Cambrian: Opinion

Planting to replace dying Monterey pine trees in Cambria

We see the brown Monterey pine trees dead from old age, killed by drought, or made vulnerable by drought to fatal attacks by beetles, rust or pitch canker. We hear the whine of chainsaws and the roar of chippers as arborists try to remove the dead trees close to buildings, streets or power lines. We feel the heat and dryness and ask ourselves what will happen to the forest of Monterey pines.  

One answer might be that the forest will renew itself naturally. Seeds dropped over many years from mature trees will sprout when the right combination of moisture and sunlight streaming into the new openings in the forest occurs. Perhaps the drier, south-facing, already-sunny hillsides won’t be so lucky. 

What we can do

Is there anything we can do to help the forest regenerate? Can we plant trees during the drought, or do we need to wait for it to end? I believe we should plant some every year. Indeed, the current county tree removal permit process requires it.

Successive annual Thanksgiving plantings by volunteers on the Fiscalini Ranch Preserve, including during the first two years of the current drought, have helped to restore the pines to optimal habitat in the fog belt from which they had long been removed to open up pastures for cattle grazing. Those plantings, including during drought years, had high rates of survival for many reasons, including appropriate site selection, timing, strong healthy young seedlings, careful planting, initial watering in, mulching with pine chips, and the relatively minimal water needs of young trees with little green mass. 

Homeowner options

If you are a homeowner needing to replant because of trees removed from your property, you have two options: either replant on your own property four Monterey pines for every one removed or hire Greenspace to do it for you on your property or another site if you don’t have room for them on your property. Both options satisfy the county’s replanting requirement.

If you plant them yourself on your own property, you may purchase seedlings from Greenspace or from Growing Grounds in San Luis Obispo. Brad Seek has a method for getting mature cones to release their seeds, then growing them to a foot or so in height when they are ready for planting out. 

Imagine a 100-foot-tall tree growing there when you are choosing a planting site, avoiding power lines, proximity to buildings, etc. Where there is a stump of a Monterey pine is an excellent site. If it is on a hill, the uphill side of a stump will not only have years of accumulated duff to help mulch the seedling, but also, the roots of the previous tree will help trap and hold rainwater.

How to plant

The proper way to plant seedlings is deep, straight and tight

Plant the tree in soil at the same depth as grown in its container. Make the hole deep enough so the roots hang straight down. Step on loose soil around the tree (air pockets will dry out the roots). Water it with a quart or two, then mulch around it with wood chips to help retain moisture and minimize competition with grasses. 

Planting after the first rains have soaked the ground is best so that it will have the rest of the rainy season to establish itself. 

The first weeks and months after transplanting are when it might need an additional watering or two if it starts to wilt from insufficient rain.

Looking for cones

If you are not replanting for mitigation purposes, but perhaps to restore Monterey pines to appropriate sites where they had historically grown, a very simple method that can be employed any time of year is to gather cones and set them where you’d like trees to grow. 

Look under live, healthy trees. Look for big cones, not small ones. 

Choose cones that are light tan in color (not green or gray). The scales should be tightly closed, not open. If a squirrel has eaten only part of it, that’s OK. 

Because each seed in a cone was individually pollinated, there will be substantial genetic diversity from individual seeds from the same cone.