air conditioning would be the only way in that kind of climate - is there a cooler season at all?

If the residence is cooled with aircon - maybe grow them in there - but I wouldn't think it was worth it frankly.

Yeah, the soil temperature is going to be the biggest thing here. Shade cloths, white mulch, anything you can do to keep the sun off the ground around the plants will help.

Since Sri Lanka is so close to the equater, I'm assuming you don't get real "winter" there, but if there is a cooler season, that would be the time to plant those crops, help them out as much as you can.

On the flip side, you could always change it up and plant more tropical styles of fruits and veggies that would do better in the climate you have. Kiwanos and Dragonfruit would probably love the conditions out there. So would most peppers. Miracle Berry could be interesting as well.

Going to have a hard time with broccoli, potatoes, etc though.

Day length is an issue, too. We've had discussions about various crops, including soy and corn, that do strange things if grown outside of the latitude they evolved in. I know I tried Peruvian Purple corn and Teosinte here just to play with them, and as promised, neither of these would tassle until around/after the Autumn Equinox when short days returned, and of course that was too late for a crop. Same with Oca, which won't begin to form tubers under long-day conditions.

Why not grow appropriate hot-climate crops that serve a similar purpose instead trying to achieve the impossible?

Okay, its just my engineering background showing up here as spitballing, but...

What if you mounded up the garden so that you could put metal pipes through it all? Have a glorified funnel at the top end you could poor water through, and have the pipes come out on the low end into a catch basin to collect the water? Basically build a water cooling system.

If you had access to a natural source of flowing water nearby anyway, you could channel some of it into the pipes and then let it go back into the normal flow after it went through your garden pipes.

Probably way more work than it would be worth just to grow some potatoes though.

The problem here is that we're talking about different kinds of 'cool'. I've lived in similar parts of the world, where the groundwater temperature comes out at 26-28 C (79-82 F), which is way too warm for any cool season crop even if your system worked with 100% efficiency. Same goes for mulching - the soil will never get cooler than 26 C and even that is much too warm. An evaporatively cooled greenhouse might work in a very dry climate but not Sri Lanka, so air conditioning is probably the only way. However, you could grow heat-tolerant vegetables as someone suggested. Replace broccoli with collard greens. Replace spinach with amaranth and sweet potato greens. As for lettuce, no loss there ;)

Yup, I agree, don't try to reinvent the wheel. Work with what is available and what grows well there. I would ask around at local markets and see what the local farmers grow. They may be able to offer sources and suggestions.

Your best option (unless money isn't an option) would be to grow "micro-greens" or sprouts of your favorite cool season veggies.

This would only really add flavoring to sandwiches, soups, and salads, though...and it would require a good amount of bulk seed. Still, it's the easiest way to get those flavors in a fresh way.

Also, Swiss Chard is somewhat heat tolerant...a lot more than many "winter" greens.

Simply don't attempt to grow any crop that originated in the temperate climes (which includes collard (or any brassica) and chard. Save yourself a lot of effort, and put it into what works.

I agree, sweet potato foliage makes an excellent cooking green.

Wow, thank you all for the input! How do I get in touch with members privately? Some of the ideas and advice are excellent!

The center can already purchase the local vegetables easily and inexpensively and I believe I won't have problem growing them, as the okras, runner beans and brinjals sprouted in just 2-3 days! I placed tomato seeds in zip lock/paper towel for a week and they sprout the very next day when I stuck them into soil. If I have sowed directly, they might sprout earlier given how fast the rest germinate. I intend to grow only 2 types of food:

1. The more expensive vegetables,
2. Rare ones only local supermarts offer.

Most of the common vegetables here go for just about less than a dollar for about four lbs! (50rupees/kg)

I am aware that there are locally and commercially grown lettuce, broccolli and other temperate vegetables even in hot regions, so there must be a way to grow them.

I just need to know how to do it small scale first.

"I am aware that there are locally and commercially grown lettuce, broccolli and other temperate vegetables even in hot regions"

How can you be certain that stuff is not imported from a cooler climate, for instance, a much higher elevation?

Since local produce is super-cheap, then the idea of buying bulk seeds by mail and growing back-home-flavored sprouts is kind of clever.

yes from what i have seen in the tropics those cooler weather crops are grown at elevation, way up the mountian somewhere there are probably some farmers with terraced fields growing broc and cabbage, spuds and the like.

If I'm not mistaken, the central part of Sri Lanka is quite mountainous with an average annual temperature as low as 60 degrees F in some places.

In Hawaii, during "cooler" (still considered warm in the day to most of us not living there) parts of the year they can grow cabbages in the upper elevations.

A lot of lettuce/salad green/tomato production happens almost exclusively in greenhouses. Lettuce/greens are grown like this for climate/pest control and tomatoes almost exclusively for pest control. It can get sneaky hard to grow tomatoes out there even though it's a near ideal climate at lower elevations year-round. The pest pressure (especially birds) is just too high to grow commercial stands of slicer tomatoes.

In Columbia at 8000 ft -ish I saw all kinds of typical temperate-climate crops being grown at large scale. No doubt some of it gets sold at low hot-climate elevations.

I've visited an air-conditioned nursey, that's why. Singapore, where I am from, also has small scale commercial nurseries, wholesaling temperate crops at premium prices.

I guess it is all about finding innovative ways to keep the air temperature low in a greenhouse, either that or another way to produce the necessary energy cheaply, or perhaps even freely.

I will work with the more expensive local crops first. Shall start small, grow big. Thanks all again for the awesome input!

You know, makes me wonder if there are solar powered air conditioners out there. I mean, makes sense to me, the time you would want to use them also coincides with when you get the strongest, most direct sunlight...

Yeah! Well, hopefully we don't get fried in the next solar storm at the end of this year.

Free energy will be made available to us all within the next decade or so, I believe. And we can have lettuce in the desert. lol..

Solar maximum won't be until mid to late 2013.

Like some others have said, stick with cool weather crops in cool weather mostly. I grow these even in winter simply by covering the crops when it's going to freeze. They really have a head start in the spring so the growing season is longer. Varieties do matter. I've found the Black Seeded Simpson lettuce grows well. I've had tremendous luck growing Swiss Chard...almost year round...no problem.

You also might try checking with some of the CSA's in your area because if it can be grown, they will grow it and know the varieties. Check out Barefoot Farmer. In one of his books he mentions varieties (his first one, I think).

Mahinda May i know how did this go about? how was the gardening experience,