Avoid watering when temperatures are below 40°F or when sustained freezing temperatures are expected within 24 hours as this water will freeze and not be available to the plants.
In cold weather, water should be trickled slowly into the soil. Water only when air temperatures are above 40 degrees F. Apply water at mid-day so there is time to soak in before possible freezing at night.
I did some research and found out that houseplants need to be taken indoors before overnight temperatures dip below 45 degrees. Most tropical plants suffer harm from temperatures below 40 degrees. Well, we have temperatures forecast to dip into the 40s again on Thursday and lower 40s on Friday.
When Should You Cover Plants? Cover your plants at night and remove them during the day when the temperatures rise above 32 degrees F, so that the soil can warm up again. Some outdoor plants won't survive the harsh conditions of winter, bring them inside and use these tips for caring for them through winter.
Cover Plants – Protect plants from all but the hardest freeze (28°F for five hours) by covering them with sheets, towels, blankets, cardboard or a tarp. You can also invert baskets, coolers or any container with a solid bottom over plants. Cover plants before dark to trap warmer air.
As a rule of thumb, water when the soil is dry to the touch, the temperature is not below 40 degrees F. (4 C.) and, if possible, when the wind isn't blowing. Drying winds may carry off much of the water you're trying to apply to the roots of your beloved plants.
You'll be able to tell when your garden is suffering after a cold snap. Leaves will curl, drop, or change color — usually from a green to a white, yellow, black, or brown.
Plants may need covering if there's a long period of 25-degree weather, but they probably can survive a very short-lived cold snap during the night, Reeves said. Calm nights are actually harder on plants than nights with light winds.
Most houseplants are tropical plants that can safely grow in a heated home during the winter. They will never survive outdoors in winter unless you live where the temperature stays at least above 50 degrees. In northern zones 4 and 5, plants need to survive months of below freezing weather every winter.
Thoroughly Water plants if it's not going to rain before the freezing temperatures arrive. It may sound illogical. However, a moist ground stays warmer than dry soil. Watering the night before the freeze comes will insulate the root structure of the grass and plants and decreases the potential for cold injury.
The optimum temperature for roots to absorb water and nutrients is around 68°F. At that temperature, the water in the substrate still contains a lot of oxygen, and it is also exactly the right temperature to trigger the pump mechanism in the roots.
It can be tricky choosing when is the best time to water plants in winter. Avoid watering early in the morning or late at night, keeping to the middle of the day wherever possible as the soil around plants should be dry at night.
Despite the fact your plants are dormant and brown, they should still be watered periodically. Plants that remain dehydrated in winter months often don't survive until spring. Not only does this create extra landscaping costs in warmer months, it can actually damage your plumbing.
It might sound counterintuitive, but most indoor plants need less water during the winter. While it's true that winter air is drier, plants experience a slower rate of growth during colder months; some even go completely dormant. Therefore, plants need less water to keep hydrated, and overwatering can lead to root rot.
There is less light in Winter and the temperature is cooler. This means the plant slows down because photosynthesis is less effective. Providing the room isn't excessively hot, you may reduce watering to just once every two weeks or once a month for some plants over the Winter months.
Semi-hardy cool-season crops (beets, carrots, Swiss chard, lettuce, cauliflower, potatoes, parsley) grow in minimum daytime temperatures of 40 degrees and higher. They cannot withstand hard frost without some kind of covering or protection.
Light freeze - 29° to 32° Fahrenheit will kill tender plants. Moderate freeze - 25° to 28° Fahrenheit is widely destructive to most vegetation. Severe or hard freeze - 25° Fahrenheit and colder causes heavy damage to most plants.
It is best to water in the afternoon or evening the day after a freeze so plants have had a chance to slowly raise their temperature. After a freeze, soft-stemmed, non-woody plants such as impatiens, cannas, elephant ears, agapanthus, amaryllis, begonias, philodendron and gingers may be pruned back to living tissue.
If you're wondering at what temperature threshold you should be bringing your plants, there's a short answer: when nighttime temperatures reach 45 degrees (F), it's time to bring your plants indoors.
Leaves and tender shoots subjected to freezing temperatures or chilling damage appear water-soaked and wilted. These tissues will usually turn black within a few hours or days. The tips of narrow-leaved evergreens, such as junipers, may turn uniformly brown.
A few hours may not be fatal, depending on the plant species, while 12-24 hours or longer is likely to kill the same plants outright. One way to tell is to remove the pot. Healthy roots are firm and white, while those killed by cold are brown and mushy.
Ice cold water will cause root shock, which may lead to permanent root damage, leaf drop and other problems. Allow the water to warm to room temperature before watering the plants.
Most houseplants are tropicals and prefer temperatures between 65-75°F during the day and about 10 degrees cooler at night. For many plants, temperatures below 50°F can cause problems.
The best time to water plants is in the morning or evening.
More importantly, watering at these times actually helps the plant retain water. If you water in the afternoon, especially during summer, the heat and sun are at their peak and the plant's water will evaporate instead of absorbing into the soil and roots.