Sometimes it isn't practical or possible to rotate as you should. If you start your own seeds, plant varieties that are the most resistant to diseases experienced in your area. If you buy your starts, ask the grower for the ones recommended if rotation is not possible.
Thanks @Don Alaska , as always for your excellent advice I’ll but the seedlings in punnets …as I’ll be away when I should be planting seeds Interestedly I had 2 cherry type tomatoes come up in my garden last spring , and when I arrived home from being away 7 weeks What did I do ….. I went out the back / side areas where I have my gardens and checked how it had fared the wind / some rain / cold , to my surprise I picked close to a kg of ripe mini tomatoes from one of those that came up …( I’d pulled the other one out ) that climbed my plum tree , the surviving one has more green tomatoes on it and is putting on new growth so ,it may grow / survive to see another season