August and September are the hardest months of the year for plants because of intense heat, dust and dryness. Check your garden and give an extra deep drink to anything that looks stressed. It's best not to plant in these months if you can avoid it. Also postpone any transplanting until November when days are cool.
September is a good time to start planning any new garden projects for next spring. Measure out the area at a scale of 1/4"= 1' or 1/8"= 1' depending on how large the area is. Note any building spaces adjoining the area including doors and windows as well as porches, posts and terraces. Add in the plants you're retaining and leave out the ones you want to get rid of. Also note any plants to be moved. Then overlay your drawing with a piece of tracing paper and get creative. Layout any hardscape, any water features and circulation (pathways) first. Do you need shade? If so look at your shadow in the afternoon and see which way your shadow falls (the length will vary depending on time of year - shortest in summer and longest in winter). Then you can see where an arbor or tree placement is most appropriate. Next plan for other trees and large shrubs working your way down to lower groupings and finally border plants. Be sure to create clusters of the same plant varieties for continuity and use variety for interest. Use some of the same plants on both sides of a pathway to make the areas read as one and seem larger. Remember to think of color, fragrance and plant changes such as going decidous through the year.