In previous answers, I've mentioned our general lack of success growing root vegetables in North Texas. Carrots and beetroots do not do well at all - roots are few and small. Onions and potatoes do better but watering seems to be a problem.
Apparently we are 8a/7b on the USDA hardiness zones. That looks about right (8a, lows of 10-15F sounds normal, but this winter was more like 7b, lows 5-10F). Summer temperatures have highs in the 90s / low 100s. Last year (an extreme summer) had over four weeks of highs over 100F - usually it is just a few days or a week at a time.
Rain tends to be in the form of heavy storms during spring and autumn. Nice persistent English rain only comes if we are lucky enough to get a tropical cyclone large enough to survive 300 miles inshore. Unfortunately such events are large enough to make the international news.
Anyway, potatoes seem to work best if they are well watered and planted early (e.g. ones that started growing in the cupboard that get planted on a whim in Autumn). Onions seem to be a war of attrition with most sets eventually dieing but a few survive and become large enough to eat. In both cases, these are veg that don't mind being in the ground for winter - so I think I am giving them sufficient growing season before the dry hot summer strikes.
How can I improve my success with onions, potatoes, and traditional root vegetables (eg. carrots and beetroot)? It seems a plant-early winter crop approach might be best, in order to maximise the growing season?