Welcome! Journey with us through future posts, and discover ways to use water responsibly and make every drop in the landscape count utilizing better landscape practices (BLP's).
Here in Orange County, mother nature just can't make up her mind. Is it spring? Summer? Winter? Temperatures varying 20 to 30 degrees from day to day due to unusually hot temperature spikes, or unseasonably cool days, have confused the plants in our landscapes throwing flower and growth patterns completely out of whack. For many plants in the landscapes, now would be a good time to start removing spent blooms, or "dead-heading", to encourage additional blossoms and get those back on track.
Generally, it is best to perform heavier pruning on landscape plants while they are dormant in the winter. This avoids shocking the plant. But if a plant just needs a quick clean-up to maintain a pleasing shape or to promote flowering, the rules change.
Below you will find some helpful tips on when to prune common landscape trees and shrubs.
Avoid heavy pruning in the spring. If a little light pruning is necessary for shaping at this time, go ahead and prune, but this isn’t the time for drastic pruning.
Dead or unproductive limbs and branches may be pruned off at any time. If you’re unsure whether or not a branch is truly dead, scratch the bark with a fingernail. A living branch will appear green beneath the bark.
If a plant flowers in the spring, it can be pruned immediately after it has finished blooming for the season. Plants that bloom in the early spring set their flower buds in the fall, winter or early spring pruning of these plants would reduce the amount of spring blooms for them.
Shrubs that bloom on new growth in the summer or fall should be pruned in the winter. This will encourage the plant to put out new growth the following spring, and more new growth means more flowers to enjoy.
To avoid spreading any disease amongst plants, always disinfect your pruning shears before moving from one plant to another. A quick dip in denatured alcohol or a 10:1 chlorine bleach solution, work well as a disinfectants.
The following is a list showing some common landscape plants that may be pruned this time of year.
Flowering Almond - Prune in summer, after blooming.
Azalea - Clip off spent flower clusters and prune immediately after blooming.
Barberry - Prune after flowering.
Boxwood - Prune late fall through early summer.
Butterfly Bush - Remove spent flower spikes to encourage more blooms. Prune in late winter through early spring while dormant.
Camellia - Prune after flowering, and in early summer to encourage branching. Pruning too late in the summer and fall will remove next year’s flower buds.
Ceanothus - Prune in late spring to early summer, after blooming.
Clematis - Timing depends on variety. Spring-bloomers are pruned in late spring, after blooming. Summer and fall bloomers need little pruning, but can be pruned to shape while dormant in winter.
Cleveland Sage - Remove spent flower spikes to encourage re-bloom, and prune to shape after the final bloom.
Diosma - Shear lightly all over after bloom to keep the plant compact. Don’t cut back hard.
Euonymus - Prune evergreen varieties late fall through early summer.
Hydrangea - Prune spring-blooming varieties after blooms fade, summer-blooming varieties late fall through winter while dormant.
Magnolia - Prune in late spring to early summer, after blooming.
Mock orange - Prune in midsummer, after blooming.
Ornamental Flowering Plum - Prune dead or unproductive branches in early to late spring after blooming.
Pussywillow - Prune mid spring to early summer, after blooming.
Pyracantha - Blooms on old wood, prune in early summer.
Roses - Timing varies by variety. Roses that bloom on last year’s canes are pruned after flowering. Roses that bloom on new growth are pruned in spring when leaf buds begin to swell.
Salvia ‘Indigo Spires” - Pinch back to keep compact otherwise it will get "leggy".
Spirea - Prune spring-blooming varieties (Bridal Wreath) in early summer, after blooming. Prune summer-blooming varieties in midwinter, while dormant.
Statice (Sea lavender, Linaria perezii) - Cut off dead blooms when they become unsightly.
Westringia rosmarinifolia - Prune in late spring or early summer (like now) by shearing all over once a year after bloom. (Blooms are insignificant.) If growing too large, shear more frequently to keep it compact.
Wisteria - Remove spent flowers after blooming. Prune new growth in late summer to shape plant./span>
Be sure to catch Irvine Scene’s “Spring Gardening” episode airing on ICTV channel 30 in Irvine. It is also available on their website at this direct link: http://www.cityofirvine.org/cityhall/citymanager/pio/ictv/irvine_scene.asp
The video buffering on the website is a little bumpy but the sound should come through okay.
This episode features UCCE Master Gardener volunteers demonstrating container planting, touring the Great Park Food & Farm Lab, giving landscape design tips; along with Darren Haver, UCCE Water Water Quality & Resources Advisor/South Coast REC Director, who discusses a few landscape features homeowners may install to reduce water use and irrigation runoff such as warm season turf, low water use plant selection and hydrozones, various irrigation retrofits, pervious surfaces, and driveway slot drains.
One of the main backdrops of the episode are the demonstration landscapes located at the South Coast Research and Extension Center in Irvine. Tours of the landscapes are available by appointment only. Interested parties wishing to request a tour to view the various management practices which have been installed to reduce water use and minimize landscape water runoff may call (714)733-3970
This article from the Sacramento Bee sums up the UC Davis Arboretum All Stars program nicely. Read on about the criteria that is used in selecting the top 100 plants for California landscapes which use less water and require less maintenance.
The inserted photos are just a few of the species being evaluated by UCCE Master Gardeners here in Orange County at the South Coast Research and Extension Center.
UCD Arboretum All Stars
By April Vail Fri, May 06, 2011 Sacramento Bee
One of the toughest hurdles in planting a garden is selecting just what to plant. Finding plants that will look good AND thrive in your garden can sometimes be tricky as environmental factors such as sun exposure, rainfall, soil type, and seasonal freezes have a profound effect on how plants will perform in your garden.
Fortunately the UC Davis Arboretum, in partnership with the California Center for Urban Horticulture (CCUH), aims to simplify the selection process with their Arboretum All-Stars list. Drawing from the Arboretum’s vast pool of plants collected over the last 75 years and the experiences of horticultural staff, the All-Stars list identifies the top 100 performers for California gardens. These plants have been selected for their beauty and ability to prosper in California’s Mediterranean climate (characterized by hot, dry summers and winter rainy seasons).
The Arboretum All-Star Program started in 2004 when Ellen Zagory, Director of Horticulture at the Arboretum, and a colleague, Diane Cary, came up with the idea as a way to promote plants that are attractive, drought tolerant, require little maintenance, and will grow easily in our climate.
Those All-Star characteristics help the gardener save time by requiring less maintenance and save money by requiring fewer inputs of water, pesticides, and fertilizers. Those same characteristics also help the environment by reducing pollution, conserving water, and attracting beneficial wildlife. Through grants, a partnership with the CCUH, and the aid of volunteers, the Arboretum All-Stars Project gained footing.
“The All-Stars were selected by five horticulturalists from the UC Davis Arboretum.” Ellen explained. Each plant had to meet specific criteria. 1) They had to look attractive through most of the year. 2) They had to grow well in our Mediterranean climate. 3) They also had to be test in the Arboretum. Based on their experiences each horticulturalist listed their top plants and rated them in categories such as “low maintenance”, “drought tolerant”, and “attracts beneficial wildlife. The top 100 ranked plants became the Arboretum All-Stars.
Several Arboretum All-Stars plants have undergone extensive field testing to determine how they would perform under four different levels of irrigation. These tests helped determine what watering regiments the plants responded to best. To test the All-Star plants under a variety of California climates, 14 Master Gardeners from various regions of the state have volunteered to grow and document the growth of these plants in their demonstration gardens. These tests are ongoing.
The Arboretum All-Star plants are available for viewing in several gardens throughout the 100 acre UC Davis Arboretum and also in All-Stars demonstration beds at their Teaching Garden site. A searchable listing of the Arboretum All-Stars is available on the UC Davis Arboretum All-Stars website .
For more information visit:
UC Davis Arboretum All-Stars website
or, California Center for Urban Horticulture
Have you ever taken a walk through your garden and all of the sudden just been taken aback by the unexpected beauty of a certain plant, or collection of plants? Recently I had that very experience.
Working in the landscape on a continual basis you have a tendency to be a little more critical of a plant's vigor and it's beauty. Growing in one our demonstration landscapes here at the South Coast REC are a couple of Ceanothus x pallidus 'Marie Simon', a hybrid of early 19th century French origin related to some of our California Native Lilacs such as Ceanothus 'Concha'.
Planted as part of a research project two years ago, the scrawny 1-gallon plants would not have been my first choice. During the first year they were nibbled on by rabbits, infested by aphids, the foliage seemed to continually wilt and appear somewhat anemic, and lest we not forget the few very unassuming, washed-out pink blooms. Yet somehow these dainty plants continued to bounce back ever so slightly. The one thing that was growing on me was the color of the bark - a nice reddish-burgundy color that blended well with the medium green foliage.
After reading that this species responds well to being cut back after it flowers, in the early fall we did just that removing approximately 1/3 of the growth.
During the second year, we noticed fewer aphids and less yellowing and tip-burn on the foliage. Still, the blooms were just not that impressive. I could not wait until the end of the evaluation period to perform a little shovel pruning. As done the previous year, we pruned in the fall, however just enough to clean up the shape and any dead branches.
This last March was the end of the evaluation period for this plant. Every time I walked out to the landscapes, I would look at these plants thinking "your days are numbered, I just need to find something to replace you with". Now it could have been my idol threats being sent telepathically, the above average rainfall this last season, or the more realistic explanation that these three plants have matured and are now established after two years, but returning today from the three-day weekend, I was pleasantly greeted by the beautiful plumes of pink flowers balanced on their burgundy perches engulfing these delicate plants as you can see by the picture below.
Needless to say, these landscape beauties have earned a reprieve from the henchmen. This is definitely a plant to be grown in the Irvine area, you just need a little bit of patience.