Speeding up Tomato Harvests

Turning Green Tomatoes Red While On The Vine

Remove flowers.

Cut stems back to a fruit.

There’s a few techniques to encourage tomatoes to ripen and to prolong the harvest.
Remove:

existing flowers and buds. This allows the plant to concentrate its energy on ripening existing fruit instead of growing new ones.
stem ends. Cut just above a cluster of ripening fruit.
lower leaves especially ones that touch the ground.
diseased foliage and fruit, split and overripe tomatoes.
small fruit to allow bigger tomatoes to mature.
excess fruit on overloaded plants.
small and new suckers
any diseased, sickly, buggy and sick fruit

Apply Epsom Salts: Provides magnesium. Mix 2 tablespoons of Epsom salts to one gallon of water. Either apply the solution to the soil or mist the foliage. Or apply a cup of Epsom salts around each plant and water it in well.
Stop watering. The lack of water encourages ripening, however, don’t allow plants to wilt.
Milk: Spray plants with 1 part skim milk and 9 parts water. Repeat every two weeks to deter fungi.
Cover plants at night. This not only keeps plants warmer it keeps plants drier reducing blight and other diseases. Use breathable fabric such as tablecloths, floating row covers. Don’t forget to uncover plants in the morning.
Watch for frost. Extend harvest by covering plants when frost is predicted. Use floating row covers, sheets or other breathable fabric. Plastic has no insulating value.
Inspect & harvest daily

Remove suckers.

Remove rotten, diseased tomatoes.

There's certainly more to growing veggies than this article. Check out the links below for more information.