What can I grow in a sun-room that gets very hot?

[self-contained]

Hello All,

I have a sun-room attached to my house, which gets loads of light and has loads of window-ledge space so seems a great place to have lots of containers. However, it also gets really, really hot in there, and I can't leave the windows open when I'm out (working full-time) so I can't regulate the temperature that way.

I've just been out to check on the heated propagator I put in there (about the only place I can put one on a window-ledge without the cable trailing across a hot radiator). I foolishly thought that it wouldn't get too warm in there at this time of year, but I was clearly wrong, and I may have cooked the seeds that I started in there last week (I hadn't realised, as before now, I have only checked in on them after dark). However, outside of a heated propagator, at this time of year, it's a reasonable place to get seeds going (much like an unheated greenhouse) and I did okay with that last year.

Unfortunately, as the year went on, it just got hotter and hotter and hotter in there. I don't have a thermometer, but it must have been over 40 C in there at times last year. It was hot enough to kill aubergine plants that were pretty well established last year.

So, my questions are these: Should I just accept that from about early June, I can't have any plants in my sun-room? Or is there anything (easily available, without spending too much) that will not only tolerate those temperatures, but will thrive, even if the temperature is then much lower during the night? I know tropical plants, like bananas, might do okay with the daytime temperatures, but will they manage the colder nights and can I overwinter them indoors without keeping my central heating on when I'm out or asleep?

I'm mostly interested in growing things that I can eat, but I'd be open to any suggestions anyone may have.

Thank you.

[Snoop Puss]

Me, I'd grow peppers, chilies and tomatoes in there if 40 ºC really was the maximum temperature. But you might find that it was in fact well over that. Why not get a maximum/minimum thermometer and check what temperature it gets up to now.

I had a greenhouse that I couldn't spend more than three seconds in most of the day, it was so hot. Best year I ever had for Sungolds, Marmandes, sweet peppers and chilies.

[self-contained]

Thanks for the reply, Snoop Puss.

I visited India a few years ago, when it was running around 39 C, and my sun-room certainly felt hotter than that at times last year, so I wouldn't be surprised if it got well above 40 C. A thermometer would be a good idea, though by the time I know how hot it gets, it may be too late! (I'll probably not be in this house next year).

It killed my pepper seedlings last year, but maybe more established plants would be okay? Are there particular chilli varieties that tolerate high heat well?

[Snoop Puss]

A maximum/minimum thermometer shouldn't cost much, a few pounds at most. My greenhouse thermometer was capable of reading a maximum of 60 ºC but the liquid shot out the top and it broke. Your sun room could get extremely hot. Any plants in direct sun are likely to suffer due to sun scorch as well.

I only grow ordinary chilies, but there are plenty of chili experts on here. Maybe start a separate thread about chilies that can cope with very high temps and see what people suggest.

[nickdub]

Partly depends on what modifications if any you are prepared to make - possibilities include an awning, an automatic opening vent, a large, open water tank .....

[self-contained]

Partly depends on what modifications if any you are prepared to make - possibilities include an awning, an automatic opening vent, a large, open water tank .....

Thanks for the reply.

I rent and may not be living here next year, so I'm a bit limited in changes I can make. The sun-room does have vertical blinds all round and a kind of indoor awning that I can extend under the glass roof. I probably didn't make enough use of those last year but I won't be able to make adjustments to the blinds/awning during the day when I'm at work (as much as I dream of wireless controlled electric blinds).

Installing vents won't be an option. If a big plastic container (or several) filled with water would count as an open water tank, I could give that a try as I don't have any furniture in the sun-room.

[nickdub]

I'd say you'd probably get away with some tomatoes, chilies and a cucumber or two if you are prepared to put in a reasonable sized plastic water container and add some sort of either trickle irrigation or probably cheaper, some from of capillary matting. Some plants will cope with a lot of heat as long as they can get copious water to their roots to cool themselves. It could of course end-up very humid in the room on a sunny day but the plants will benefit from that - they can enjoy conditions more near to a sauna than most of us like.

[Jungle Jane]

A shade cloth might help,I saw one at the garden centre the other day,put it up in the window to stop the sun dazzling the plants,they use them in hot countries,sometimes we have a few days of really hot weather the plants can’t cope with it especially midday through glass. The temperature can affect the peppers & tomatoes fruiting,Ive never been affected by temperatures above forty degrees though,my plants all go outside with the blowaway door open or closed. If the temperature for the day is too hot you could put them in the garden or somewhere shaded?

[Scarlet]

Thanks for the reply, Snoop Puss

It killed my pepper seedlings last year, but maybe more established plants would be okay? Are there particular chilli varieties that tolerate high heat well?

I think seedlings are a very different ball game to plants. When you are growing on your seedlings if they dry out in their little pots they will cook, dry up and die.
I agree with Snoop, chillies, peppers and toms would be my choice. My GH can get to those temps, though I do have vents and keep the doors open. As long as you can keep the pots well watered in the day you should be ok. Chillies can be kept very dry, but the tomatoes won't like drying out.

[veggiechicken]

Just an idea - would a fan help to circulate the air and maybe balance out the temperature around the room?

[bramble]

Can you put up net curtains.
Can you put light fleece over the plants while standing them in water

[Dynamite]

Maybe not for eating but I would go for Bananas.

Regards.......Rob

[self-contained]

Thinking along tropical lines, I picked up some ginger and a pineapple when I did my grocery shopping today. Then, on a whim, I grabbed a papaya too.

I think the pineapple should be okay with just about any heat that gets thrown at it, and the ginger will need shading a bit but is worth a try. My ginger root cost about 20p which seems reasonable, though it does look a bit sad so I'm not certain it will sprout. The pineapple and papaya were more expensive, but they'll contribute to my fruit intake for the week, so the bits I'll grow from are essentially free.

I'll think about getting some chillies underway once I have space in my propagator - will late March/early April be too late?

[KevinM67]

If you were staying for any length of time it would be great to try small lemon trees or olive trees in pots.

[nickdub]

I'll think about getting some chillies underway once I have space in my propagator - will late March/early April be too late?

Early to mid-March would be best probably - no need of a propagator to get them to germinate, a pot with some compost in it on top of a radiator will do the trick - you can then move the seedlings in to the propagator when it arrives.