WATER YOUR TREES (and Shrubs and Perennials) 

by Louise Conner, HAS Trustee

Photo by Karolina Grabowska on

 We can’t stress enough the need to water trees and shrubs when we’ve had so little snow this winter. The following information is from CPR News ( Focus on the most vulnerable trees, Jim Klett, a horticulturist at Colorado State University, said not all trees face the same threat from drought and dry weather. Any trees planted within the last three years should be first in line for the hose, according to Klett. Evergreen trees should be watered next since their needles continue to demand water over the winter. “With all the foliage on them, they’re going to desiccate and dry out very quickly. So evergreens are even more critical than deciduous trees,” he said. Finally, he recommends watering any trees with shallow root systems like birches, maples, lindens, alders, hornbeams, dogwoods, willows and mountain ashes.Wait until the weather warms up. Klett advises only watering trees when temperatures rise above 40 degrees Fahrenheit. Mid-day watering will allow the moisture to soak into the roots before freezing temperatures at night. Provide the right amount of water. Pay attention to the thickness of the trunk. When trying to figure out how much to water, Klett said to apply 10 gallons of water for every inch of trunk diameter. For example, a 3-inch tree would get about 30 gallons about every three weeks. It’s a mistake to pour all the water directly against the base of the trunk, Klett said. Instead, he recommends watering along the “drip line,” which is the area beneath a tree’s farthest-reaching branches. “You probably want to water there, because that’s where most of the feeder roots are for the tree,” he said. Mulch it good! Klett recommends applying mulch around trees to conserve soil moisture. If the ground gets dry enough to crack, the extra layer can also help protect tree roots from cold, dry air.
  Watering Shrubs and Perennials Much of this information comes from the Colorado Extension Service Fact Sheet: Water when the temperature is 40 degrees or above. Water in mid-day so that water has a chance to soak into the ground before the temperature drops below freezing.

Photo by Chris F on

Echinaceas Offer Easy Care Garden Beauty

by Diane Engles

Echinacea — bless you!  It does sort of sound like a sneeze, but Echinacea or coneflower routinely blesses our gardens with an easy to grow and hardy group of flowering perennials.  Echinacea has a long bloom season, is hardy, drought resistant, and is a pollinator magnet. If seed heads are left on, they will provide seeds for birds in fall and winter; goldfinches in particular love them. Echinaceas are also excellent cut flowers. Deer and other grazing animals will eat the young Echinacea plants but normally avoid mature plants, unless they are desperate.

Coneflowers are in the aster family and related to daises, asters, chrysanthemums, zinnias, and other members of this large family. There are nine species of coneflowers native to eastern and central North America. The most popular garden coneflower is the eastern purple coneflower (Echinacea purpurea). Others in the genus are narrow-leaf coneflower (Echinacea angustifolia), pale purple coneflower (Echinacea pallida), Tennessee coneflower (Echinacea tennesseensis) and  yellow coneflower (Echinacea paradoxa). All are deciduous herbaceous perennials, and all have a taproot except for Echinacea purpurea. They form a slowly expanding clump that may be divided every few years to maintain vigor.

The wild-type echinaceas are typically 2 ft wide and 3-4 ft tall. Modern hybrids have been selected for smaller stature with some as small as 1 ft high. In the wild, a single plant can live up to 40 years. In the garden, they are best when divided every 4 years. Most are hardy to at least Zone 4. They prefer full sun but can tolerate a little shade; too much will make them leggy and prone to flop over. Coneflowers are not picky about soil type but don’t tolerate wet or mucky conditions.

Echinacea also has medicinal uses, primarily derived from Echinacea purpurea and Echinacea angustifolia. Native American Great Plains tribes have used Echinacea as a cure-all for over 400 years. These Native Americans introduced European settlers to the plant and they used it to treat many diseases including diphtheria and scarlet fever. Echinacea was once the most widely used plant remedy in the U.S. and Europe until the dawn of the pharmaceutical age when it fell out of favor. Over the last couple of decades, echinacea has once again become a popular herbal remedy.  It is thought to boost the immune system to help fight off illness such as colds, flu and infections although scientific studies have had mixed results.

Photo by Chait Goli on

In the HAS Gardens: Evergreens

Article by Diane Brunjes, HAS Gardener, published in February 2020 HAS Announcements

Living in a northern climate as we do, makes one appreciate anything that brings color and life to the garden in the winter. And there seems to be nothing that does that better than conifers. Strictly speaking, the ones we are referring to are evergreens. There are however, conifers that are NOT evergreens, like larches (Larix), the bald-cypress (Taxodium) and the dawn redwood (Metasequoia), which all lose their needles for the winter. But the ones we will focus on now are the ones that retain their needles over the winter – hence, ever-green.

Many gardening experts and designers say that your garden should be composed of approximately 30% evergreens. This figure can be adjusted to suit your tastes, but how many of us can claim that we get anywhere near that percentage? But considering that most of the garden is D-O-N-E by late October, and really doesn’t get going again until April, that leaves at least five full months of drab – unless you plan and plant carefully.

Of course, many perennials bring winter interest, like sedums, opuntias, grasses, agaves, penstemons with its evergreen foliage, hellebores, coneflower seedheads, and artemisias are just a few of the flowering herbaceous plants that we can rely on for winter interest. At least, until that two-foot snowstorm with 40 mile-an-hour winds occurs, and then most of our interest is plowed under until the next growing season.

That’s why adding evergreens to your garden can be the year-round boost that you might be looking for without realizing it. One of the evergreens we will be adding to the sensory garden this year is Pinus nigra ‘Bambino’. The name alone is enough reason to grow it, but its dwarf nature and tight branching certainly are other reasons. Forming a low wide dome over many years, this evergreen eventually becomes so dense, that reaching in with a gloved hand every two or three years becomes necessary to clean out the accumulation of fallen needles. Although it looks very “pet-able”, the needles retain the stiffness of the Austrian pine, and if you do clean, do it carefully. Look for it in the HAS Gardens this spring.

Another evergreen we are excited to be adding is the very narrow exclamation point Juniperus scopulurum ‘Blue Arrow’. A selection of our native Rocky Mountain juniper, this is even narrower and slightly smaller than J. ‘Skyrocket’. Its new growth tends to be slightly bluer, but this varies per specimen, as we have seen some that definitely trend more towards green. We will be adding three of these in the Demo Garden. This kind of exclamation point has several design functions. In one spot it will “stop” the eye, in another, it will be simply a backdrop to other features, and in a third spot, it will be that exclamation mark that is so useful in the garden if not overused. In ten years, these junipers will be 12-15 ft tall x 2 ft wide.

If you are looking for design inspiration for your own garden, be sure to google The Bressingham Gardens in Norfolk, England. Some conifer gardens can feel heavy and even a bit oppressive, but Adrian Bloom makes amazing use of grasses, vibrant-stemmed dogwoods, and deciduous plants to bring lightness and movement to his garden. Be warned, though, if you watch the video on their website, you will think it is just a perennial garden! Bloom used to use, very heavily, heaths and heathers (which we can’t grow) but in the last decade has begun to move to the above-mentioned groupings. This has horrified some conifer garden purists, but makes a very welcome change, we believe, for everyone else.

Happy Gardening, and as always, come visit the Gardens!