Where in Florida are you?

The heat is a problem with some Genera. The upper limit for some is about 90F. Of much more importance is the strength of the sun in summer (and here in winter) Just about to take one layer of Shade-cloth off my shade-house leaving about 50%.

B. nodosa is a high-light orchid and can take more light than than the general run of "Cattleyas" . But even it needs an appropriate amount of shading depending on the season

You have to be aware of humidity levels. Intense Sun + temps over 90F + very low humidity are dangerous conditions.

That is why temperature zones are a bit misleading. I am sure 10b here is very different to 10b Florida.

Tell the posters where you are in Florida.

I'm in the Jax area. Here I worry about July and August and today it was 90. Sigh!

Hi Bea. I'm in Sarasota which I think is quite warmer than Jacksonville. My Nodosas, and D. aggregatum get full sun all day. I have 4 Nodosas and two hang under trees, the other two are under cage screening over my patio. I do not use shade cloth over them.

Some orchids show signs of stress during those months. Most of my Oncids are under shade cloth with my Phals. Catts are separated according to genera. Some can take high heat and sun, others cannot. I watch and move them around. I'm always moving plants as the weather changes. I find the shade from trees seem to work the best. My guess is the movement of the leaves and the coolness from the shady ground beneath. I also hose everything daily if needed to cool them down.

My hard cane Dends seem to suffer. I found it strange as they grew in full sun in NY without a problem. Here they are already showing signs of stress and I've moved them into more shade. I've had more problems with my hard canes than any other orchids.

But the plants you mentioned stay out in the heat and sun all day throughout the summer. They bloom well and don't seem to have a problem Just water more often.

Jane

It was like a hot July day, not April! March has been the second warmest on record. April looks to be the same. I want my money back. The best weather of the year never showed up. My shade house at 1:30 pm was 97 degrees. I was able to bring the temps down to 91 by flooding the floor, concrete pavers. The evaporation allowed me to watch the mercury drop slowly. This weather pattern in not normal. The fronts have been stalling and they create the non typical South West winds. As this odd wind travels over the hot land and when it finally gets here it is very hot. Our prevalent breezes come from the east to southeast blowing over the Gulf stream. That is what most of the time keeps us warm in the Winter and cooler in the Summer. We are uniquely subtropical at our latitude due to the Gulf Stream. I would say Jane is the warmest, bea second and Martin County coolest in Summer. Except on a SW wind. Winter, I'd be warmest, Jane second and bea coolest.

B. nodosa is tough and will take the heat. My guess is a perfect insitu would be mounted or on an oak or palmetto getting direct morning sun with a shady bright afternoon. I have them planted in pots, on trees and mounted on cork. They are all robust. They prefer to be watered every day. In pots it is 100% lava rock. On busy days the tree mounted might be neglected to be watered. The flowers may be a little smaller and slightly fewer, but still healthy.

One of my oldest orchids is a b. nodosa. I tied it to a post on the shady side for my pleasure. I did not know it wanted to be on the morning sun side. Did not flower for 2 years until it grew around to the sunny side. It taught me a lesson and became the owner of that post.

As easy as the brassavolas grow here and from the New World in Central and South America would have been natural to Florida if us humans did not show up for a million or 2 years later. They just seem so at home here. If the plant could talk it would ask for direct morning sun, afternoon very bright shade, watered every day with modest water retention. And will tolerate much less than ideal. The winters in Jacksonville might be to cold on the coldest days. The may not survive on trees. But I would try one on a tree to be sure.

Arthur for us it's a combination - brutal heat and extremely intense sun and that's why I'm asking south FL folks what they do. If they leave the plants I listed outside so could I. I tried to get thst info from someone in my local orchid society but no one responded.

Humidity is usually not an issue. Even though generally humidity is lower the hotter it is, in FL it's very hot and very humid at the same time.

Florida has the longest summers but not the hottest. Either the deserts in the Southwest or most of the country will get a day or 3 or more in the 100's. We have more humidity. If you can shade it from the afternoon sun they will manage.

Consider the other Brassavolas if you enjoy nodosa. Little Stars, a primary cross, blooms in Oct. There are others so you can stager the bloom and have aroma filled evenings for several months...

Thank you all. Great advice. My plants thank you. They will enjoy the great outdoors.

Shaved, mine do not seem to have a problem with full sun. Of course, some are in the lanai under the screening. I tend to forget about mine because they never show any sign they are having a problem. The nodosas growing under trees get a lot of morning and afternoon sun. Also, I forget to water them. I get good growth and flowering. But I suppose giving them afternoon shade makes sense. Few plants can handle full, Florida afternoon sun.

Jane you mentioned your dends are having more issues with full sun here than in NY. Perhaps they are are more touchy about the sun's intensity than other orchids. FL is 800+ miles closer to the equator than KY where I moved from and even more for you. That means the 90+ degree sun here is more intense than up north. I noticed my bed of perennials has issues with the sun in July and August when it's in the 90s daily even though in KY it could also be in the 90s for days on end.

You can't really relate a persons perception of the "feel" of weather to a plants response. Plants will respond more favourably to higher temperatures/sun intensity together with a raising of humidity than would a human. For humans it's the other way around. The critical factor becomes humidity, the others are indirect factors. Temperature recordings are taken of air so it's not "90+ degree sun", it's 90+ degree air. Then of course the other thing is, Florida isn't even in the tropics so the sun there isn't as intense as in some other places where you'll still see some of the species grown in full sun. Again, that is if they have the higher humidity levels. Misting or spraying is a temporary measure as it's soon dissipated, expecially if there's a breeze or wind. It makes controlling humidity in open areas rather difficult, if not impossible. It's far more manageable with trapped air, or to be in an already high humidity environment.

When discussing humidity one must be aware and understand "relative" humidity. There is an impact to the percent of humidity relative to the temperature. At 90 degrees the air will hold a lot more water than at 60 degrees. So 65% humidity at 60 degrees is dryer than 60% at 90, for example.

Latitude matters for solar exposure. On this board there is a difference of how people grow phals. Here in South Florida they do best with bright shade and little or no direct sun. As you go north there will be different answers,

That's right, the relative % humidity is the amount of water in the air compared to its capacity to hold water. As you say, warmer air is capable of holding more water than colder air. That's why relative humidity varies between day and night. The water content remains much the same but that becomes a higher % of a lower water holding capacity of cooler night time air. The reverse happens during the day and plants lose water more rapidly despite actual water content in the air being the same. Misting rapidly humidifies the air around the plant slowing water loss but breezes quickly dissipate and push it away causing water loss to increase again. So plants do get some respite for a while, but it's temporary. It's not unusual for people to blame sun damage on what is predominantly caused by low humidity (apart from when plants are suddenly moved from shade to direct sun).