Sunburn in winter?

mughal113 · Post by **mughal113** » Thu Jan 03, 2008 6:47 am

Hi all,

Winters here are not too harsh. It rarely goes below freezing. In fact, it hasn't touched zero yet this season. Days are bright and dry with temps going as high as 25C. I have left all my cacti in full sun and keeping them dry. But I can see many of them getting slightly (some seriously) sun-burnt. Is the sun without water causing this? I have seen that some of them do want to grow (growing new spines). Should I start watering them or get them some shade? Thanks a lot.

Eliott · Post by **Eliott** » Thu Jan 03, 2008 8:32 pm

The sun is bright and can damage plants that don't like full sun whether it's winter or not. So, if a plant doesn't like full sun in the summer, I wouldn't put it in full sun in the winter just the same.

At 25C, the risk of them freezing is probably pretty low. I might hold back on watering them quite as much as if it were 40 or so, but I'd definitely not hold back on watering entirely just because it's winter.

Seasons are man-made concepts that roughly correspond to nature, so keep in mind that your plants don't have any concept of whether the calendar says it's winter or summer. What they do have a concept of is temperature. If it's too hot or too cold, they notice that, not what a man-made calendar says. So, keep this in mind when taking care of your plants.

In all, I think it probably depends a lot on what types of cactis you're growing, but take the above into consideration.

Stuart E · Post by **Stuart E** » Fri Jan 04, 2008 9:36 am

Eliott wrote:Seasons are man-made concepts that roughly correspond to nature, so keep in mind that your plants don't have any concept of whether the calendar says it's winter or summer. What they do have a concept of is temperature. If it's too hot or too cold, they notice that, not what a man-made calendar says. So, keep this in mind when taking care of your plants.

They also respond to day length, some species being short-day growers, others growing when the days are longer.

What is the air movement like around your plants, Mughal? Is the air very still?

Post by **daiv** » Fri Jan 04, 2008 9:37 pm

I would also add that if your plants were not in full sun and then moved to full sun, they can get burned. However, if you've had them in full sun for a while and just now you are noticing the problem, I don't think that is sun burn.

mughal113 · Post by **mughal113** » Sat Jan 12, 2008 7:41 pm

Hi,

Sorry, I lost track of this post. Well Daiv, most of the plants have been facing sun for quite some time now. They grew well during summers in full sun and this sunburn only started becoming visible in December. The situation has improved after I started giving a bit more water to the plants. I've seen that most of them want to grow during the winters.

Stuart, yes, winters here are not much windy. Could that be the reason?

Thanks.

Eliott · Post by **Eliott** » Sat Jan 12, 2008 11:29 pm

Are you growing them indoors or outdoors? Indoors, if you have a heater and stuff, the air can be a lot drier than you'd think, so they still might have a bit higher water-expectancy than other places. This could've been the case, since you said it improved with more watering.

Where I live in Tennessee, the weather is almost identical to that of Lahore. The temperature there might be a bit warmer in the winter, but by and large from what I've seen Lahore and my part of Tennessee have similar climates.

mughal113 · Post by **mughal113** » Mon Jan 14, 2008 6:40 am

They are growing outdoors in full sun. Winters are dry here, very dry in fact. Now I feel the dry air complemented by direct sunlight might be the culprit.

Thanks for your help.