Winter Watering on the Front Range
Our often dry, windy winters here on the Front Range can be especially tough on landscaping plants such as perennials, trees, shrubs, and lawns. Most plants need moisture throughout the winter to prevent root damage, so developing a winter watering schedule can help to protect your landscaping.
If roots are damaged over the winter, the “winter kill” is not obvious until summer. A plant or lawn may green up nicely in the spring, but in the first hot days of summer, a plant with damaged roots will struggle to take up enough water. This affects the health of the entire plant and can result in the browning of foliage (especially in evergreens and lawns). A weakened plant is more susceptible to pest and disease damage, and in severe cases, the entire plant may die from winter kill. Because our winters often lack consistent precipitation, many plants will benefit from supplemental winter watering.
What plants benefit from winter watering?
Nearly all plants will benefit from winter watering. However, the following plants are especially sensitive to drought injury throughout the winter.
- Recent Transplants
- Plants that are less established have smaller root systems and need more supplemental water to thrive.
- According to Colorado State University Extension, trees take one year to establish for each inch of trunk diameter at planting.
- Bare root plants take longer to establish than container plants.
- Plants transplanted later in the season take longer to establish.
- Because evergreens retain their needles, they still transpire throughout the winter. Without adequate soil moisture to replace this water loss, evergreens are at a higher risk for winter burn.
- Evergreens at highest risk include arborvitae, boxwood, fir, Manhattan euonymus, non-native pines, Oregon grape-holly, spruce, and yew.
- To help limit desiccation, some evergreens can be treated with a product such as Wilt Pruf® or Bonide Wilt-Stop®. Read the product label for uses and instructions.
- Deciduous Trees and Shrubs with shallow root systems
- Woody plants with shallow root systems are more likely to dry out because they cannot pull water from deep in the ground.
- These include alders, European white and paper birches, dogwoods, hornbeams, lindens, mountain ashes, willows and several varieties of maple including Norway, silver, red, Rocky Mountain, and hybrid maples.
- Herbaceous Perennials and Ground Covers
- Even established perennials and ground covers can suffer from winter kill, especially those without wind protection and those with south or west exposures that experience more freezing and thawing.
- Newly established lawns are especially at risk for winter kill as well as those with south or west exposures.
When should I winter water?
Most plants will benefit from winter watering from October through March.
According to Colorado State University Extension, water one to two times per month during dry periods without snow cover. Windy or sunny sites (those with south or west exposures) dry out quicker and will require more water.
Only water when air temperatures are above 40°F and the soil is not frozen or covered in snow.
Water mid-day or earlier to ensure the water has time to fully soak in before freezing at night. Test soil moisture before watering by inserting a probe or screwdriver into the soil. If the screwdriver goes in easily, watering is not necessary. However, if it is difficult to push the screwdriver in after a few inches, watering is necessary.
What is the best way to apply water during winter?
While water can be applied by hand, typically it is most efficient to water with a soaker hose, drip hose or sprinkler that attaches to a hose. (Do not use an in-ground sprinkler system as these should stay winterized until spring.)
Trees can also be watered using a deep-root fork or needle that is inserted no deeper than eight inches into the soil in multiple locations throughout the dripline and outside of it. As with watering in the summer, it is important to allow water to slowly soak into the soil. This results in deeper penetration and prevents runoff. For trees, water should penetrate to a depth of 12 inches.
How much water do my plants need?
Mulch is crucial to helping soil retain moisture. The following recommendations assume that all plants have at least two inches of mulch. Keep in mind that most sprinklers deliver approximately 2 gallons of water per minute.
- Apply at least 10 gallons of water for each diameter inch of the tree
- Water once a month (twice a month for newly planted trees)
- Water from the edge of the branches halfway to the trunk, and then two to three times that distance from the edge of the branches outward
- Newly Planted: Apply at least 5 gallons of water twice a month
- Small, established (less than 3 feet tall): Apply at least 3 gallons of water once a month
- Large, established (more than 6 feet tall): Apply at least 10 gallons of water once a month
- Water within the dripline and around the base
- Water requirements vary based on level of establishment and size of the plant
- As a general guideline, apply half the amount of water that would be applied in a typical summer watering session once a month
- Water lawns if there has been no precipitation for three weeks and the lawn has a south or west exposure
- Apply half the amount of water that would be applied in a typical summer watering session
Fall Perennial Planting
Planting in the fall can save you a lot of money while also giving plants a jump start next spring! Plants that establish strong roots during the fall will come back bigger and stronger in the spring time.
However, fall planting requires careful consideration and attention to detail from the gardener. The trick is to give fall plantings a little extra care to help them get established before the really cold weather sets in.
Here are four things you can do to help your plants get established:
At the time of planting, be sure to use an inoculant specifically formulated for perennials, trees and shrubs. These products will help the plant to start establishing roots before all of the foliage dies back. We recommend using an inoculant over a root stimulator this late in the season so you can avoid giving any extra nitrogen to the plant before it goes in to dormancy.
Mulch helps to retain soil moisture while also protecting roots from sudden changes in temperature. We recommend using 3″ of a good quality mulch to keep plants protected. Make sure that mulch does not contact the bark of woody perennials.
Protect Plants from Early Freezes
Keep an eye on the weather and cover the plants when the temperatures dip below freezing throughout September and October. This is most important for perennials. Trees do not need to be blanketed, but bark wrap should be used on all young trees to protect the trunks from splitting during our freezing and thawing cycles. When covering perennials, use heavy fabric or plastic and prop it up so that it is close to, but does not touch the plant (Plastic that touches the plant during a freeze can actually do more damage.) Be sure the covering goes all the way to the ground and cover the edges with soil or mulch so that it will trap heat from the soil.
To support adequate root growth, plants will need to be watered regularly in the fall. Keep your soil evenly moist, but not soggy, through the fall time. Remember to monitor your plants regularly! A plant that crisps up due to lack of water in the fall time is not likely to survive the winter. When the plant goes dormant, they will require less frequent watering, but will also need to be watered throughout the winter. Remember that desiccation is the result of cold weather plus dry soil. For more details on winter watering, visit our Blog.
Forcing Paperwhite Narcissus BulbsFlowering bulbs can be forced to bloom indoors, creating a beautiful display of color and fragrance even on the coldest days of winter. Some bulbs require a period of cold treatment to bloom, which can be a little tricky. If you’re new to forcing bulbs, we recommend starting with Paperwhite Narcissus. Paperwhite bulbs do not require a cold treatment and are super easy to bloom in water. Planting – A Simple Hydroponic Method
- Find a decorative bowl or dish that is 3 to 4 inches deep and holds water
- Fill the dish with about 2 to 3 inches of clean decorative rock, pebbles, pea gravel, perlite, or other very porous substrate leaving about 1 inch of head space at the top of the dish
- Add water until it is just slightly below the surface of the rock
- Set the bulbs on top of the rock with the basal plate (root end) facing down
- Use a little more gravel to cover the bottom quarter of the bulb
- Keep the water level just at the level of the basal plate (too much water will cause the bulb to rot)
- Bulbs typically do best if they are kept in a cooler location (50 to 60 degrees F) in low light for the first 2 to 3 weeks
- Once the bulbs are rooted and shoots appear, bring into direct sunlight and warmer temperatures
- When the flower buds begin to show their color, move the plants into indirect sunlight to prolong the flowers
- Plant new pots every two weeks starting in mid-October to have blooms from Thanksgiving into March.
- Keep bulbs out of reach of pets and children as these plants are toxic if ingested.
- Forced paperwhites will not likely rebloom, so it is best to toss out spent bulbs.
Growing Garlic in the Pikes Peak Region
- Garlic cloves are best planted between November and April, although you will generally get a bigger and better crop if you plant in the autumn. If planted between October 1 and November 15, the clove will have a chance to develop some roots before it goes dormant for the winter. Here at Rick’s, we think the ideal time to plant is at the end of October.
- Separate cloves from the bulb and plant root side down (pointed side up) about 2-4 inches deep, 6-8 inches apart in the row and 12-18 inches between rows. A bulb planter used for tulips and daffodils is an excellent tool to get several cloves planted quickly.
- Mulching 6-12 inches of straw or mulch in mid to late November, when the ground begins to freeze, will ensure the garlic will survive the cold temperatures.
- In early spring as the ground thaws, look for the green tips beginning to emerge underneath the you mulch.
- Fertilize in spring with a complete fertilizer such as 10-10-10 (3 lb per 100 sq. feet), or an organic complete fertilizer at roughly twice the rate, as usually they contain roughly half the nitrogen as chemical fertilizers.
- As half of the leaves begin to die-back in July, harvest the garlic by gently pulling on the stalk while prying beneath the bulb with a trowel. The clove you planted last fall will have turned into a multi-cloved bulb. Gently shake off the dirt but do not wash before storage. Don’t wait until all the leaves have died-back or your bulbs will not store well.
- Cure the garlic by hanging in a warm, dry, well ventilated place.
- Give the bulbs another shake after two weeks of curing to remove more soil, cut off the stalks of hardneck varieties and store them in a cool, dry place. For softneck varieties, you can leave the stalks attached if you wish to braid and hang them for ease of use and aesthetics in the kitchen – but you may also cut off the stalks and store them with the hardneck varieties.
- Save some of your biggest bulbs for planting next fall.