Black nursery pots - how to protect trees from overheat?

[funlul]

I have run out of ground space long time ago, and some trees will settle in 15 or 25 gallon nursery pots, sobs. However, all nursery pots are in black and they tend to heat up badly when weather hits 90+F.

Is there anything I could do to avoid damage? I cannot mulch since these pots will likely sit on concrete (sad!!!). Anyone has experience with painting the pots to a different color (maybe green? I have a few pots from Monrovia Nursery in green) Or wrapping them up with light color material? Or provide shading on ground level? Will these help? Also since trees stay in those pots long term, any suggestions to make them last longer?

Much appreciated!!

[buddyguygreen]

burlap wrap works great

[DimplesLee]

Is coarse Coco chips cheap where you are at? Coarse wood chips as an alternative? I find it helps to lay a foot of wood or coco chips on top of the concrete first - like mulch the concrete over then lay the pots on top. The mulch will catch any water that will seep out of the pots and keep the bottoms a bit cooler than if put on top of plain concrete. Can look ugly as heck but it works at least. Or expensive option - metal plant stands or ceramic pot feet to keep em pots off the cement. I still put "mulch" tho damn aesthetics I'd rather keep my my darlings alive and happy.

You can probably keep the path clear of mulch or if people will mind, keep the plants to the side and buy those cutesy kitcshy little plant bed borders to keep the mulch contained in the spot under and a few inches around the pots.

[greenman62]

ive painted many of my black containers white.
on really hot days i spray water on the leaves and containers

i have been thinking about covers made of cloth or something
just worried they will fall apart in the sun

i do often plant in oversized containers, and add an inch of mulch at the top.
more soil means longer time to heat up in the sun.

ive had small containers literally "cook" the roots on some plants
larger containers dont have that problem.

another reason to address the issue is soil microbes.
many of the beneficial microbes onl;y survive (or thrive)
in a certain temp range.
keeping those containers from high temp swings can make a big difference
in the health of the plant.

[BahamaDan]

Is there a special paint one has to use when painting the containers?

[funlul]

Excellent ideas, thank you everyone.
Maybe I could use 2x4 studs to build little enclosures and place wood chip / mulch inside so it's less messy.
Between paint and burlap, which one will last longer? Is white the best choice for paint?

[starch]

Is there a special paint one has to use when painting the containers?

I have been using the Rustoleum spray paint for Plastic - white. Works great.

[funlul]

Is there a special paint one has to use when painting the containers?

I have leftover standard interior paint, wonder if that would last?

[Tropheus76]

As many potted plants and such as I have, it never even occurred to me the sun might heat up the pots. Hmmm Most of mine are on the ground and the smaller ones are on a shelf. Guess I will have to keep that in mind this summer. Painting them white and having mulch on top should alleviate most of the heat I would think, that and having them so close together the pots shade each other. That and watering them often, mine get watered three times a week on auto.

[funlul]

I am deeply puzzled why are these nursery pots made black to start with? $$$ reasons?

[DimplesLee]

Maybe so it warms up pretty well during early spring but in Au and even here in the Phils I've seen green nursery pots become popular. I even have mint green, purple and pink  50 gal pots just bought yesterday - I believe the coloured pots trend started in Malaysia and spread to Thailand, Singapore, Philippines.

Has anyone ever tried that roofing paint with ceramic thingy? It comes in white only supposedly used in the tropics to keep roofs (and attic spaces) a few degrees lower (aside from really good insulation). Was thinking if it would cling to plastic then I'll paint all my black pots with it?

[fyliu]

I am deeply puzzled why are these nursery pots made black to start with? $$$ reasons?

UV resistance. White plastic tends to fall apart fast. White paint is just and extra step to do.
Heat is good for plant root to grow, unless you keep plants in them too long.

[funlul]

UV resistance. White plastic tends to fall apart fast. White paint is just and extra step to do.
Heat is good for plant root to grow, unless you keep plants in them too long.

Great, thanks!! Well, that means I need not to bother painting the 1 gallon and 5 gallons, right? Right?

I intend to keep some trees in 15 / 25 gal pots indefinitely. Would you recommend painting them?
I also wonder what is to do when the pots eventually start to decay? Lift it up and put into another pot directly? Roll eyes...

[fyliu]

I'm not very experienced with keeping things in pots. Nurseries and other people can grow big things in small pots. My plants tend to just shrink in the pots, not even trying to grow outside the circle of the pots. root pruning pots work better for me.

[Doglips]

Green is a bad color if you want cool.  Go White.  Shade the pot, a well placed 57 chevy works.  Or cool the pot, burlap and drip lines would work well in dry So Cal (burlap would also act as a weak radiant barrier if loosely attached).

[Mark in Texas]

Root pruning system pots (like fabric), white paint.

[NewGen]

For long term growing in pots, it's been proven that you can paint the inside surface of the container with copper. This promotes vigorous root branching and minimize root circling.

[greenman62]

Is there a special paint one has to use when painting the containers?

I have been using the Rustoleum spray paint for Plastic - white. Works great.

i had a cheap spray can of white.
its lasted over a year now and its just starting to chip off.
i think cleaning it makes a big difference... maybe with alcohol.

Rustoleum is a great idea. its made to stick to anything.
most primers would probably do well also.
try Kilz maybe...


as far as root - pruning
i use a small sharp knife and cut slots in my garden pots
seems to work

[Jsvand5]

I've wrapped in heavy duty tin foil before and taped it on with foil tape. Works really well.

[Don]

Hey, all my plants are in black nursery bots from megatubes right up to a coupl of 30 litre pots and all mine are on concrete that gets sun from 7in morning till 5in the arvy. Growing eugenias mostly plus jabos and some guavas. It gets hot at 35-40 deg Celsius and all mine do relatively well. Lucerne mulch thick on top and water when they need it. In these temps they need watering every 3 days odd but most times when it cools to around 30 they get it every 5 days. They also have tin fence reflecting the heat at them also so they cop it from every angle. Only plants that don't like it are e. involucrata where foliage burn happens if plant isn't watered everyday  but everything will aclimatize to it and whenever I repot, the roots are against the side of the pot and healthy as. My backyard is like a concrete desert, haha so it doesn't phase them much leaving pots black.

[funlul]

Lots of great tips floating around, thanks!!

- foil wrap
- inside copper painting
- cutting slots for root pruning

are these applied for larger or smaller pots? 

[Mark in Texas]

For long term growing in pots, it's been proven that you can paint the inside surface of the container with copper. This promotes vigorous root branching and minimize root circling.

Yes it has.    http://tropicalfruitforum.com/index.php?topic=7511.0

[luak]

I found these pots at a local nursery,they were free for the taking.I do not know what the product was,it is about 20 gls or so,it is heavy material. I drilled some holes towards the bottom.