I'm NOT in a tropical climate -- far, far drier. But what Nik said: nikthegreek(9b/10a E of Athens, Greece) What the roses may find stressful as plants is not the heat or humidity but the lack of winter coolness That rang true for me. While not tropical, here in coastal Southern California, we also have No Winter Chill. In that situation, Austin roses that were perfectly well-behaved elsewhere morphed here into Jolly Green Giants ... growing 12- 14-ft. tall, and blooming only at the very top. If we cut them down, they responded by hunkering down and growing back to 12-ft., to produce one large bloom or cluster. After a few seasons of that, we had to acknowledge the advice we had received that these were not the ideal roses for our conditions. We still grow a few Austins . . . Golden Celebration is great here (but would blackspot for you). Prospero is one of my all-time favorites, as is Belle Story, and my DH loves Cymbaline.

Hi guys, thank you for your kind words! @houstontexas123: Yes, i have tought about mulch. Actually i think that it may be useful. BUT: 1) During winter i don't want the ground to be insulated: i want it to accumulate as much heat as possible, so, the use of mulch would be limited to summer. 2) Mulch is basically rotting vegetable material. While it isn't seriously dangerous for a very healthy plant, rotting vegetable can become host of pests wich on the long run can also affect the plant. During this winter i have had a really hard time stopping the spreading of a bacterial disease from a flowering panicle to the plant, i don'teven want to think what can happen if i only had some decomposing wood inside the structure :) 3)Water isn't really an issue. This year we had the 2nd hottes summer since 1800 and the driest since last 50 years, and i managed to water it enough, so while i appreciate people wich save water, i also recognize that my mango uses really a small percentage of my water consumption (nothing compared to my lawn, wich, this year, died almost completly). 4)around the mango live 3-4 tortoises, wich appreciate grass for food and shelter. :) So i remove grass just two time a year. This tear there hasn't been any need because the lack of rain didn't let the grass to estabilish. @mangodog: Hi Gary! Yes, i think i'll simply remove some parts of the cover. If i don't open it at least a bit, the plant wil literally cook. In January, during sunny days, i had 77F inside with 50F outside, and the sun was just 20 degree above the horizon. In march i had already 100+ inside. Can you imagine the temperature at the end of may? The plant would probably have its leaf scorched. I used some fertilizer this year, too. Last year i simply used potassium, but this year i used some 1-2-4 in june and liquid potassium two weeks ago. I agree with you, it helps. At least, without it my ctirus won't do anything (flower, fruits... anything). I'm not sure how to use it on mangos, expecially on my plant in ground. My experiment will continue unless either it will be clear that i can't hope to eat my own mangos, or i will be able to eat them. :) Did you already harvested your manila? I guess you did since last time i saw them in one of your reports they were pretty filled. @Doglips: Oh, 2-3 weeks of freezing weater a year? You live in a beautiful beatiful place. :) Here frezing risk start on november and ends past the half of april. Natually, even after then, night can be pretty cold. We have just 3 months suitable for tropical growing. Maybe four, on good years. Anyway, if you ask me, the biggest problem isn't the lenght of the winter, but the fact that climate keeps steadily cold all the time during winter. The average temperature of January is 51F. And you can't hope for much more. 59F for january, here, is already exceptionally hot. And lasts two months, this way. In the meantime the climate keeps rainy, damp, without much sun. And even in the brightest days, the best you can expect is 9 hours of a low sun. Overall the climate ideal for spreading bacteria and fungine infections. If we could get at least an hot wave, every now and then, the plant could recover a bit, start growing again: for some plants this is the best method to avoid dying. Anyhow, i live here, and there's much to do about it. The funny thing is that in the very south of italy, on the better locations, i have seen people growing delonix regia in their backyards.

Study Clouds Link Between Pollution and Rain By Robin Lloyd Special to LiveScience posted: 23 December, 2004 7:00 a.m. ET A team of scientists has looked at clouds from both sides now and found more bad news about air pollution and global warming. For the past decade, some scientists have thought that small air-polluting particles produced by the burning of fossil fuels and then sucked into clouds acted as seeds for new cloud particles, plumping up polluted clouds with numerous and smaller cloud particles. Smaller cloud droplets are less efficient at producing rain, and the thinking was that less precipitation would yield thick balls of clouds that reflect more sunlight away from Earth. The cooling effect was thought to be strong enough to cancel the contribution of atmospheric warming from increased carbon dioxide in the atmosphere. Carbon dioxide is the major greenhouse gas produced by human consumption of fossil fuels, along with methane, nitrous oxide, and other carbon gases. Ship tracks, the long lines of clouds downwind of ships, provided a nice opportunity to study the effect of exhaust particles, called aerosols, on clouds. However, pesky data turned up. Sometimes scientists measured more water and thicker clouds in the ship tracks. More often, less water was measured in the tracks, just the opposite of what was expected. The new study involved creating a detailed three-dimensional model for the interaction of air pollution with clouds and found that the mitigating effect of pollution only works when the air above clouds is humid. The model was tested against real data from the field and found to be very realistic. "Our findings indeed indicate that aerosol pollution will not save us from greenhouse warming to the extent that has been widely thought by the general climate community," said Andrew Ackerman of NASA's Ames Research Center. A research paper on the results by Ackerman and colleagues at the University of Tasmania, Lawrence Livermore National Laboratory, and the University of Colorado, Boulder, was published in the Dec. 23 issue of the journal Nature. The teams approach involved a model with 45 ingredients or variables at each of a half million grid points to represent a cloud space spanning four square miles and one mile thick, solved to predict the interactions of water droplets in clouds. The approach was so complex that mathematical solutions required three days of running simulations divided into smaller pieces simultaneously on 32 computers at once, a process known as cluster computing or parallel processing. A big surprise came when the model, in one case, cranked out a relatively dry cloud despite an increase in aerosols, or air pollution. No precipitation was falling from the cloud, as well. Thats when the team noticed that the air above the clouds in this strange case was much drier than in the other meteorological cases. "We hypothesized that the dry air above the boundary layer was reducing the precipitation, and thus leading to the unexpected behavior," Ackerman told LiveScience. Sure enough, by drying out air above the simulated cloud layer, the team was able to reverse the response of cloud water to pollution in their models. The dry air resulted in less drizzle from the cloud and more rapid drying as it sucked in more air from above. Ackerman and his team also learned something about "non-precipitating clouds." It can be misleading when studying the effects of pollution on clouds to ignore small amounts of precipitation locked in clouds that do not rain. Actually, the movement of cloud droplets slowly falling within clouds can be the subtle driver of the process that results in relatively dried out, polluted clouds that are less effective at offsetting global warming.

Answer to Brad: I m located in Quebec, the weather is quite cold here, also the electricity cost is very low compare to the rest of north america, so comparing to me might not be very useful. I would suggest that you compare your electricity consumption with you neighbors ( ask your neighbor) or colleagues at work, that would give a better idea how your heat pump performing, try also to find out if your your utility company has a tool in there web site where you can compare your consumption with your peers. Hydro Quebec (our only utility company) has tool that gave me how efficient my home versus similar sizes home.