In winter, dry conditions can actually be more damaging than the cold itself. Cold winter air is usually quite dry, and winter winds can remove water from plants faster than the roots can absorb it. This is especially true for evergreens, as water evaporates quickly from their foliage.
In addition, if the ground freezes, the underground water turns to ice crystals which cannot be absorbed by plant roots. Even dormant plants need and absorb water year-round.
Water acts as an insulator. Plant cells that are plump with water will be stronger against cold damage. Likewise, moist soil will tend to stay warmer than dry soil, so a regular watering schedule in dry, cold weather can help protect plants from freezing temperatures.
Follow these guidelines when watering plants in freezing weather:
- If your soil stays frozen all winter, then fall is your prime time – make sure everything is well watered before the ground freezes.
- If you experience freezing weather only occasionally, and you have had insufficient rain or snowfall, water deeply a day or so before a freeze is forecast. Be sure to water the entire root system – a good rule of thumb is to water an area the size of the plant’s drip line.
- Be extra attentive to newly planted trees and shrubs. Not only are their roots less established, but the churned-up soil can allow cold air to penetrate deeper to the roots.
- Water when the air temperature is above 40° F, and don’t water if there’s snow or ice on the ground.
- Water early in the day, so the plants have time to absorb it before the temperature drops at night.
- Don’t wet the foliage. Commercial growers sometimes use sprinkler irrigation to protect plants from frost, but it requires constant sprinkling and should only be done under specific conditions.
- Be careful not to over water. Once or twice per month should be sufficient – the plants will not be absorbing water as fast as they do during the growing season, and the cool soil can easily become soggy.
For more information on watering your plants and lawn, check out these articles and videos:
- Watering Tips (video)
- Watering Lawns (video)
- Home Irrigation How-To (article)
- Calculating Lawn Irrigation Costs (article)
Is it ok to plant trees and shrubs
in December… In Virginia
James, you should probably be OK – I’ve planted in NC up into December before. Just plant carefully – don’t fertilize or add a lot of soil amendments, because you don’t want to encourage the plants to break dormancy. For more tips, check out our article on planting trees and shrubs in late fall or winter. Good luck!
I live in Arizona, its Dec 2013.
I have made the mistake in the past to STOP the drip system in the winter because when we get a ‘cold blast’ it freezes up everything. Problem is, our plants and trees suffer because of it.
This year I have decided to water everything for 1 hour every 5 days. Well, we are about to get another cold blast tonight, but tomorrow, is my 5th day to water. We are ‘supposed’ to get rain. So its kinda of a sticky situation right now.
With all that said–the above was good advice, and I thank you for it.
I planted a small Norway spruce this fall in central Vermont. It has a screen fence around it to save it from deer. I am concerned about its survival this winter. Should I cover it with leaves and pine straw? We are snow birds so it will be watered only occasionally. Should it be watered if there is snow?
Saratoga County, New York. In July we added a new walk and garden beds. We used boxwoods for our foundation shrubs. The temperatures are going to be dropping into the high 20s at the end of the week and again next week; we may even have snow. Would it be good to water all of the shrubs now; there is only a 30% chance of rain on Wednesday. Also, should I wrap the boxwoods in burlap to protect them from the cold winter air. The front of the house has a north west (more west than north) exposure .
We live in central Florida, we get frost sometimes early morning during January and February so what I do set the sprinkles an hour before the frost hit the ground and keep up watering for several hours and this method is working with me to protect my trees and garden. I hope it will work for me to night.
I live in Jax, FLa and I don’t know if I should water the lawn before or after a hard freeze because I’m on the water. So the winds are stronger. THanks for your help!!
Here in the Mesilla Valley in southern New Mexico, we don’t get hard freezes very often, but when we do, (Feb. 2011), they can be devastating to our crops and trees. I’ve used this method for years and rarely do I lose potted or in-ground plants to freezing temperatures. I’ve been called crazy for watering before a freeze, but it works! Thanks Julie for this article.
Thanks. Your info has helped me save 25 year old phillies and a large ficus, as old. To big to move indoors but saved through the last snow. Going to water in the morning before the next freeze hits after the 1st. Thanks again. All plants were hospital gifts for a little handicapped girl who is now 30. Thanks again. We love our plants, as does everyone else, THANKS!#!
Should I cover plants while it’s raining cause we got a storm coming and a freeze tonight and all my plants are coming up
Should I cover plants while it’s raining cause we got a storm coming and a freeze tonight and all my plants are coming up. I live in Tennessee and it’s April
Thank you so much for all of your information we would have never known