when do you water? morning or night? poll and discussion!

[Bretts]

Ah I get 4 selections.

[Kunzea]

Hi All
Great thread this one. I read from this that from the perspective of most trees, it doesn't make much difference the time of day they get water as long as they get it when they need it. So we bonsaiists can choose to water when we are able as long as that matches the basic needs of the trees.

I disagree with Pup a little on a couple points. Trees don't get water mostly from their leaves. Most water comes from via the roots. Some water can be taken up via the leaves, but remember that the leaves are constructed to transmit water out, not in, and in the form of vapour not liquid, while for the roots it is just the opposite. Keep the humidity up around the leaves all you like, but if the roots go dry, you are likely to end up with a dead plant. Some plant propagators use fogging systems to great effect. This limits water loss from leaves of cuttings without stressing them with dry air. With virtually 100% relative humidity inside and outside the leaf, there is no or little net loss of water from the leaves, so no stress. It works with many species, but not all (eg those with very hairy leaves are prone to fungal rot in the high humidity). Also, misting occassionally doesn't really do much for the water status of your trees. Raising the relative humidity around the leaves will cause the pores to open and make it possible for more water to be lost compared to the situation with the pores closed. You might feel better, but the trees may wonder why you are doing it!

If you have a day when the soil of your bonsai dries out because of high temps, but especially if it has been windy, you are doing your plants a favour if you water them in the evening. At that time they could use a drink. They will rehydrate all their tissues over night and be ready for another hot/windy day on the morrow. If you leave them dry overnight, they may survive, but they will have survived a very extended thirsty period and have a shorter time to rehydrate than if you'd given water earlier.

Since most bonsaiists use soils that are 'free draining', it is very unlikely that you will have a plant standing in water overnight just because you watered it in the evening. You can leave a plant in bucket of water overnight and it won't be harmed in general. If you soil drains at all reasonably, a regular watering at night just won't be a water logging issue.

I'm impressed with the diversity of fertilising models people have given. It seems that the plants are happy with anything that is given regularly and in reasonable amounts, as long as your water system allows periodic through-flow of water. I say the latter because of an interesting experience I had a few years back during a particularly severe dry period. I had put Osmocote into the soil mix of some plants. I was able to do my watering with only drippers. Water didn't always drain out of the pots, but nutrients were leached out of the osmocote spheres. These salts moved through the soil and 'up' to the surface of the soil where they accumulated as a small salt crust that killed my mosses. Once I realised what was happening and gave them a thorough watering that washed the excess salts out of the, the problem went away.

My fertilising is like a number of others in this thread: alternation of a fish fert/seaweed fert/ occassionally seasol. I used to use Thrive, but don't now for no reason that it didn't work. Once I started a fairly regular program of fertilising 2-3 weekly, mostly over the growing season, and occassionally using a high potassium fert in autumn, I've improved my flowering on bonsai greatly. (wry smile - haven't worked out how to use those fangled smilies on the side!).

Kunzea

[Bretts]

If you have a day when the soil of your bonsai dries out because of high temps, but especially if it has been windy, you are doing your plants a favour if you water them in the evening. At that time they could use a drink. They will rehydrate all their tissues over night and be ready for another hot/windy day on the morrow. If you leave them dry overnight, they may survive, but they will have survived a very extended thirsty period and have a shorter time to rehydrate than if you'd given water earlier.

Since most bonsaiists use soils that are 'free draining', it is very unlikely that you will have a plant standing in water overnight just because you watered it in the evening. You can leave a plant in bucket of water overnight and it won't be harmed in general. If you soil drains at all reasonably, a regular watering at night just won't be a water logging issue.

I agree a healthy tree and soil will have little issue with being watered at night. Alot of this comes down to habit though as well as the health of the tree and soil. I aim to not water in the evening. If I think a tree will need water it gets it in the afternoon.
There is a graph some where on the net of the optimum water content to air that a soil needs for optimum health of trees/plants. Many soils when first watered will be above this optimum range. I figure the slowest time for it to get back to the optimum range is through the night.
Water the trees in the morning and aim for the tree to go into the night with enough moisture to stay in this optimum zone will allow it to regenerate after a hot day most efficiently. From memory it is about 50%-25% moisture content.
Hence I do believe it better not to water in the evening!
It is very uncommon for a tree to need water in the evening with my habits. In summer heat I will often Water everything in the morning without checking except for trees that I know are not going through alot of water and need better regulation.
Then the last water by about 3pm for anything that is looking like it will need more by the end of the day I can be confident that the tree is heading into the night with all it needs to recoup. Off course I often check to make sure that a tree is actually using the water I gave it and some may be missed from the morning water the next day.

A good point to make with this is it seems many 100% inorganic soils will almost immediately head to this optimum range and stay there for longer periods. That is what I aim for with my soils anyway.

[Jamie]

wow, i am amazed at how many response this has got, i wasnt to sure on the reaction but it seems to be a big issue.

stymie- im not sure how itense your sunlight gets over there but here in queensland where it can get to a point that water will act as a magnifier it can cause burning on soft leafed species like maples, i have even had it on elms before to.

pup- my trees have never been inside because of heat nor rain, the only time i moved them was with a cyclone threat and even then it was to a shed. if i get rain here i am thankful, we are up to about 4 months with a decent drop, i think we have had maybe 3 mm in that time

as for windy conditions this can be a major problem for me, i find i need a lot of protection from the wind for my trees as this can be a major factor whether my trees soil stays moist or dries out.
even with me watering in the evening/afternoon i have never had a fungal problem. i dont have anything that can say why or give reason to this with my climate hardly ever dropping below 20 at night, (occasionally we do get cold snaps where it can drop to 5-10 degrees).

i need to make sure my trees have enough water to get them through the days aswell, but with watering at night it allows them to stay in a moist state through the day, i think my humidity in my climate helps with this, even with drying winds.\

i have had pretty good success with this and my fert program so i dont see any reason to change it.
weekends are the only time my trees will get an extra water if needed and thats only if i think necessary.

kunzea- i dont think pup was stating trees get water mostly from their leaves, i think he was talking bout mountain species of conifer that would be readily accepting of a misting at night because this is what would happen in their environment in the mountains, as it cools down more moisture in the air will surround the trees and thus some moisture would be taken in by the foliage.

i do agree that the root system is the major water and nutrient source, i dont think any one who has so9me knowledge of tree or plant life would argue this.

i look forward to reading more

jamie

[Bretts]

I still have an open book on the water on the leaves during a hot day issue. Many of my trees get water on the leaves during the day with no ill affects on days over 40 deg.
I have heard an adaption of this which is that it is the salt buildup on the tips of the leaves that actually cause the issue. This would have alot to do with water quality though and I do try not to get them wet everyday and try to avoid it on occasions but I have never had a leaf burn from having water on it?

Leong has a picture of a fig leaf in his book that he believes was burnt by water. He called it water burn.

[Jordy]

in Tassie, thanx to our lovely whole in the ozone layer. i can say for a fact that we get water burn.
I foolishly watered my cotoneaster around 12 midday on a sunny day once...
I spent the next day picking off my damaged leaves...

[Pup]

Kunzea where did I say leaves take it in?. I said the trees get moisture from the evening mist in the mountains. Wet leaves in high humidity can lead to fungus..

Just go over to the smilies with your cursor an clik on the one you want.Like this

Cheers Pup

[Jamie]

Kunzea where did I say leaves take it in?. I said the trees get moisture from the evening mist in the mountains. Wet leaves in high humidity can lead to fungus..

Just go over to the smilies with your cursor an clik on the one you want.Like this

Cheers Pup

i was wondering how long it would take


jamie

[Pup]

Kunzea where did I say leaves take it in?. I said the trees get moisture from the evening mist in the mountains. Wet leaves in high humidity can lead to fungus..

Just go over to the smilies with your cursor an clik on the one you want.Like this

Cheers Pup

i was wondering how long it would take


jamie

I have been at one of my great grandies 1st birthday so have not been home long.
It also shows how wrong we can be. Queensland hot and humid!! not dry

[Jamie]

yea we get hot and humid, but a major factor can be our drying winds that we get, coming of the ocean from the east isnt so bad, but when it comes in from your way pup man it is dry, hot and damn uncomfortable, no offence obviously.
the wind when it comes across the deserts especially a north westerly man dries this place out something fierce.
it is the usual wind we get this time of the year, it doesnt last for to long though, it has started to settle down a lot now so i am happy with that

just waiting for the rains to get here and i will be even happier, summer time thunderstorms and rain, amazing shows.


jamie

[Greth]

I prefer evening watering because a tree can only grow when its pores are open, so this gives them the maximum amount of time during 24 hours when they will be well supplied with water.

Kunzea- watering enough to soak the pot is not enough. Generally you should aim at putting in 10% more water than the holding capacity of the container/soil. Water must drain through to avoid salt buildup. This is even more important when you are using water of high salinity (eg Adelaide water) My rainwater is relatively harmless, just wish there was more of it!

[stymie]

Hey 10C isn't cold but perhaps -10C is a bit chilly. You should try being in a strong wind at that temp. Believe it or not, I don't use a rose on my watering cans, its too slow. The medium doesn't get clumped because I'm completely inorganic in that quarter. The water flows straight through unhindered.

[Jamie]

Hey 10C isn't cold but perhaps -10C is a bit chilly. You should try being in a strong wind at that temp. Believe it or not, I don't use a rose on my watering cans, its too slow. The medium doesn't get clumped because I'm completely inorganic in that quarter. The water flows straight through unhindered.

that is the big difference between our climates mate i hardly ever drop belop !0c where you can get to -10c. i wouldnt think you would water at that temp, wouldnt you get icicles as soon as the water comes out...

the thing is compared to where i am in QLD where my temps rarely get to that compared to say country VIC where it is quite possible for the temps to get to freezing or below makes it such a vaste difference, that is why i asked the question about watering and how much, it is good for all of us to understand the watering needs of our trees, where mine will be completly different to someone in VIc which will be completely different again to someone like pup in WA.

I prefer evening watering because a tree can only grow when its pores are open, so this gives them the maximum amount of time during 24 hours when they will be well supplied with water.

Kunzea- watering enough to soak the pot is not enough. Generally you should aim at putting in 10% more water than the holding capacity of the container/soil. Water must drain through to avoid salt buildup. This is even more important when you are using water of high salinity (eg Adelaide water) My rainwater is relatively harmless, just wish there was more of it!

so greth what you are saying is if you water at night it gives the tree a maximum amount of time to soak up water? and then during the day it will use that energy from the water and grow?

and i agree with the fact you need to get a flow of water through the soils/medium as you have stated it flushes out salts but it also allows a fresh supply of air for the roots to take in aswell this is an important factor, having oxygen in the soil not only helps the tree but also allows it to breath and will help with stopping things like root rot.


jamie

[Greth]

Yes, the general point is that in hottish weather the pores are likely to be shut for much of the day, without gas exchange the plant is not actively growing or doing very much at all, it is having a siesta. It can respire and use stored starch from photosynthesis for further growing at night.

I paid a lot of attention to the 'pot watering' lectures in university Horticulture intending as I was (and am) to work up to a noticeable income growing herbs.
Bonsai of course, break the rules, noone would expect a plant to grow and thrive with such a small root space. Well, maybe not break, the idea of using a 'high gravel mix' and then loads of water and liquid fertiliser is very similar to the ideas of hydroponics (soilless gardening)..
A question arising now that I have thought about it a bit. Some hydroponic production is done by creating a lined outdoor bed filled with the gravel, so that large plants can be grown in outdoor conditions. Would this work for 'grow-beds' for bonsai, has anyone tried anything like this?

[Ash]

I have chosen to respond in the form of a badly written ballad:

The leafy end of things:
H2O + CO2 + light (via photosynthesis) = storable energy
This happens in the day
It happens in the leaves
Storable energy + 02 (via respiration) = usable energy
This happens day and night
It happens in the leaves
and the stems
and the roots
H20 is smaller than C02 and even O2
H20 can diffuse through any pore that CO2 can or O2 can
The insides of plant cells are wet
The outside air is dry
There is more O2 and CO2 in the air than there is H2O
Therefore water diffuses out of any plant cells exposed into air
And it does so day and night
But it is hotter in the day and the stomata are open wider
More water is lost in the day
Than is lost in the night

The rooty end of things:
Good soil is hypotonic (more water less solutes)
Good root tip cells are hypertonic (less water more solutes)
Water diffuses from a hypotonic to a hypertonic solution
This happens day and night
Plants do not have a pump
Their water is drawn from roots to shoots by capillarity
Capillarity is greatest when plants are loosing water from shoots
This happens day and night
More water is lost in the day than water is lost in the night
More water is moved in the day
Than is moved at night

The bad bonsai grower:
But sometimes the soil is not hypotonic
The bonsai grower failed to provide water in the day
There is not more water than solutes!
The root tips can't get water
The shoot tips still loose water
There is not enough water to loose
The plant closes its stomata to prevent loosing water
But now it cannot get CO2!
Its photosystems starve!
But still they are charged by light!
Where does the energy go?
It burns, it burns it burns
The photosystems are destroyed.

The good bonsai grower:
The soil was moist in the day, the grower kept them so
The systems were well fed with CO2 and H2O
The plant grew and grew and its trunk grew thick
All parts had air at night and so they to could respire
But moisture still they lost so the grower kept them not dry
And the grower brought in the tree to enjoy for a time
An could do so again next week, next year, in may decades time
Because it was kept moist in the day and had some air at night