To maintain moisture in the soil, mulch your plants after rain with composted bark, leaving soil clear near basal stems. Keep on top of the watering of containers and hanging baskets as, even after quite heavy periods of rain, they could still be dry so make sure that you really do soak the compost.
Compost all your waste plant material. Place lawn mowings, plant stems, haulms, flower-heads, and kitchen waste in an open-ended compost box or bin, keep it nicely moist, and treated with a compost activator, to rot, and provide manure for future use.
The one real plus about any patio is that it is ideal for masses of pots of colourful summer flowers. These pots can then be extended through the Winter and into Spring with bulbs and Winter bedding to give your patio a longer lasting pleasure. Do remember though that the more containers you have, the more watering you will have to do during hot periods and the more dead heading and trimming you will need to do.