Don’t Be Afraid To Prune Perennials

One of my favorite spring chores is pruning ornamental bushes and shrubs to get them ready for vigorous spring growth. I’ll throw in the caveat that pruning wild rose bushes is not a favorite chore. Even with special gloves made for rose pruning, I manage to stab myself around my upper arm, legs and shoulders. These are some pretty big bushes!

My husband and I have different philosophies on how to prune. He tends to cut a lot of the plant, but does a great job of shaping trees. I tend to underprune and some of the bushes look leggy, with too little growth on the lower portions of the branches. So we try to temper each others’ approaches.

spring blooms in xeric garden
Spring means the apple tree along the river (background) blooms big. It also means time to prune. The green plant in the left foreground was almost as tall as the red bud to the right only a few weeks before.

The best approach, especially in xeric gardens, is to follow the plant’s natural growth pattern. This means avoiding the “haircut” prune, or cutting a plant straight across the top. It’s like topping trees; it makes me crazy. A haircut prune on a bush forces new growth only along the top of the plant.

For deciduous shrubs (those that lose leaves in winter and come back in spring), pruning should include thinning to make sure sun reaches bottom branches and to prevent crossing or rubbing of branches. Gradual renewal pruning involves removing dead and old branches just above ground level each year. You also can trim to shape long branches.

Rejuvenate old plants by cutting up to one-third of the oldest and tallest branches just at or above ground level before new growth starts. Here’s the thing, though: Although experts generally warn against pruning an entire plant all the way to the ground, I have done that for several established woody plants that get long and leggy and have few flowers. I’ll even do it annually with great success.

For example, I trim Russian sages (Perovskia atriplicifolia) to just a few inches above the ground, or just above new growth, each spring and they love it. We had a hibiscus (I’m not sure of the variety, but see below) that we pruned to the ground each fall to help it winter over in Albuquerque. It came back in the spring, with huge, maroon-colored blooms that would cause people to stop on their walks and comment.

hibiscus-pruned-nm-landscape
We trimmed this hibiscus, the plant with the large, deep read blooms, to the ground in the fall to protect it from frost and to produce foliage and blooms.
hibiscus-flower
The hibiscus blooms were beautiful and continuous from mid-summer to early fall.

 

Finally, I trimmed an old and overgrown butterfly bush (Buddleia davidii) to just above the ground last year, and by the end of summer, it was more than six feet tall and full of deep purple blooms, butterflies and hummingbirds.

Butterfly bush trimmed back
Butterfly bush (the woody plant in the back of the first bed) cut back last year nearly to the gtound.

 

Butterfly bush after hard pruning
Here’s the same bush in September from the other side. It’s happy, and so are the hummingbirds and butterflies.

Every plant differs in just how much to prune and when to prune it. For example, most of our xeric plants enjoy a cut in early spring. I wait until I see a little new growth appearing and then bring out my pruning shears. But we have a few forsythia bushes, which bloom early, but should be pruned after they bloom. And most evergreen shrubs need only some thinning.

Be sure to use clean bypass pruners and loppers on your plants, and clean after each use, especially if you cut any diseased branches.

Plant Select 2015 Plants for High-Altitude Gardens

I’ve written before about how the harsh environment of the high desert and foothills of the Rocky Mountains affects plants. But I’ve got good news! The brilliant folks at Plant Select,have announced their new plants and recommendations for 2015. Plant Select is a nonprofit source of plant selections that thrive in the High Plains and Intermountain regions and in a range of conditions, including low water. I’ve summarized a few of my favorites:

Coral baby penstemon (Penstemon x “Coral baby”). This is a new plant with upright spikes of coral-pink flowers that bloom from May through July in Zones 5 – 8. It takes moderate to dry water conditions once established and prefers sandy, well-drained soil. I love to see hummingbirds on penstenoms. Plant Select says Coral baby also attracts bees and butterflies. The plant was selected by breeder Kelly Grummons of Denver, who specializes in xeric plants.

 

Coral baby penstemon, a new introduction from Plant Select for 2015.
Plant Select’s 2015 Coral baby penstemon for Zones 5 to 8. Image courtesy of Pat Hayward, Plant Select.

WINDWALKER royal red salvia (Salvia darcyi x S. microphylla). I like that this hummingbird attracter is deer resistant. Plant Select says that it produces blood-red blooms from June through October in Zones 5 to 9. Cutting the salvia back in early summer can reduce its height (which can reach up to 58 inches). WINDWALKER salvia likes full sun and is moderate to xeric in water needs. It’s also from Kelly Grummons of Denver.

Plant Select's new WINDWALKER Royal red salvia is a moderate to xeric beauty.
Plant Select’s WINDWALKER Royal red salvia, a new plant for 2015 that produces blood-red blooms all summer.

WINDWALKER big bluestem (Andropogon gerardii “P002S” grass. This new introduction from Plant Select for 2015. Bluestem grass is one of the most beautiful ornamental grasses, and grasses can make a great statement in a xeric landscape. I especially love them near walkways or up against rocks. The powdery blue foliage on the WINDWALKER big bluestem can grow up to 6 feet tall in Zones 5 to 8. We left our bluestem through fall and enjoyed the dried foliage in the winter wind, then cut it back to the ground in early spring. It grew back, but was not as hardy the next year. This variety was selected by Sunscapes Nursery, and should reward with purple plumes in fall. It should get by with moderate water or dry conditions.

Windwalker big bluestem from Plant Select, a new grass for 2015 that's perfect for a xeric garden.
Plant Select’s new introduction WINDWALKER big bluestem grass is a perfect choice for a breezy xeric garden. Image courtesy of Scott Skogerboe and Plant Select.

Engelmann’s daisy (Engelmannia peristenia). This is one of several recommended plants from Plant Select for 2015. Because it’s native, it should adapt to high desert climates and water conditions. These grow wild at our place and when we head out to mow down weeds, we try to mow around them. They grow about 2 feet tall and are filled with yellow daisy blooms in late summer that attract pollinators. In the garden, plant them in part shade to full sun in Zones 5 through 10.

Engelmann's daisy, a native wildflower of the Southern Great Plains, is among the 2015  Plant Select recommendations. Image courtesy of Pat Hayward and Plant Select.
Engelmann’s daisy, one of Plant Select’s recommended plants for 2015 because of its adaptability to all sorts of conditions.

Visit Plant Select to learn more about their selection process and 2015 recommendations. I’ll probably include a few more in future posts. And if you live in the high desert or intermountain West, ask your local nursery if they stock any of the Plant Select recommendations.

How To Read Plant Label Codes for Watering Needs

Plant tags, labels and catalogs are much more attractive if they use icons instead of text instructions. Much like infographics, it’s a newer direction in communication. I see the good side of it, especially for people who have low literacy or shop with small children and don’t have time to turn the tag around for more information. I could say the drawback is that the more we put in symbols, the less we need writers, but that’s not a rant for this blog post.

As far as I know, water symbols are not standardized. If I’m wrong, I would love to be corrected. I think a standard nomenclature and symbol system for plant watering would be a great service to gardeners.

plant-catalogs-labels
Catalogs, seed packets and plant labels use a variety of methods to give us clues about a plant’s water needs.

Most water requirements are represented by a water droplet symbol that’s empty, partially filled or completely filled. My summary of similar legends, like the one used by the Albuquerque/Bernalillo County Water Authority, provides the following clues to irrigation:

Empty drop: A plant that requires only rainwater or no supplemental watering once established. So be sure to give a new or transplanted tree or bush extra water until it appears healthy. This can be up to a year for trees and some bushes. After that, there’s no need to irrigate the low-water plant at all. Half-filled drop: This is a medium-water plant. It will always need some supplemental water, depending on what Mother Nature delivers. Most medium-water plants need supplemental water once or twice a month during the hottest days of summer.

seed-packet-water-drop
This seed packet shows the moderate water needs of a sunflower.

Full drop: I am not familiar with these plants. Seriously, they usually aren’t going to make it in places that deliver little rainfall, and if they do, it’s not water-wise gardening. But they often can survive in the right climates and conditions, maybe in a welled spot or container, or where there’s run-off from a streambed. Of course, if you live in a tropical area, that’s just not fair. There are additional variations on these labels, like partially filled drops. I’ve also seen use of watering pails as symbols. Most add text alongside the icons, but if in doubt, ask for help from the nursery staff or a local master gardener.

portulaca-bloom
And because I have to include a pretty flower picture, here’s a portulaca bloom. I love these low-water heat lovers.

No matter what the label shows, circumstances can affect water needs, so don’t take your water icon at face value! Aside from plant establishment, wind and unexpected heat waves can dry plants out. Summer monsoons can nearly drown our drought-resistant plants! And welling and mulching around plants helps them retain water, maybe helping you push a half-filled drop to a quarter-filled one…

Four low-water Container Plants

I love pots! Actually, I love any kind of container that will hold a plant. We’ve been known to grow herbs in a claw-foot tub and annuals in an old washer. When you grow plants in containers, you increase your flexibility – you can move the container with the sun (maybe not the claw-foot tub so much…) and have color in a shady location by your front door. You also can practice “flower arranger,” creating a few new containers with each season’s annuals, or putting together a group of perennials you can keep outside all year or winter over.

Here are a few favorite low-water plants that grow well in containers:

Verbena (Verbena tenuisecta). Verbena species vary, but the warm-zone, low-water species can grow with very little water. They came up through the gravel pathways in our rock garden, re-seeding from previous years. I’ve planted small varieties of red, white and rich purple verbena in containers. Once established, verbena will spread and using it in container groupings helps tie them together or add pops of color. Verbena requires no deadheading, though removing spent flowers can prolong the bloom period, which usually runs from spring through frost, depending on your zone.

purple verbena
Verbena looks great alone or as part of a group planting. This magelana violet variety, and the photo, is courtesy of PlantSelect.

Chocolate flower (Berlaniera lyrata). Great in a rock garden or container, a chocolate flower always pleases. And in case you’re wondering, it really does smell like chocolate. I ought to know. Anyway, chocolate flower is a wildflower that produces delicate, daisy-like flowers with a light, almost red, center. Its leaves are a pale, almost silvery green. It’s extremely drought tolerant. Planting it in a container means you can enjoy its scent right on your patio or outside an open window.

chocolate flower
I love the chocolate flower buds; they’re delicate and different. Image courtesy of PlantSelect.

Rosemary (Rosmarinus officinalis). Rosemary is equally pleasant smelling and actually edible! I grow it every year in a container, and have several plants growing as ornamentals in our garden. It has evergreen foliage, so if you live in zones 6 to 8, you probably can keep it alive all year in the garden. In zone 6, it also might make it in a container, though I’ve had creeping rosemary burn from cold or snow even in zone 7. So either protect your container or bring it in, depending on the hardiness of the variety you choose. But back to enjoying rosemary! Plant it all alone near your kitchen for easy fresh cuttings, or in a group container. And if you decide not to take cuttings for cooking, your rosemary might eventually bloom lovely lavender colored blooms. At any rate, put it where you can frequently walk by and just rub your fingers over the leaves.

Rosemary_pot
My rosemary has survived sub-freezing temps so far up against the south side of the house. It still smells terrific, even after the wind blew leaves all over the container.
Creep_rosemary
Bees love this creeping rosemary, which requires little to no water in a container or landscape. This is all one plant; we had to cut some away in the middle after it burned. We should have knocked the snow off.

Ornamental grass (try blue fescue, silky threadgrass, or blue avena). Who says a plant has to flower to look great, especially in a container? I love adding a spike of height and texture with a grass, often in the center or back of a container full of colorful annuals. Most grasses need less water than flowering plants, and they look great blowing in the wind or adding height to a container, especially one placed up against the house. Many of them even flower. Just be sure to check the tag to see how high the grass normally grows before making your purchase.

And remember that plants always need a little more water when you first plant them, in extreme heat and when in containers than when in the ground. Containers usually dry out more quickly than ground soil – how much more depends on the container, soil you used to fill it and the location. And containers are microclimates, which means they might place your plant in colder, warmer or drier conditions than you realize.