_As fall turns to winter, many gardeners enter hibernation mode. The garden colors have faded, annuals have died, and perennials are muted in dormancy. With gardens quiet and at rest, it's easy for a gardener to enter the same pattern. This relaxation and lack of action can have a devastating effect on plants.

Many tree, grass, shrub, and perennial roots remain viable during cold weather. That means they still need water. In many regions snow fall and occasional rain are enough to provide adequate moisture but during and after prolonged bouts of dry weather or drought it's possible and likely that soil can dry out and the roots will be damaged. Any plant with a shallow root system is at threat and supplemental watering becomes a requirement if you want your plants to survive winter.

_Lawns can be particularly susceptible to winter kill, the damage or death of plants in winter. Most cool season grasses can handle cold temperatures and snow cover, but when they encounter desiccating winds and sustained warm winter temperatures, dormant or semi-dormant turf grass can be injured and killed.

Newly-planted trees and shrubs are also susceptible to injury in the same weather conditions. They typically require more water than established plants until their root systems become strong enough to sustain them, a period that takes one to two years, and dry winter conditions can be deadly.

Perennials, particularly new transplants, that are exposed to winds and full sun can quickly dry out. Potted perennials are especially at risk.

_Watering in late fall, winter, and early spring should be a regular part of your gardening activities. Heavy snowfall mitigates the need, but watering may still be necessary. Snow in cold weather actually holds less moisture than commonly believed. Ten inches of snow at the peak of winter only holds about one inch of water. If your storms drop an inch or two of snow, there is hardly any moisture present and when brief snows are followed by long periods with no snow plants are effectively exposed to desert conditions.

Not every day is a good watering day, even if plants need it. You should only water when the outside air temperature is above 40F degrees (4C). The soil should not be frozen or covered with snow.
 
Also, try to water around noon. The air is above freezing and that will allow the water time to soak into the soil and avoid the possibility of freezing into an ice layer at night. Compacted soil, typical in many lawns, may need a second watering to ensure water soaks into the soil without running off.

Watering by hand is usually the best method. Soaker hoses and drip systems may be good during the warm season but in winter any residual water can freeze quickly, thaw slowly, and render them ineffective. A sprinkler on a hose works well for lawns, but be sure that the hose is completely drained after use or you'll encounter the same problem when you reach for it again.

Look closely at your landscape to identify areas that need supplemental winter water. Areas with south-facing walls can dry out quickly due to reflective heat. Snow can remain under the shade of a tree, but the roots can extend well beyond that into dry zones. High spots can receive more sun and wind and be the first to dry. Note where the snow melts first and that will probably be the same spot that needs extra water first. Mulched plants may need less water but when the soil is dry beneath the mulch watering is needed.

Generally, trees need about ten gallons (38 liters) for each inch (2.5 cm) diameter of the trunk. That means a four-inch thick (10 cm) tree requires forty gallons (150 liters) of water. Thankfully that amount only needs to be supplied once a month in winter; young trees may need two waterings. This amount ensures the water soaks in to the depth that the roots are growing in an area encompassing the drip zone. This is a total amount of water and can be reduced by the amount of snow or rain.

Small, established shrubs (less than three feet or one meter) require about five gallons (19 liters) of water per month. The amount increases to about 18 gallons (68 liters) to shrubs taller than six feet or two meters. Newly-planted shrubs need twice that amount.

Many established perennials can handle dry conditions for prolonged cold periods but when sustained warm winter days combine with dry weather, watering is advised. Potted plants will dry out faster and should be the first to receive supplemental water. The amount of water varies with the size of the plant so provide a good soaking once or twice a month. Plants that you put in the ground in fall will probably need at least twice that much.

_You don't have to water in winter. Many plants have naturally adapted to varying winter conditions. But your garden plants may not be native to your region and probably don't have those natural adaptations. If you choose to avoid winter watering you're also choosing to place those plants under stress that can cause damage and death.

I've talked with many people who find large patches of turf dead in the spring. Others wonder why so many of their flowers or shrubs don't survive the winter. All around town I see trees where only half is alive and growing. This can all be attributed to winter kill. Sure, I live in a region with harsh, dry winters, but the solution for me and so many others is supplemental watering.

It takes extra effort to pull the hose out on a cool day, spend the time to water each plant, thoroughly drain the hose afterward, and put it all away, but for the two or three times it may be necessary over the course of winter it can save countless hours later. Pruning unnecessarily dead and damaged branches, replacing flowers and sod, and removing dried-out bushes is work that few gardeners look forward to doing. A simple application of water when plants need it most, in winter, can be a life saver, literally.

Every year has its memorable weather events and this one isn't disappointing in that respect. From record snow to record tornadoes to record floods to record heat, the United States is going to long remember 2011. While many of these events affect different regions at different times, each of us has to deal with some type of weather adversity in our gardens on a regular basis.

A short while ago I was writing about drought and the effects of overly-dry conditions. Since then the monsoon season began early and rain became a common occurrence. Last week Colorado Springs set a new record for most rainfall in one day; 2.3 inches fell in the afternoon. Just when I was dealing with irrigation issues to try and keep my plants watered, I suddenly had to deal with drainage issues to try and keep my plants from drowning.

I'm always advocating steady observation in the garden. We like to garden in typical ways on typical days, but should take full advantage of extremes. Whether extremely dry or extremely wet, we should stop and pay attention to how our gardens and plants are reacting. When we are able to modify our actions effectively for the unique events, daily activities become downright easy.

My latest dilemma arose due to saturated soil. As part of my analysis of the soil in my vegetable garden, I realized I have an expansive layer of clay about a foot down. To overcome this problem I brought in a few truckloads of amended soil. That raised the surface level to offer plant roots more room to grow before encountering the clay. In dry conditions that solution works well but after days of torrential rain the upper soil is soaked and drainage becomes virtually nonexistent when the water hits the clay level.

In my numerous raised beds, I brought in new soil and amended it well. As I've described previously, compost and organic matter act as little sponges to absorb water and help keep the soil moist. That reduces the need for daily watering during dry days. During the monsoon season the excessive rain and vertical sides on the beds create a bathtub effect that can hold in the water and the organic sponges keep it there.

Soggy, saturated soil will kill plants in time. The key to dealing with that is to recognize it as a problem. On normal days, pooling water between my rows of plants isn't an issue because it will gradually seep into the soil and nourish roots. After successive days of rain, pooling water is a concern because if it remains above the surface for long periods of time that identifies the waterlogged state below the surface as extreme. The roots are drowning.

Regardless of how much time was spent designing channels and troughs to collect and divert water for dry days, it's now time to dig through the little dirt walls and allow the water to drain away from the garden. Once soil is saturated the only thing to do is to reduce the addition of more water.

Just as we can hold our breath for short periods when swimming underwater, plants can handle a brief period without oxygen. Sustained water exposure is deadly, but when you take efforts to cut that exposure you offer your plants a chance to take a breath, so to speak.

Eventually sun and wind will dry out the garden and things can return to normal. You can use that as part of your recovery plan. Mulch works very well to keep the soil surface from drying out. During extreme water events you may need to remove mulch to give the soil extra opportunity to dry. Expose as much surface area as possible to the air.

I use straw as a mulch in many areas. Extra straw in the low spots will absorb rain. If I pull out the soggy straw after a strong storm, I can at least keep that amount of water from adding to the drainage concerns.

If you cover your raised beds with plastic during cold weather, it may be time to bring the plastic back out and cover the beds during wet weather. Watch the forecast and put a lid on the bathtub to keep it from filling.

Identify points and places where the water pooling is worst. Just as a pot needs drainage holes, you may need to create drainage in areas of your garden you hadn't anticipated. Drilled holes in a raised bed, overflow hoses, and alternate water channels can divert excess water. You may be able to make some of those corrections during the rain storm and you may have to wait until the soil has dried afterward. Either way act to keep the problems from returning.

Some things should go without saying, but I'll say them anyway. If your irrigation is on an automatic timer turn it off after a day or two of excessive rain. You don't want to add to the problem by overlooking that. Before you begin watering again don't assume the roots are good because the surface is dry; make a physical check of the moisture level a few inches deep.

If you're planning a new bed in the future or redoing an old one and plan to bring in custom soil, opt for one that has a good sand component. Sand drains well and can help minimize drainage issues. Organic soil amendments are always a good idea and ensuring clay soil is amended well can improve its drainage.

We've had a few dry days and my garden has recovered. But there's a solid chance of more rain today and for the next few afternoons. I now have drainage channels, plastic ready to pull over the hoops on the raised beds, reduced mulch in some spots, and extra straw in others. I look forward to the rain because it cuts down on my need for supplemental watering and now I don't need to be as concerned about drowning my plants.

Portions of the United States are struggling from the impact of excessive rain and snow melt as others are dealing with the effects of long-term drought. For the people with houses under water, there may be minor envy of the dry regions, and for those of us living in the parched environs there is a whispered desire to have the worries of too much rain. The extremes of weather make comrades of the victims at each end of the spectrum.

The U.S Drought Monitor tracks the effects of prolonged periods without precipitation and shows the entire southern portion of the United States as suffering from at least "abnormally dry" conditions. Nearly the entire state of Texas is designated as "exceptional" drought, the highest level. Every week brings us new record temperatures. Yesterday Phoenix, Arizona, set a new record high of 118F degrees.

While we perspire and curse the heat, drought stress on plants, particularly trees, can be fatal (see my blog, "The Life of a Tree"). Trees need water to sustain their lives, like every living organism, but they have the ability to survive on energy and moisture reserves stored in their roots. Like camels and their humps, trees can survive fairly well without regular water, but only to a point. For survival, most landscape trees need supplemental water.

That means that you must water your trees when natural precipitation fails to deliver enough life-sustaining moisture. Many people think that occasional rain, even when far below normal, is enough to sustain trees. They remember the television science program where deserts came alive after a single downpour. While some desert plants are able to store vast amounts of moisture for long periods of time, the typical trees we have in our yards need regular irrigation and periodic light rains during a drought aren't enough.

As with most garden plants, begin by checking your soil. Dig random holes a few inches deep under the outermost branches of your trees. If the soil is retaining moisture, if you can form it into a ball that holds its shape, the roots will be able to absorb it and the tree is okay. If you have a soil moisture meter insert it at different levels. If the soil is dry at two inches, at three inches, and deeper, you need to water deeply.

Most tree roots are located in the upper six to 24 inches of soil. The shade tree in your backyard hasn't tapped into a deep water reserve with penetrating roots. It's trying to soak up the moisture in the top few inches of soil. The smaller feeder roots are the ones you encounter when you dig a hole for a new plant and they're the ones seeking water. If you encounter dry soil with a test hole, the tree is encountering the same dry soil.

The solution is deep watering. A tree requires gallons of water and bigger trees need more. Trees obtain water best when it soaks the soil to a depth of at least 12 inches. A general rule is 5 to 10 gallons of water per inch of tree diameter, per watering. A three-inch wide tree needs up to 30 gallons of water. You should water this deeply at least twice a month during drought when no other natural precipitation occurs.

The key difference in the amounts of water required are due to the individual needs of the tree. Some trees are more drought tolerant and can survive with less water, others need more water more often. Most Maple, Hawthorn, Goldenrain Tree, Coffee Tree, Juniper, Pine, and Oak trees can handle dry growing conditions.

How you water is important too. Drip lines next to the trunk don't work well. Watering within the dripline is good, but may not be enough. You have to look at the size of the tree and try to determine where the feeder roots are.
 
The roots of an established tree extend well past the confines of the branches. Normal root growth extends two to four times the diameter of the tree crown. A tree that is 15 feet wide at the top may have roots throughout a 30- to 60-feet circle. You can expect the root spread to be at least equal to the height of the tree. Under very dry conditions some trees can send roots out 10 times the crown diameter; there might be roots 100 feet away from large trees.

Younger trees have roots much closer to the trunk so watering with a soaker hose curled around it can be effective. Using a deep-root feeder needle attached to a hose, inserted about eight inches deep, may also work on young trees. But neither of these methods can adequately cover the root zone of a large, established tree.

Bigger trees need water throughout the span of their root zone. Oscillating sprinklers and impact rotors can broadcast water over larges areas. Think about the kind of sprinklers you see in parks and golf courses.

You'll need to determine how much water your hose and sprinkler put out. One easy way is to take a bucket and direct the sprinkler spray into it (yes, you'll probably get wet). Time how long it takes to fill the bucket. If a one gallon bucket fills in 30 seconds, then your hose and sprinkler are distributing two gallons per minute. If you use that sprinkler to cover a tree's root zone, you can expect about 30 gallons in 15 minutes.

That's the first part of watering. Soil is always key. You still need to be sure the water is soaking the soil. So after you've moved the sprinkler to a new location, and after you've let any puddles on the surface drain, go back to your test hole and see if water is making it down to the level of the roots. If you find only the top inch or two is wet while it's dry below that, you will need to water for a longer period of time even if the math says you've distributed the appropriate number of gallons. If the soil is wet at six inches it should fine below that.

After you've figured out how much water your sprinkler puts out and how effectively the soil absorbs it, you can set up a schedule of regular watering at two or three week intervals. Much depends on the weather. If you've had no rain, water more often. If thunderstorms and rainstorms start occurring, you may not need supplemental water at all. Check your soil's moisture content to be sure.

Another consideration is the tree's location. If a tree is near a lawn that is on a regular irrigation cycle, the roots on that side of the tree are soaking up moisture under the grass. You should account for that and may only need to do a partial watering on the tree's dry side. Trees surrounded by turf may not need additional water at all, even in drought.

You take the time to water your vegetable garden, your flowers, and your lawn. Remember the trees. A drought can be devastating and with trees you may not see the impact for two or three years. If you wait for stress indications, it will be too late. If it's dry now, water now. Your trees will appreciate it.