If you are planning to start off now pls hold no use at alll .. other than regular greens...
u could sow by mid august ... carrots & radish, bitter guard, beans (all kinds), snake guard, ridge guards, pumpkins , ash guard .. in short u can grow anything water daily ..tomatoes too...
i ahve grown almost all varities of veggies here in doha ... and still growing ... chillies greens (spibach), coriander and mint can be grown now provided u water them twice in the morning and evening and take good care...