Prune tomato plants as they grow, focusing on removing side shoots from the juncture between leaf and stem. This encourages your tomato to focus its energy on growing tall. Determinate plants stop growth at a certain point making naturally bushier plants, whereas indeterminate tomato varieties will continue growing up until the first frost date after the summer. It can be a good idea to nip off the growing tip of your indeterminate tomato plants when they reach the top of their support to focus their energy on producing and ripening fruits. Remove the lower leaves of your tomato plants in July when fruit trusses start to form. This allows the sun to get to the fruits and improves airflow which reduces the risk of blight. Take the old leaves away from where your plants are growing and add to the compost heap or bonfire.