Mountain Princess (Heirloom) Tomato 150 Seeds By Jays Seeds Upc 643451295269 HEIRLOOM. This heirloom, cultivated for decades in the Monongahela National Forest area of West Virginia, was bred for early maturity and makes a good choice for short growing seasons. Start tomatoes indoors 6-8 weeks before the last frost of spring, sowing the seeds in a flat 1/4" deep and 1" apart. Keep the temperature at 70-75 degrees F until germination, as well as providing adequate light in a sunny window or under a grow light Growing Mountain Princess Tomato Seeds: Since temperatures below 55 degrees F can damage production, protect the plants if temperatures drop. A thick layer of mulch helps conserve moisture and control weeds; water the plants once a week, but avoid getting the leaves wet. Determinate, or bush type tomatoes, do not require staking. Harvesting Mountain Princess Tomato: Test the ripeness of tomatoes by pressing them gently; the flesh should yield slightly. The mature color also indicates ripeness. If the stem does not come easily off the vine, cut it with a scissors. Vine ripened tomatoes have the best flavor, but as soon as frost comes, all tomatoes should be harvested, even the green ones. Detailed Mountain Princess Tomato Info: Lycopersicon lycopersicum. Annual. 68 days. 36-48" height. 2-4' spacing. Produces globe shaped red tomatoes that average 6-8 oz. Determinate.