Protecting container plants in extreme summer heat is a challenge many gardeners face. Note that the plants in soil bed do not feel that much heat as compared to the ones in containers. In my case, i have got majority of my container plants on my terrace, the floor heats up in summers and the roots of plants at bottom of container are stressed. I had to water every second day to protect them. Last year i lost some of my plants because of that. Here is what i am doing this summer and this is going good so far.
Mulch: The best mulch components are leaf mold, coco peat and some organic matter or humus. You can also include, shredded newspapers and card boards. Remember, leaf mold cools the soil more than anything else. See the following arabian jasmine, though in soil bed, i have mulched it with leaf mold and coco peat around 2 inches depth.
This is how it will look closely. Don’t forget to keep the mulch away from the main stem. Mulch will protect the plant from outside heat but not the bottom heat which is coming from the floor and stressing the roots.
Type of container: If you see below, this is my murraya exotica plant in an 18 inches clay pots. If you use terracotta pots, the terracotta color will protect the plants from heat however plastic pots heat up in direct sun. I like clay pots and they provide better protection from heat as well. The mulch of leaf mold and coco peat is 2 inches deep.
And last but not least container gardeners should try to plant drought tolerant plants as much as possible. The plants which are native to south africa, brazil, australia and mexico are very suitable to our sub tropical hot climate. The temperature outside temperature on my terrace right now is 110F which is quite challenging. But the mulch and pebbles tray are doing a great job till now.