Even though the home canner has canned plenty of tomatoes, it may be
desirable to keep some of the fresh fruit. Keep tomatoes in the garden
as long as possible. You can protect against early fall frosts by
covering the plants with burlap or old carpets in the evening when frost
is predicted. Polyethylene may also be used but injury will occur
wherever it touches the plant.
In the summer, tomatoes should be harvested when fully vine-ripened for
best quality. Pick when the color is a dark red in red varieties. During
fall when frost is likely, mature green fruit can be picked and it will
develop a red color when kept in a fairly warm place. The fruit is in
the "mature-green" state if the tissues are gelatinous or sticky when
the tomato is cut and the tomato interior is yellowish. Immature green
tomatoes don't ripen satisfactorily.
To check your judgment, cut a tomato in half that you feel is mature
green. If the pulp that fills the compartments is jelly-like, it is
mature green. The seeds are dragged aside easily by the knife and not
cut through. In immature green tomatoes, seeds are easily cut through
and the jelly-like pulp has not yet developed. Usually you can recognize
the mature green ones by their glossiness, less hairiness, and more
whitish green color.
You can pick mature-green fruits and bury them in deep straw or place in
a room where the temperature is 60° to 70° F. The tomatoes will ripen
over a period of 3 or 4 weeks. Sunlight is not needed to ripen
green-ripe tomatoes, so don't bother to put them on window sills. They
ripen satisfactorily in the dark. Generally, tomatoes store best at 55°
to 60° and ripen at 70° or room temperature.
You can wash the mature green fruits in a weak solution of household
bleach and then wrap in paper to store and ripen.
Some people pull up the vines just before frost and hang them in the
basement or garage to ripen their fruit.