If you can only get leggy tomato plants here's something that one can do and get great results with them. This can be done with non-leggy plants as well. It can set the plant back some to do this but in the end you'll produce more roots for the plant (see below). This will have several benefits such as more nutrient uptake and better drought resistance. One can also bury the stem straight down instead of on its side. University research found that planting stems straight down with the root ball in deeper (and cooler) soil can improve fruit set in hotter weather. Its probably best to do this in southern areas and trench plant in northern areas (for more warmth).

These pictures were scanned from the book "Dick Raymond's Gardening Year" (ISBN 0-671-50973-X) published by Garden Way Publishing. I also highly recommend "Joy of Gardening". Any of Dick Raymond's books are well worth finding if still in print. They are simple and every informative. (NOTE - this is a non commercial site so images are for educational purposes only and not to be reproduced or copied for any other reason).

here are the results of trench planting.

If you use the trench planting method make sure you place a tag/stake near the rootball so you don't cut the stem underground when cultivating.