We have discussed the why and the where of defensible space activities, but the what and the when and the how need greater exposition. The homeowner and family may do this work, or work can be contracted.
Defensible space work needs to be planned with recognition of the labor and dangers involved. While a first pass to pick up sticks and dead materials can be done by anyone, this initial step will undoubtedly need to be followed with tools and personnel.
Most people are not used to this type of activity, although it is often an extension of gardening activity, with many of the same tools.
It is best to plan the work in stages, with each step gaining more open conditions. One can mark the vegetation to be cut or to be left, either in the mind or physically with some flagging. Often this stage allows one to step back to see the next steps more clearly before you commit to action.
After assessing the needs and difficulties, starting with a lopping tool allows one to get rid of the small stems that inhibit movement through the wildland. Cutting at the base (but out of the dirt) will allow for the entire plant to be removed at once, and allow for easy future management of the stump, if needed. Of course, a worker should be able to recognize poison oak as well as the pyrophytes you want to remove.
Once the undergrowth is either removed or trimmed to remove all dead branches, the trees can become the focus. Trees to be retained may need pruning with a handsaw. Other trees may need to be cut using a chainsaw.
Preparing for chipping means getting the material to a location next to access and “indexing” the ends. This means stacking the brush to be chipped in a parallel manner, with large end toward the access road, and relatively flush for easy grabbing.
Every pruning cut on live wood is a wound. A branch needs to be cut so to not damage the tree and also to leave no stub. This does not mean making a cut flush with the bark, but instead cutting just outside the branch collar. Cutting in this way minimizes the impact, since branches compartmentalize decay and keep rot away from the main stem.
Many large trees can be disfigured or killed by improper pruning, so be sure of yourself or call a certified arborist before work begins.
The branches to remove are those which are either dead or which have parts which reach below eight feet (or so) from the ground surface. Steeper slopes often need higher pruning. For tree health, never prune more than ½ the height of the tree.
Branches which provide a screen or which are particularly useful or attractive may be left, if the area of the lower tree crown is open and has no flammable vegetation for 10 feet around the area.
Overhead pruning work can be and dangerous. Head and arm protection are essential, while face and neck covering will make falling sawdust a great deal easier to endure.
Pruning done in the spring and summer can attract bark beetles to conifers, while pruning oaks in areas of sudden oak death should be done during the dry months. Constraints and hard dirty work make it easy to ignore the need for pruning, but remember that fuel ladders promote crown fires - the worst of wildfires. The good news is that once done, pruning needs only occasional attention, since the removed fuel will not return. back to top ...
While managing vegetation to make your situation more fire safe, you are also altering the habitat for what lives there.
Many times, removing debris piles also reduces the rat population. You also may uncover snakes, squirrels, birds of all types, and certainly arthropods and other small life forms. For the most part, whatever is disturbed will quickly find a new home further away from your areas of highest value.
Remember that removing dead vegetation more than 1/2 inch in diameter is a key to preventing the passage of a hot wildfire.
The forest floor has a life of its own, and generally should be left undisturbed. The duff and litter will turn into mulch with vital nutrients to nourish the forest over time. When chipping, casting the chips on the surface to a depth of 4 inches is a good way to retain soil moisture while also inhibiting weed growth. Deeper piles may build heat as vegetation decomposes and should be spread out to avoid potential ignition.
Workers removing trees and shrubs should be alert to what is living there. If active nests are encountered in trees planned for removal, it is best to cut from August to March to avoid impact to young birds.
Another consideration regarding when to cut may be the activity of insects and diseases. With the threat of bark beetles, the disease Sudden Oak Death (SOD), and many other pests, it may be difficult to find the right time to best fulfill your plan by doing the actual cutting and pruning. All host material for SOD is best left on site where it is.
This is not a time to delay! If concerned, call the Master Gardeners and they can usually answer your specific questions over the phone. They are available MWF 9-12 at 707-253-4221 or toll free at 1-877-279-3065.
If working in a drainage where water sometimes flows, it is best to tread lightly and remove only pyrophytes and small dead materials, leaving in place any big wood (more than 12 inches in diameter or more than 4 feet long). The canopy should not be reduced in such places, which usually have higher humidity and lower tendency to burn.