Fire safe landscaping

There have been two fires close to where I live in Felton, one of which was only 5 miles or so away on Martin Grade in Bonny Doon.  This started me thinking: what is a landscape that is safer in a wildfire than another?  Here is what I found out.

Many people think they have to clear everything within 30 feet of their house to truly have a defensible space.  This is unnecessary and actually unacceptable because it leads to soil erosion and the destruction of animal habitats.  What we should want to do is retain the character of this beautiful area we live in, provide the food and shelter that our native wildlife are accustomed to AND reduce fire risk. 

For example, grasslands mowed to leave 4-6" of height allow insects, reptiles, amphibians, and small mammals shelter, food and a place to reproduce. Leaving 4-6" standing also provides some erosion protection and shades out some of the weeds that follow disturbance.

Fire safe landscaping is a term used to describe defensible space.  It can look like a traditional landscape.  The idea is to surround the home with things less likely to burn and place them to provide separation between canopies and avoid creating fire ladders. Many homes may not have 30 ft. between their house and the property line but following these guidelines will help.  Plants in this area need to be the slowest to ignite and should produce the least amount of heat if they do burn.  There are plants with some fire resistance which include drought tolerant Mediterranean climate selections as well as natives. 

The key to fire resistance, though,is maintenance and keeping the moisture in the foliage high.  This may mean deep infrequent watering every month or two during the summer months.  For example,  Baccharis pilularis or dwarf coyote brush is generally considered highly flammable if its lush green top growth covers a hazardous tangle of dry branches and leaves several feet high.  Trim this plant down low in early spring, remove the dry undergrowth, follow with a light feeding and watering and the new top growth is now resistant to fire.

Drought tolerant plants with some fire resistance if properly maintained include trees like strawberry tree and western redbud.  Shrubs include escallonia, pittosporum, dwarf pomegranate and coffeeberry.   Groundcovers for areas closest to your house include ornamental strawberry, red fescue, and sedum.  Perennials to try:  yarrow, bush morning glory, coreopsis, fortnight lily, hens and chicks, daylily, lavender, penstemon, santolina,sticky monkey flower and society garlic.  Vines that resist fire when maintained and watered occasionally include pink jasmine, white potato vine, cape honeysuckle and star jasmine.     

In areas 30-70 ft. away from your house plant should be trimmed and thinned to create well-spaced groups and help prevent a fire in the wildland from spreading to your home.  Be cautious with slopes.  If you have a large lot, the fringe area should be inspected and maintained regularly to eliminate any build up of dry brush and litter.  This reduces the chance of surface as well as crown fires.  Extremely flammable plants have a high content of oil or resin and should be separated from each other, removed of dead branches and lower limbs, and kept free of dry debris anywhere around your property.  Extremely flammable pyrophytes like hollywood juniper, pines, fountain grass, japanese honeysuckle will need a higher level of maintenance. 

Other common plants that are highly flammable are manzanita, california sagebrush, california buckwheat, toyon, rosemary, deer grass and purple hopseed.  If you have these plants on your property yearly pruning and maintenance is important. All vegetation, including native plants and ornamentals in a residential landscape, is potential wildfire fuel.  Vegetation that is properly pruned and maintained, however, can slow a wildfire and reduce the amount of heat around your home.  Irrigation is vital in a fire safe landscape to maintain plant moisture especially in the 30 ft around your home.  Mulching around your plants will preserve this precious commodity in these times of drought.  Plantings beyond 30 ft. should be irrigated occasionally but to a lesser extent.  As you get 70-100 ft from the home, native plantings that require little or no irrigation should be used.

These are just come of the many tips for fire safe landscaping.  Find out more from the California Department of Forestry .

Sudden Oak Death Syndrome ( SOD )

InDay Lilypreparing for a consultation for another site under native oak trees at risk for SOD I found the latest host list published by the Sudden Oak DeathTask Force . The new list updated March 2008 also lists plants naturally infected and lots of information re. spreading the fungus as well as tips on sanitation. The latest information on prevention and keeping the immune system of your trees up if also available. I did find that a few of the plants that I was going to recommend for homeowners with oaks on their property have now been listed as vectors. They are coffeeberry, toyon, berberis aquifolium, manzanita and some varieties of ceanothus. This is important information for all of us to know.

Big Basin State park

Spent the afternoon hiking in Big Basin State Park in search of blooming Western azaleas. There are several large specimens right at park headquarters Western Azalea but I wanted to find some out in the forest. Our hike took us up into the shaded understory of old growth redwoods and douglas firs and the largest huckleberries I’ve ever seen. The weather was perfect. Earlier in the week temps hit mid 90’s but today was barely 80 degrees and very pleasant. It really wasn’t until we hit the lower part of Dool trail that we found the elusive Western azalea growing in the sun along the stream. The scent of this plant fills the air. Wonderful. Seems this plant will get quite large and grow happily in the shade but it just won’t bloom unless it’s in the sun. I plan to search more trails in the park for this very fragrant flowering shrub.

Designing under native oaks

We are all interested in unthirsty plants these days. When I design gardens under our native oaks there are several principles that I follow that I want to share with you. Drought tolerant plants are a must in this situation. Evergreen oaks even have special needs requiring a different plant palette than deciduous oaks like blue and valley oaks.Bush anemone

Most oak roots are in the upper 3 ft of the soil. The roots which take up water and nutrients are in the upper 12". The critical root disease zone for an oak is within 6-10 ft of the trunk. Do not irrigate plants or disturb the soil in this area. Outside this zone but within the drip line one deep watering per month is allowable for your plantings.
The leaf mulch that accumulates under a large coast live oak increases soil moisture and available nutrients, improves soil structure and moderates soil temperature. It’s a valuable resource that can be used in other parts of the garden. Never remove the entire insulating layer of leaves from under a trees canopy and don’t allow leaf mulch to cover the trunk.
One of the showiest California natives for planting under a coast live oak is carpenteria californica or Bush anemone. This evergreen shrub is resistant to oak root fungus and grows in sun or shade. Although this plant can get by with no summer water after becoming established, occasional summer water will help maintain a fresher look. The compact variety ‘Elizabeth’ produces a profuse display of white flowers with as many as 20 flowers per cluster. Cut back the top 1/3 to 1/2 of the stems after flowering to keep it compact.

Another deer resistant plant I like to use under oaks is Centennial ceanothus. This gopher resistant low spreading groundcover grows 12" high and 8 ft wide. Cobalt blue flower clusters cover the plant each spring. They also attract birds.
Western redbud can be grown as an accent shrub or small tree under coast live oaks. Large bluish grey rounded leaves have heart-shaped base making quite a show among smaller leafed plants. The magenta sweet-pea shaped flowers cover the branches in spring. Scattered flowers may also appear in late summer and fall. Flattened seedpods rustle in the wind in late summer and fall. And if that’s not enough to love about western redbuds they brighten the landscape with a fall color display of yellow or red leaves. Western redbuds respond well to pruning. Thin the oldest trunks each year to keep them growing vigorously. You can also cut the entire clump to the ground to rejuvenate it. This is truly a four season plant.

Combine any of these plants with coffeeberry, native irises, pink-flowering currant, toyon, berberis aquifolium, snowberry, hummingbird sage or yerba buena to complete your woodland garden and keep your oaks happy too.


What to plant under native oaks

Wester Sword FernVisited a site yesterday under dozens of huge native oaks. The clients wants to plant a little landscaping here and there to enhance her property but not endanger her oaks. Naturally both deer and gophers abound. The deer trail goes right below her deck. I was able to give her some information about planting near oaks and will develop a plan for her installer to follow. There are several plants like mahonia ( now berberis ) that would require little water after becoming established and also I am considering ceanothus ‘Centennial’ for an area below the flagstone landing. I’ll add more to this post as I develop the planting plan for this beautiful property. 


Hedges

bottlebrush

In writing one of my weekly columns for www.pressbanner.com/, I researched problems that occur with hedges and thought it would be interesting to share this info here:

To care for your hedge. Hedge plants should be pruned back by about a third when they are first set out. The second year, trim the hedge lightly to keep it dense as it grows. Don’t try to achieve the hedge height you want too quickly. Keep shearing lightly to keep the hedge thick without gaps as it grows to the desired height.

Once the hedge is as tall as you want it, your pruning technique should change.

Small leafed hedges should be sheared lightly whenever they look ragged. You can, if you want, simply allow the shrub to retain its natural shape. If you do shear, cut out farther than you cut last time to avoid bare spots and clusters of cut branches.

Large leafed hedges should be pruned one branch at a time with hand shears. Make your cuts inside the layer of foliage so that they will be hidden, leaving only fresh, uncut leaves on the surface. To avoid hedges with bare leafless bottoms shape your hedge so that the top is narrower than the bottom, letting light to the whole side. Leaves that do not get enough light will drop. Lack of water and nutrients can also cause this. This is especially important on the northern side or on any portion of the hedge that is in the shade of a tree. If your hedge has become bare at the bottom you can cut it back heavily in the spring to stimulate new growth at the bottom, then shape it properly as it regrows. Some shrubs,. however can be killed buy cutting them back too far. If you don’t know how a shrub will respond to a radical pruning, head one branch back to a leafless stub to see how it responds. If the stub sprouts new growth, the shrub can probably be safely cut back.

Hedges that have grown too tall and floppy have usually been allowed to grow too fast. Regular pruning encourages a sturdy structure and will strengthen a mass of wispy stems. Bare spots in a hedge are caused by old age and repeated shearing without allowing the hedge to grow. The problem can be alleviated by cutting away dead twigs, branch by branch and then shearing outside the last cut next time you prune.


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