Plant sun exposure

[Link link 2]

Hello. I grow my plants on my roof and since it is summer, most of my roof is in direct light for most of the day. I am currently shielding them with shade cloths from 12-5pm to protect them from the intense heat but will I keep having to do this when it gets cloudy or will the clouds be sufficient shade? By the way is it ok to put the cloth directly on the plants or should I keep it elevated?

 

[Vicky]

Hi Link link 2, fascinating idea of growing plants on the roof (of a house??), is it a tiled roof or a corrugated iron roof? If you are covering with shade cloth, it is always recommended to have it off the plants to allow airflow and also because it will weigh them down and potentially break branches/leaves. I'd have thought that the heat coming off a roof would be quite strong, are you just putting pots on the roof? In the summer, even with clouds the uv light can damage plants quickly so I'd be hesitant to take away the shade cloth. Mind you, here in South Australia, we get intense heat and not too much humidity so I cover everything I can in summer, even those plants that supposedly like 'full sun' or they get burned to a crisp, especially with our hot northerly winds. Do you have pictures you could upload? it sounds very interesting

 

[Link link 2]

Hi Link link 2, fascinating idea of growing plants on the roof (of a house??), is it a tiled roof or a corrugated iron roof? If you are covering with shade cloth, it is always recommended to have it off the plants to allow airflow and also because it will weigh them down and potentially break branches/leaves. I'd have thought that the heat coming off a roof would be quite strong, are you just putting pots on the roof? In the summer, even with clouds the uv light can damage plants quickly so I'd be hesitant to take away the shade cloth. Mind you, here in South Australia, we get intense heat and not too much humidity so I cover everything I can in summer, even those plants that supposedly like 'full sun' or they get burned to a crisp, especially with our hot northerly winds. Do you have pictures you could upload? it sounds very interesting

Thanks for the info! We have our wash room on the 2nd floor of our house and a door that leads out to a sort of garden, over here we mainly have flat roofs not tiled roofs or sloped roofs and many roofs here have doors that connect them inside, we have some shade as well on our roof. Sorry I cannot send a picture (The file is too big) but to see just type "Maltese roofs" on google, you will not find one that looks like mine but they all have the same concept. It is pretty warm on the roof (Actually we have been having slightly cooler temperatures recently thankfully) but the reason I am not using our back garden is because there are tall buildings around it so it only gets direct sun from 12-3, which is the time I want to cover them. The roof gets direct sun from 8am to 7pm so I can give plants morning sun and shade them for noon and the afternoon sun (The roof also has much more space). Also here it is typically very humid. Thanks again for the information Vicky! Good day!

 

[ClissAT]

Link, it's really important to have cool roots for your plants. I assume they are in pots or some sort of container?
If so there might be radiant heat coming up from the floor they are sitting on.
I have previously used old styro boxes (white foam fruit or vegetable boxes from the market.)
Cut the boxes down into wide flat sections of sides and bottoms and place under the containers.
That will go a long way to helping the plants get through each day.
Cool roots work much better to provide moisture to the leaves to prevent sunburn.
If their leaves shade the top of the growing medium, and that medium is cool to the touch then your plants might be ok once the medium is cool from top to bottom.
The growing medium needs to be cool so the roots don't get overheated. It will also help with moisture retention to have a cool root run.
If the plants are normally ok in full sun, then giving them cool roots should be enough to help them get through your summer months.
But if your plants usually prefer dappled shade or part shade or are understory plants then yes they need light shade cloth over them.
You can erect it permanently so you don't have to babysit your plants every day.

 

[spector]

This is part of the rooftop garden on top of Levi Stadium in Santa Clara, California. I am so jealous!! Of course, even if my roof were flat enough for a garden (which is is definitely NOT), that much soil would cause it to collapse on top of me!

 

[Link link 2]

View attachment 5137

This is part of the rooftop garden on top of Levi Stadium in Santa Clara, California. I am so jealous!! Of course, even if my roof were flat enough for a garden (which is is definitely NOT), that much soil would cause it to collapse on top of me!

My roof is actually not very big and I also use containers as it might be a little too heavy to use raised beds or rows, but it is still rather flat so it works! That is not really how most our roofs look though so maybe to see a picture of something similar, type in Maltese roof tops (Malta as in the country in Europe).

 

[Link link 2]

My roof is actually not very big and I also use containers as it might be a little too heavy to use raised beds or rows, but it is still rather flat so it works!

Link, it's really important to have cool roots for your plants. I assume they are in pots or some sort of container?
If so there might be radiant heat coming up from the floor they are sitting on.
I have previously used old styro boxes (white foam fruit or vegetable boxes from the market.)
Cut the boxes down into wide flat sections of sides and bottoms and place under the containers.
That will go a long way to helping the plants get through each day.
Cool roots work much better to provide moisture to the leaves to prevent sunburn.
If their leaves shade the top of the growing medium, and that medium is cool to the touch then your plants might be ok once the medium is cool from top to bottom.
The growing medium needs to be cool so the roots don't get overheated. It will also help with moisture retention to have a cool root run.
If the plants are normally ok in full sun, then giving them cool roots should be enough to help them get through your summer months.
But if your plants usually prefer dappled shade or part shade or are understory plants then yes they need light shade cloth over them.
You can erect it permanently so you don't have to babysit your plants every day.

Ok, I will try that thank you very much!

 

[Vicky]

oh wow, I typed in Maltese roof tops as you suggested Link link 2 and came up with a picture that was awesome for gardens. Great idea you had, I could just imagine what it would look like if everyone there had a garden of sorts out on their roof! Actually, two or three of the pictures did have gardens on the roof, looked sooooo much better! Gotta start a rooftop garden movement over there hey??

 

[Link link 2]

oh wow, I typed in Maltese roof tops as you suggested Link link 2 and came up with a picture that was awesome for gardens. Great idea you had, I could just imagine what it would look like if everyone there had a garden of sorts out on their roof! Actually, two or three of the pictures did have gardens on the roof, looked sooooo much better! Gotta start a rooftop garden movement over there hey??

I will certainly try!