All posts by Jan Nelson

I am a landscape designer and consultant in the Santa Cruz mountains in California. I write a weekly gardening column for the Press Banner newspaper. I am also a Calif. Advanced Certified Nursery Professional and managed The Plantworks Nursery in Ben Lomond, Ca. for 20 years.

Firesafe Landscaping – Part I

With the recent heat wave and the fires burning now in Southern California I?m reminded of our vulnerability to wildfires. The Martin Fire of 2008 and the Lockheed fire of 2009 together burned over 8,000 acres. I often hike in Bonny Doon Ecological Reserve and live close-by where these fires occurred. There?s a large, burned manzanita along the trail that serves as a grim reminder of the devastation that wildfire left in it?s wake. The skeleton-like manzanita, ponderosa pine and many other plants are regrowing from seed left in the soil. The fire was so hot it killed even the plant crowns preventing many of them from re-sprouting. I?ve been monitoring the regrowth for years and it?s progressing nicely but you don?t want this to happen to your property. Is there a landscape that is safer in a wildfire than another? Which plants burn more readily?

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Manzanita burned in Martin Fire. Bonny Doon 2008 – photo taken in 2012 in Bonny Doon Ecological Reserve

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 due to soil erosion and habitat destruction reasons. We want to retain the character of this beautiful area we live in, provide the food and shelter that our native wildlife are accustomed to but also 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. Highly flammable plants should be placed, whenever possible, with low-growing and/or low fuel plants.

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 California natives and Mediterranean climate selections. The key to fire resistance, though, is maintenance and keeping the moisture in the foliage high.

burned tree 2015
Same manzanita showing surrounding regrowth in 2015

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.

Other considerations may be as important such as appearance, ability to hold the soil in place and wildlife habitat value. Some fire-resistant California friendly plants are western redbud, monkey flower, ceanothus, sage, yarrow, lavender, toyon, California fuchsia and wild strawberry. Also consider coffeeberry, flowering currant, bush anemone, snowberry, California wax myrtle and evergreen currant. Fire resistant plants from areas include rockrose, strawberry tree, Chinese pistache, barberry, escallonia, oleander, pittosporum, bush morning glory and wisteria to name just a few.

Keep your landscaping firesafe to protect your home.

What is a Sustainable Landscape?

I have a bat house on my property although the bats haven?t taken to it yet. I understand the importance of bats and bat conservation in the environment. I incorporate many California native plants in my own landscape and continue to add them to gardens I design. I encourage bees and other pollinators by creating a sustainable habitat for them in my garden. I use my water wisely conserving our finite water supply. I use organic pest control only if necessary to protect our watersheds from chemical contamination. I feel I am on the right track of sustainability and stewardship of the environment. But can I do more?

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Organic plant starts at Garden Faire

Last week I attended The Garden Faire held at Sky Park in Scotts Valley. As I walked around the exhibits and listened to interesting speakers all the while serenaded by world music I thought to myself how can one person put all this valuable information to use in their own lives and gardens? How can I live more in harmony with nature?

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Apple tree display at Garden Faire

How can I sequester more carbon by my plants to store in the soil? How can I protect the biodiversity already in place in my mixed redwood forest environment? Even though I don?t have the right conditions to grow my own organic food can I buy from growers who use ecological process on their farms? What native plants around my own house can I eat?

You hear the word sustainability used to describe everything from flooring to roofing to landscaping but what exactly is a sustainable landscape?

Sustainable landscapes are so well adapted to their environment that they require little in maintenance. Choosing plants adapted to your garden size, type of soil and climate keeps watering and fertilizing to a sensible level and reduces pruning as plants grow to the size needed and stay there.

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Urbanite retaining wall

Sustainable landscapes use recycled, salvaged, durable building materials whenever possible. They use mainly materials that are harvested locally and use imported stone as an accent. Sustainable landscapes try to reuse what you already have laying it out differently to look like a totally new landscape.

Sustainable landscapes clean the air and water. They increase on-site infiltration of rain water to reduce runoff and minimize the amount of contaminants washed into the watershed and the bay. By keeping water onsite it can move into the soil where organisms breakdown pollutants and naturally filter them out before the water reaches groundwater or our waterways.

Sustainable landscapes conserve water by installing and

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Swallowtail feeding on butterfly bush

maintaining high efficiency watering systems making every drop of irrigation water count. They create drought resistant soils by adding compost and mulch. They group plants by watering needs to irrigate them more efficiently.

Sustainable landscapes restore habitats by attracting native pollinators, beneficial insects and other organisms that reduce the need for pesticides. A sustainable landscape restores natural areas on the outskirts of your landscape to diversify your plant community.

Sustainable landscapes are responsive to the environment, re-generative, energy efficient and can actively contribute to the development of healthy communities.

Troubleshooting Plant Problems

Troubleshooting is a form of problem solving. And whether it?s a car problem, your smart phone, an irrigation system or yellowing leaves on a plant the goal is to solve it and make the product or process operational again. When you eliminate the potential causes of the problem hopefully the solution restores everything to its working order. Sounds like something Sherlock Holmes would say and it?s sometimes easier said than done as we all have experienced.

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sunburned heauchera leaves

A few weeks ago I received a text with pictures of some plants with brown spots and asked what I thought might be the problem with their plants. This was after the heat wave we experienced and after asking a few questions about irrigation, location and how long the plants had been in the ground, I determined that the plant leaves had been burned in a pattern consistent with the location of the beating sun. At this time of year plants are growing wildly and need a good soak moistening the entire root zone. The solution: Better to water deeply less often than lightly which might not reach all the roots.

The subject of how much fertilizer and what kind came up in another troubleshooting email thread between some fellow horticulturalists. The issue was whether to use another round of organic high phosphate fertilizer in order to encourage bud development on a notoriously short-season tree dahlia. After some lively discussion we decided that the early spring application of rock phosphate was sufficient. Sometimes adding too much phosphorus may actually hurt a plant by preventing the uptake of other nutrients which must also be available to the plant in order to prevent unexpected deficiencies to appear. A balanced fertilizer containing all three nutrients- nitrogen, phosphorus and potassium-was recommended for the remainder of the season.

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yellow leaves on lemon

Then there were some problems in my own garden. Well, it seems I am always trying to solve something with plants, pests or critters but this was with my lemon tree. At first I was perplexed when the older leaves of my lemon tree started turning yellow a couple months ago. The new growth looked fine so it wasn?t an iron deficiency where the young leaves display green veins along with the yellowish color.

It wasn?t a nitrogen deficiency either where the mature leaves slowly bleach to a mottled irregular green and yellow pattern, become entirely yellow and then are shed while the discoloration spreads to the younger leaves. I had fertilized in March with an all-purpose balanced fertilizer. Citrus are heavy feeders and require a steady source of nitrogen, the ideal citrus fertilizer having a ration of 3:1:1 (N:P:K)

After eliminating other mineral deficiencies or overwatering as the problem I decided that my lemon was simply dropping interior leaves which is normal after winter but I wanted to trouble shoot all potential causes to be sure citrus greening wasn?t the culprit. If it had been this deadly disease the leaves would have exhibited an asymmetrical pattern.

To quote Sherlock Holmes ?Once you eliminate the impossible, whatever remains, no matter how improbable, must be the truth.? I?ll try to remember that when I?m troubleshooting my next problem in the garden.