I have an approximately 8-month old silver tree (Leucadendron Argentum) seedling that I grew from seeds I got in South Africa. I planed them in a very well-draining soil composed of sand, pelite, and peat and watered it every 5 days or so. It has been in a spot with direct sun for at least 3-4 hours/day and protected from high-winds whenever possible. Outside temps have dropped to the 40s so I have brought it inside to a bright south-facing window.
It has been relatively healthy until the last month where some of the newer leaves (but not the older ones) have been turning brownish/gray and crispy. I have increased watering frequency to every ~3 days, but not sure if its helping.
Any advice on the problem based on the description (wasnt able to add images for some reason)?
Its a beautiful plant and I'd hate to lose it.