Late spring freezes are a problem in northern locations, especially after the plants have leafed out. If your trees have already started to grow and you expect a late freeze, then you should make every effort to protect them, such as using Grow Tubes and other protective measures.Some areas even in Zone 5 can have killing frosts as late as Memorial Day! Dunstan Chestnut trees can tolerate temps as low as -20 degrees when fully dormant and established trees. Chestnuts need at least 100 frost free days from flowering until harvest to fully ripen the nuts. Click for information on properly using frost cloth

(WITHIN LINK ABOVE): Correctly Placing the Frost Cloth Frost cloth is a commercially woven fabric that is light enough to allow air flow and light penetration, but thick enough to help retain warmth from the soil and protect the plant from frost. Always use frost cloth designed for covering plants. Other products made of plastic, for example, can actually transmit cold to the leaves and cause more damage! 

Properly applied frost cloth can protect your frost sensitive plants from the cold even when the temps dip into the 20s! If necessary, the frost cloth can be left on the plants for an extended period of time without the risk of harming your plants. Furthermore, the frost cloth is light and allows the sun to pass through the fabric, thus warming the ground. 

Some people use blankets, sheets or towels to cover plants, but these items are heavy and can break branches. They are difficult to secure on the plant and will also transmit cold to the plants if they become wet. Additionally, they must be removed every morning after the temperature under the covering reaches at least 40 degrees, and on some days this might not happen until noon. Blankets and sheets do not allow for light penetration or airflow and can cook the plant if it gets too hot. 

How do you apply the fabric? 

1. Completely drape the plant from top all the way to the ground, allowing the frost cloth to touch the ground to the drip line of the plant.
2. Apply the cloth before dusk to ensure time to capture radiant heat.
3. Secure it to the ground with heavy objects, like bricks, or frost fabric staples, to ensure that the cloth forms a seal with the ground and traps the warm air that radiates from the soil captured during the day. The bricks or staples will also secure the cloth on the plant in the case of heavy winds or rain.
4. Avoid openings in the cloth that allow the warm air to escape or cold air to enter at night.