Dalen Insulated Plant Protector 3Pk

This ingenious 18" tall device allows you to plant and harvest weeks earlier than you could otherwise. When placed around a plant and filled with water, you will have almost three gallons forming a protective wall around the plant. This water barrier works in three ways:
It collects heat from the sun (even on cloudy days), stores it, and then releases it at night when it gets cold.
The wall of water buffers and protects the plant from sub-freezing temperatures by freezing before the plant does.
It offers shelter from cold winds that can easily damage delicate plant tissue.
Insulated Plant Protector has been designed to serve as a mini greenhouse. Its transparency allows the sun's rays in, but it's still strong enough stand up to the elements with multiple chambers for maximum stability.
Easy-to-fill design requires no special assembly or tools – just a hose or watering can.
Perfect for tomatoes, peppers, melons, cucumbers and many other types of plants – especially the heat-loving kind.
Allows you to plant tomatoes up to 6 weeks earlier than usual, meaning you can harvest that much earlier as well.
Protects when overnight lows drop below freezing (32°F) and down to 16°F.