Summer can be a time of fantastic growth for your Portulacaria afra, but it is also a season in which the needs of these trees can dramatically increase.
Inside houses/rooms without air conditioning, the Summer will create much warmer temperatures and the water needs will be greater for your bonsai. The increased magnification and intensity of the Summer sun will also dry out trees faster that are near windows even for indoor spaces with air conditioning - the ambient humidity created from air conditioners is also drier. It is important to be aware of these variables for your bonsai’s best health.
As your P. afra is happy to be outside when temperatures (including night) are above 50f, Summer is a season when people with the option/inclination for keeping their bonsai outdoors are already doing so. For bonsai outside in full sun on the hottest days of the Summer, these trees will require watering twice a day. It can be a better idea to move your P. afra into partial shade if the watering needs become too high in direct sunlight, they will still be getting enough sun in a shorter span of time due to the seasonal shift. Be aware that, at the least, daily watering is often advisable for your bonsai kept outside in the Summer.
This is all to say, regardless of their location, check your trees and be sure to pay more attention during seasonal changes like from Spring-to-Summer. It’s still not advisable to overwater your trees for long periods of time, but be aware that more hydration in the Summer, as with people, is often required.
Refer to our article from Sean the Magnificent on watering practices and Cash Cab questions.
Check our article on repotting for questions about Summer repots.
Summer can also be a time when bonsai are at risk from insect pests. [Do we want to link my PowerPoint on pests from the study group?]