What Causes White Spots on Home Grown Tomatoes?

Growing tomatoes at home can be a great way to save a little money on groceries while providing a nutritious and versatile item for your diet. Plus, homegrown tomatoes taste great. Yet it is more difficult to grown one's own tomatoes than to purchase them from a store. One common problem is white spots seen on the fruit, under the skin or inside the tomato. These may come from various sources.

Small, cloudy white spots just under the skin of a tomato are caused by stink bugs biting the fruit. In general these spots are cosmetic and the fruit is still good to eat, although it will spoil faster after picking. There are insecticides, organic and otherwise, that can deal with stink bugs. Another solution is to patrol the garden each day with a hand-held vacuum and get rid of the stink bugs one by one. Since stink bugs are attracted to the fruits which ripen first, it's possible to use a different crop of tomatoes to keep the bugs away from the main batch, or to lure the bugs away with a patch of ornamental millet grown somewhere away from the tomatoes.

Hard white spots inside the fruit are signs of uneven ripening, which can be attributed to bad nutrition, high temperatures or disease. To fix the nutrition, use a fertilizer with less nitrogen and more potassium, especially when the fruits get larger than a quarter.

White spots developing on the skin of the fruit which become holes in its surface can be a sign of disease like a bacterial speck. The areas can be cut away and the fruit can still be eaten. As the disease can spread from plant to plant, care should be taken in the garden to not splash water from one plant to another. In the off season, clean up any debris on the site and rotate the garden.