We love Solar Caps, and so do our tomato starts! Solar Caps consist of a sturdy welded galvanized steel wire frame that lasts for years, over which you drape the water-filled plastic bag that comes with the kit. By positioning the Solar Cap where your tomato (or other warm-season veggies) will be planted, in 5-7 days your soil will be warm enough for planting (55+ F). Following planting, Solar Caps form a personal greenhouse for your veggies, which improves growth throughout the season and won’t tip over or collapse. They protect plants from drastic spring temperature fluctuations and from nightly cooling. We leave the Solar caps on our tomatoes though the season, enlarging the opening in the top from a small slit at first to a fully open circle when plants have put on height and weather is consistently warm. We’ve had great success using them for many years and regularly plant our tomatoes by April 15!