, How did you know it was my roses I was talking about, that 3-6 buckets was over m2 not per plant but with roses planted a metre apart it would be a m2 and I don't want to water the whole area just the plant so I will try the 1/2 bucket a week...I don't mind if they don't flower I just want them to keep alive during these dry times, though blooms would be a bonus....Its not the volume of water so much it the work carrying the buckets as hubby and I are not getting any younger....Thank you for your Help.....Cheers..MM.

misty (and other brisbanites) you could cheat a little bit with the watering - though it needs two of you and a large funnel - -

put a large funnel into one end of your hose (near the tap) and have someone put each bucket load of water into the funnel - and have the other person at the far end of the hose directing the water where they want it to go.

You're still watering by bucket and the hose isn't hooked to the tap and its an aweful lot of messing around because our governments won't spend on infrastructure.

Up here on the Sunshine Coast we have enough spare water to supply Brisbane and surrounds and stop all of your water restrictions. But I guess it's cheaper to force water restrictions on people than it is to build pipes up to the Sunshine Coast and with restrictions in place they can even turn a profit on not building pipes and dams by fining the gardners.

And then the government wants more people to move to Queensland (it's currently more than a 1000 a day) - where will the water come from for them?

hi mm, haha, I was just trying to remember what plants you grew from your pics and then it came to me that youve posted pics of your beautiful roses before so it was a lucky guess. :)

we've been on water restrictions for about 6 years so I can really relate to what youre going through, it's really hard to get things established and I know what you mean about the buckets, it is so much work lugging them around and I have a much smaller block than you but I get really sick of it sometimes. I hope you get a good downpour soon mm

I've contacted the botanic gardens and council asking them what the water consumption rates are for the more common garden plants. Hopefully they can provide realistic figures for all of you bucket luggers in Brisbane.

When I get a reply I'll post a new thread in Oz Gardening

While I was searching I also found this site http://www.brisbane.qld.gov.au/BCC:STANDARD:399770485:pc=PC_681

where rate payers can get free plants - just another valuable resource for Brisbanites

Here is a link that might be useful: free plants brisbane

Hi Paradisi.....I will keep a eye out for that thread it should be..interesting.
On the subject of free trees for Brisbane residents hmmm how come they only get two.
Here in Logan we get three free trees every year..I usually collect mine every January.
But this year I have not bothered due to the water restrictions....
Cheers....MM.

We had 12mm of rain yesterday and by the showers we are having tonight it will be about the same today.
Are you getting any rain Misty?
So far the odd showers we have been getting has kept my garden going but I have not planted the vege garden this year. I also have 10/15 cm of chipbark mulch over most of the gardens.

Yes we got 2mm Yesterday morning ( Wednesday ) not enough to settle the dust.
Have not had any rain for about three weeks when we got two lots of 5mm....MM.

More than what we've had - only a few passing showers hardly wetting the ground. Except for a couple of light showers a couple of weeks ago, nothing since halfway through January, that was about 40mls.

We have been getting good rain. 8mm yesterday and I looked at the gauge this afternoon and we have had 20mm today with more rain since.

Had a little more rain Thursday to Friday morning 4.5mm.
Its keeping the grass green but cannot get through the thick mulch.
Cheers..MM.

An easier may to work out volume. This formula breaks every thing down to its common denominator.

Work out your square area in metres and then multiply the depth in millimetres. The answer is in litres.
Why use the complicated imperial system when in many cases you can do the above in your head.

Here is an example:
You have a container 1 metre square. this is 1 square metre.

The depth is 1000mm (or 1 metre).

1sq metre x 1000mm = 1000 litres. Or put another way 1 cubic metre of water = 1000 litres. (and I didn't need a calculator).

Doug.

Thank you very much Doug..I only want to water certain plants not a whole area.
I needed to know how many buckets of water I would have to fill and carry
To keep my Rose plants alive so have decided on 1/3 to 1/2 bucket a plant till they droop.
But due to that beautiful rain last week we are still allowed to water with the hose.
Cheers..MM.

Misty,

There are a lot of variables when calculating how much water for a plant. If you water deeply and less often the roots tend to be deeper down in the soil and do not dry out as much. You can train plants to do this by watering less often but more deeply. If you have roses drooping, keep letting them droop for a bit longer before you water and their roots will adjust.

Travelling around the grape growing areas of South Australia and parts of NSW one can see healthy roses blooming at the ends of the rows. They are only watered when it rains or when they have to irrigate. They enjoy the same conditions as the grapes which can be pretty dry at times and yet they thrive.

If we molly-coddle our plants too much they get all soft and spoiled (just like humans).

Do you guys use soilwetters such as Wettasoil on your plants? They need much less water as what you give them soaks in really well, rather than running off. The liquid stuff's best, although messier using a watering can, than the granules, which I don't care for much. Alternatively, buy the spray on bottle and do everything at once !

Robert,
I once heard the roses are planted as an indicator of a fungal attack on the grapes. The rose is more suseptible thus giving an early warning.
Do you know if there is any truth in this?

Doug.

I believe roses used are used as an indicator for black spot and powdery mildew. They are supposed to be more prone to the diseases. However in the bigger vineyards, these days more scientific methods are used for timing spraying for fungal attacks. They measure temperatures, humidity, rainfall, etc. If it is dry then the chances for infection are minimised and spraying is cut back. Black spot tends to be spread by rain droplets.

Because there was always a tradition of planting roses with grapes, a lot of vineyards now tend to have rose just for decoration.