Heirloom Tomatoes

Heirloom tomatoes are tomatoes of the most original kind. They are not hybrids, and they have not been genetically modified or enhanced. Any changes in genetics are due to natural cross-pollination. Supermarket tomatoes and, unless noted, seed catalog tomatoes are hybrids. They have been bred for a specific market or growing condition.

Heirloom tomatoes are grown from seeds that have been saved over the centuries from plants selected for their naturally occurring desired characteristics. Some types are best for paste, some for slicing. Some have naturally adapted to grow and produce in cooler climates. Some are determinate (grow to a certain size, produce fruits at once, then die back) and some are indeterminate (vining types that continue to grow and produce until frost. Color is a natural characteristic, as is size and shape.

Growing heirloom tomatoes is much the same as growing newer hybrid varieties. Start your seeds indoors about 10 weeks before the expected last frost in your area. They will require plenty of light and you may need to supplement a sunny windowsill with additional artificial light. They should be kept fairly warm and out of drafts. Before you set tomatoes out in your garden, you need to harden them off by setting them out in the warm spring sunshine for a few hours a day. Gradually increase the outdoor exposure until you are ready to set them out permanently. Soil temperatures should be about 70 degrees when you set out tomatoes. Plant them deep, leaving only about three leaf bracts above the soil. Roots will grow from the underground stem and will give the plant additional strength and nutritional support. Keep tomatoes lightly fertilized and well watered. Heirlooms may need extra attention since they do not have genetic modification for disease resistance.