What can I plant under oak trees?
The key to planting under oaks without killing them is to use species that have the same water requirements, i.e., little to no summer irrigation. This means grass is OUT! The best ground cover with the canopy of the oaks is mulch, the fallen leaves and twigs from the tree. These decompose and release nutrients back into the soil, moderate the soil temperature, reduce storm water runoff and support a complex soil foodweb that is beneficial to the tree. Competing plants with different irrigation needs destroys this system, and root pathogens infect the tree. A good strategy for obtaining seasonal color under the trees is to use pots that are watered either by drip or by hand. These pots can hold all the thirsty colorful plants like azaleas, begonias, impatiens, camellias, etc. that are a problem for the tree when planted directly in the soil.
How can I make my landscape more fire safe?
The best strategy is to first think about how to make your house as fire safe as possible, reducing the possibility of ignition during a wildfire. Class A roofing and fireproof siding, with enclosed soffats and decks is a great place to start. From there, start at the edge of the structure and work your way outwards. Are flammable pines and eucalyptus trees immediately next to the house? Is there an irrigated zone around the perimeter of the house? Many of the older homes in the Santa Monica Mountains are well integrated into their surrounding landscapes, most of which is chaparral and very flammable. A combined effort to protect the structure and then reduce adjacent flammable vegetation is the best plan. Think long term, and plan the changes over time. The LA County Fire Department has numerous resources on how to plan zones around your home. A list of plant species that reduce fire danger is a good place to start. Remember that the vegetation surrounding your home is part of why you want to live in the mountains. An integrated, sustainable vegetation management plan that respects the local ecosystem and works with it should be the goal.
Is there a better way to do brush clearance?
Each year thousands of acres of vegetation are cleared to the ground around the homes in the wildland interface zone of the Santa Monica Mountains. When mature chaparral is removed, it is frequently replaced with exotic annual grasses like mustard and bromes, all of which are extremely flashy flammable species! They grow quickly in the spring and then die off, leaving acres to be mowed, often several times. A more cost effective strategy is to replace these flashy exotics with perennial natives that are less flammable, need less clearance and additionally provide deep roots to hold slopes as well as wonderful wildlife habitat. For those with larger areas to clear, a long term planting plan is needed. Because the invasive annuals leave behind huge seed banks, it makes sense to solarize the soil to kill these seeds before planting natives, but if natives are planted in the fall after the first rains, they will eventually take over.
What are invasive plants?
Invasive plants are those species that take over the landscape, out competing all the other species present and dramatically altering the soil conditions to favor the reproduction of their seeds. In the Santa Monica Mountains, annual mustard and many annual grass species have become so well established that many people don't realize that they are recent immigrants from all over the world. Many ornamental plants have been imported into the Los Angeles region, but only a few become aggressive and overtake the landscape. If you live in the wildlands of the Santa Monica Mountains, it is important to plant responsibly and avoid using known invasive exotic species.
Common invasive species that are a problem in the Santa Monica Mountains include:
Yellow star thistles
Ailanthus (Tree of Heaven)
For more information on invasive exotic plants, check these links:
Wildland Invasive Species http://tncweeds.ucdavis.edu/
This is a great website to learn about plants that you should seriously consider removing from your property.
To look up a specific plant go to: http://tncweeds.ucdavis.edu/esadocs.html
How can I get rid of invasive plants in my yard?
Many people use herbicides to kill invasive exotic plants, but these may have unintended consequences. A variety of mechanical means may be more suitable, including repeated cutting, digging up the plants (be careful on slopes!), covering with black tarps, pouring boiling water on the plants, and prescribed burning (done only by appropriate agencies). Whatever method you use, remember that repeated effort over many years may be needed to finally eradicate the unwanted plants. Persistence pays off and replanting with natives can help speed up the process!
How can I protect birds while trimming trees on my property?