Flowers and Bulbs
August is the last chance to plant the dormant bulbs of late summer and fall blooming lycoris and fall crocus (Colchicum), which begin blooming in September. August is also a good time to buy and plant Salvias.
Roses and Shrubs
You should prune your roses this month to get them ready for the fall blooming season. The exception is ramblers, climbers, and some varieties of old garden roses, which bloom on growth made the year before prolifically in spring and early summer. These should only be pruned now if absolutely necessary now (it's better to prune these type of roses earlier in the summer). Now is a really bad time to plant roses and shrubs, as the August heat is almost certain to kill new transplants.
Trees
This month is your last chance to plant palm trees, which will need time to get established before the cold. The heat makes this a bad time to plant other types of trees.
Vegetables and Herbs
Even though the weather is hot, there are many vegetables you can plant this month. Find out which ones are good to plant where you are
here.
I'm just an amature garderner...not an expert. Most of the information above came from the book
Month to Month Gardening in Texas.
