A hydrothermal vent is a fissure in a planet's surface from which geothermally heated water issues. Hydrothermal vents are commonly found near volcanically active places, areas where tectonic plates are moving apart, ocean basins, and hotspots.
When to Set out Tomato Plants. The best time to set out tomato plants is after danger of frost, which is usually anytime in April, May or early June. If you started seed indoors, the seedlings should be about 6 to 8 inches tall and hardened off before transplanting outside.
Transplant tomato plants when the soil and air temperatures have warmed to 60 degrees Fahrenheit. Along Coloradoâs Front Range and Western Slope, this is usually in mid-to late May.