Today has been the first sunny day in a long while, and some of my aloes sat in the sun of a south-facing windowsill for the first time. Two of them were in an office before, never getting direct sunlight.

When I came home, I noticed a new brown tinge had appeared, most pronounced at the base of their new leaves, and less elsewhere.

I learned recently that aloes need to acclimatise in order to stand full sun, but I wasn't expecting such a reaction on the first day.

My questions are:

  • Is the damage permanent?
  • If not, where should I place them to make them recover, and for how long?
  • What schedule should I follow to make them acclimatise to the windowsill?

Pictues below. The brown tinge looks much more pronounced to the naked eye than in the pictures.

The two plants on the right come from an office setting where they received dim indirect light, until I brought them home last week. Today was their first exposure to full sun. The pup is Aloe Variegata.

Affected plants

Detail of the browning:

Browning on middle aloe Browning on pup Browned inner leaves

  • As it looks like this is a basic question that may have already been asked, I wanted to mention that I searched fairly extensively before writing this question and haven't found a clear answer to my question.
    – kettlepot
    Feb 15, 2017 at 18:54
  • 1
    In the last picture you seem to have Haworthia attenuata, not that it helps with something.
    – Alina
    Feb 15, 2017 at 19:18
  • Oh! I actually thought it was an aloe, thanks! Out of curiosity, do Haworthia need different care than Aloe or can they be treated the same?
    – kettlepot
    Feb 15, 2017 at 19:33
  • What's the name of the second plant?
    – Augustin
    Feb 15, 2017 at 20:59
  • Google says tiger tooth aloe but I'm not 100% sure.
    – kettlepot
    Feb 15, 2017 at 22:00

1 Answer 1


Haworthia do not like direct sun, especially when kept as a houseplant - I agree with the ID of Haworthia attenuata, so yes, it does need a different situation from a true aloe, so somewhere with good light but not direct sun.

Not sure what your aloe is either - maybe A. mitriformis, and they do cope with sun. If its winter where you are, I'd be surprised if the sun caused a problem, but if the plant was exposed all day to unexpected sunlight, it might have caused a problem, though that's difficult to detect from the photos.

Assuming sunlight has caused the trouble, stand it in sunlight for increasing periods, rather than leaving it exposed all day, so give it a couple of hours of morning sun, then move it, and increase its exposure over time. As for the small plant in your images, I'm not sure what that is, but you'd need to be careful about sun exposure just because its small, so a similar arrangement - a small but increasing amount of exposure over time.

  • Sorry, I forgot to mention. The small plant is a pup of Aloe Variegata.
    – kettlepot
    Feb 15, 2017 at 19:48
  • Ok - same advice applies.
    – Bamboo
    Feb 15, 2017 at 19:49
  • If the plant acclimatises correctly, it should show no sign of browning, is that correct? Should I give it a few days of rest in indirect light before I start acclimatising it?
    – kettlepot
    Feb 15, 2017 at 19:50
  • Yes, that's right, (if the cause was actually the sun) in regard to the Aloe varieties anyway, not the Haworthia, keep that out of sunlight. If you're in the northern hemisphere, sunny days often mean much colder nights, so I'm wondering if the shock of temperature drop on a windowsill after a sunny day might have had an impact, especially if the window is single glazed, or you drew curtains or a blind between the plant and the room, but I don't know where you are.
    – Bamboo
    Feb 15, 2017 at 19:51
  • The absolute lowest temperature my indoor thermometer in my windowsill reports is 11 degrees Celsius. That's still in the acceptable range, right?
    – kettlepot
    Feb 15, 2017 at 20:45

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