AusBonsai

Heya Gang,

I have put up some 50% openness green shade cloth across one side of my balcony to the other.

Would it be a bad idea to have this up always? I have all (or most) of my plants under it...I have a gut feeling it will be OK as many nurseries I have visited cover all their trees regardless of species with massive shade clothes...but I am looking for a answer from experience please....

Keep her up? Or only on hot days? Keep in mind I didn't have enough $$ to get the proper securing clips for the shade cloth so just used HEAPS of old bits of wire and did a butcher job where I secured the cloth by putting a tiny hole in it - sliding wire through and tieing it to balcony LOL ok so its probably 55% openess now lol

It is hard to give advice to other people like this. If you are getting alot of direct sun into the balcony then I would say yes it could be ok all year round even or at least just for the summer. But if your trees are already struggling for enough light in your balcony then it would be better not to have it at all maybe. But something to stop hot wind may be important.
It will all be a little about trial and error and the type of trees you have. If they are all junipers or such then the more sun the better I find.

Billa, Bonsai are tree's and need to be given full sun for health growth and short inter-nodes, I live in South East Queensland and all my tree's grow in full sun all year round the only protection in on my good tree's and that is some hail netting for the summer storms.

The only exception I think is the few species that prefer part shade and the smaller tree's Shohin and Mame that may need extra protection during the hottest days in summer.

Billa, you are in melb, although we are a southern city we do get a pretty strong sun in summer. I live in the west of melb and in summer we get strong westerly winds , combine that with a hot day and say good bye to my bonsai that are in bonsai pots. The ones in plastic nursery pots still in training are fine. I have my trees in full sun from April to mid November and up untill this year I was using a potting mix with high organic content that holds plenty of water. I put my 50% shade cloth up as soon as we get consistently above 28c days in summer and it stays up untill summer is over. I leave it up out of convenience as I am to lazy and it is too difficult to put up an take down on a regular basis. If I was you I would devise a away of installing it easily so you can put it up only when you need it.
IMO wind is far more of a threat to you soil drying out than a hot day. Every environment is different and therefore everyone will have different results and methods to keeping their trees.
This year I have change to a smaller organic matter in my potting mix due to the fact my trees realy suffered during winter because there was just too much moisture around . So come summer I may be in for a challenge to keep the water to them and may have to think of another way of dealing with the summer heat.
Hope this help.

Billa,

What trees do you grow, and are they in small pots or larger pots?

You also need to distinguish between sun protection and wind protection. Chinese Maples can go in full sun, but add drying wind and Pines can take it all. Olives can take full sun and wind, and also pretty heavy shade. At the end of the day, you need to figure out what works for you and your trees.

Cheers,

Andrew

I have permanent 70% shade cloth--angled so that in summer I get mottled sun until 10 or 11 am then shade for the rest of the day----in winter get direct sun pretty well until 3 or 4 pm--but that also means I have to shift some plants to suit each season

Full sun all the way.

Rather than shade cloth look into a misting system, you should be able to set one up for $100. Then you can have nice shallow pots, inorganic soil and the awesome growth that come with it!

I will be looking into that for sure once I move back into my own join.

Is there such thing as shade cloth in the 10-20%??? Im yet to enclose my bench to promote a micro environment for my figs but i dont wanna rob other sp. of trees of too much sunlight

I believe 50% is the lightest that is available. There was some theory a few years ago that green shadecloth was not good for plants (being green themselves???) so many commercial growers switched to other colours in shade cloth.

Shade might keep your trees alive but the long intermodes and coarse growth makes it harder to achieve good results. Much better to learn to water properly and other ways to extend moisture before resorting to shade.

I have a cover that is 50% in white colour. My shade cloth only goes up when it gets really hot, sometime in Dec and comes off at the end of Feb. I only cover part of the nursery where the sensitive plants live. Pines, juniper, tridents and zelkova are tough enough to cope with full sun all year round in my area.
Last year the display bonsai had no shade all summer with no problems.

You have all left plenty to think about

Full sun is preferable but it does depend on what you are growing, whether it is pot bound, recently re-potted and what you are growing in (soil and pots)? If you are on concrete that will add to the heat via radiating it back out, that old tv ad about the egg on the paint tin is close to the truth. 30•c + a hot northerly wind can fry your plants in a couple of hours, misting may not be an option if you are on a balcony above other residents, depending on how many plants you have you may choose to put the pots in a shallow saucer of water with a little seasol in it, be careful here not to let the plant sit in it all day or for days on end, just the right amount to last till after midday would be fine. By the time you get home you should find moist soil in the pot.

Mulch is a good idea if you can keep it off the trunk, it will regulate the temps to a point in the pot by insulating the roots, I have used 20-40mm pine bark with cow manure at 50/50 with good results. If the cow manure worries you just leave it out and if you have small pots this practice doesn't work well. Sphagnum moss is a great way to keep moisture in your pots as well and may be easier to handle than pine bark and will certainly hold more moisture.

Trial and error on weekends where you can observe the environment during the course of the day is a good way to work out what works best for you. Midday onwards is when the heat really starts belting down, if you are north, west facing or a combination of then damage is very possible, if you are east facing or south then a little protection from wind exposure would be all you need. 50% shade cloth would be as far as you need to go and rolling it up on a milder day is a good idea. It will certainly cool things down on your balcony.

Most important, take it down around mid to late march. (if you have installed it with the ability to roll up, leave it up until we start getting consistently above high 20s each day.

shibui wrote:I believe 50% is the lightest that is available. There was some theory a few years ago that green shadecloth was not good for plants (being green themselves???) so many commercial growers switched to other colours in shade cloth.

Shade might keep your trees alive but the long intermodes and coarse growth makes it harder to achieve good results. Much better to learn to water properly and other ways to extend moisture before resorting to shade.

I have a cover that is 50% in white colour. My shade cloth only goes up when it gets really hot, sometime in Dec and comes off at the end of Feb. I only cover part of the nursery where the sensitive plants live. Pines, juniper, tridents and zelkova are tough enough to cope with full sun all year round in my area.
Last year the display bonsai had no shade all summer with no problems.

Thanks for your opinion, the way my bench is situated it will receive full sun up until about 2pm and then under shade, hopefully something considerably less than 50% thruout the afternoons and into the night [by rolling down the shade cloth, enclosing the whole thing] keep the internal temps and humidity up for aerials, propagation and so forth, at least that was the plan.

Back to the drawing boards.

He VS. Maybe shadecloth is not the material you want.
Some of the greenhouse cover plastic sheet incorporates light shade. eg

Gro-Tuff Greenhouse Plastic 7.5m wide
Australian made and owned Gro-Tuff� Greenhouse film. For domestic and commercial use, use to cover and protect your vegetable or flower crops. Gauge: 150 um Light Transmission: 88.5% Light diffusion: 42%
Gro-Tuff contains the worlds best UV stabiliser, so it will consistently outlast all other greenhouse films.

or

White Spun Polypropylene 17 grams 1.6 mx 100m
Per Roll Light and tough, easy to handle, resistant to rot and fungus, non-toxic to plants, chemical resistant, UV stabilised, is easily cut - does not fray, and is easily sewn.Can be used as frost protection.
Thermal Qualities - retains heat at night. Temperatures can be increased between 2�C and 5�C.

both those from Sagehort in Melb but similar products should be available from a supplier somewhere up your way.
Greenhouse plastic will also block out any rain but very good at holding humidity and temp. 88.5% transmission should mean 11.5% shade? You may find some brands with higher shade factor. Light diffusion means plants do not get blasted with direct sun.
Polypropylene is sold as 'frost cover' and is a bit flimsy. Tends to tear and wear quite quickly but very light and easy to use. It will probably also block much of the rain.

Thank you kindly for that Shibui, Ill look into it further before summer hits because its already nearing the high 20's