Category Archives: plant maintenance

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.

burned_heuchera_leaves
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.

yellow_lemon_leaves
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.

What to Do in the Garden in Wintry Weather

toyon-berriesTwas the weekend after Thanksgiving and all through the house, not a creature was stirring not even a gardener. I should probably do something productive, but what? Should I be good and do a little light weeding? Maybe I can muster up the energy to plant a few more bulbs. Come spring I’ll be happy I did. Then again I could make notes of my gardening successes and not so great horticultural decisions. “I know”, I say to myself, “this weekend I’ll revel in what I don’t have to do in the garden”.

I don’t need to prune trees and shrubs at this time of year. Other than clipping a few OLYMPUS DIGITAL CAMERAwell placed branches to use in a holiday wreath, I’m off the hook for this task right now. Deciduous trees are still in the process of losing their leaves and are not fully dormant. Evergreens shrubs and conifers can be trimmed lightly but most shaping is done when they start growing in late winter or very early spring.

The season is pretty much over for me except to enjoy what’s left of fall color and the ornamental grasses waving their seed heads in the wind. A lot of perennials are dying back but I’m not in a hurry to neaten things up. The seed heads left in the garden supply food for birds and other creatures while the foliage provides shelter for the plant in the cold and frost. Remove anything that has turned slimy or just plain unattractive but leave berries and seed heads for food and winter interest.

hakonechloa_winter2At this time of year my garden is visited mostly by chickadees, nuthatches and goldfinches. They will spend the winter here and I’m doing them a big favor by not cutting back brown foliage containing nutrient-rich seed heads. Some of the reliable seed producers that I won’t have to clean up this weekend include artemisia, aster, coreopsis, penstemon, sedum, lupine, salvia, black-eye Susan, coneflower, phlomis, monarda, agapanthus and grasses.

Chickadees gather hundreds of seeds in fall and early winter and store them in hiding places to ensure themselves a food supply later in the season. They are a remarkable bird that we take for granted being so common. I read in Audubon magazine a couple years ago that a chickadee weighs about as much as a dozen paperclips but their body is large for their weight. This means they have to ramp up the number of hours they devote to feeding. At night chickadees cram themselves into tiny cavities and shiver, burning the day’s fuel to keep from freezing.

Hummingbirds still need a nectar source at this time of year. Anna’s hummingbirds live in this area all year long. So In addition to the plants in my garden that supply nectar I keep my feeders up year-round and keep them clean.
They need your nectar even more in the winter when very little is in bloom. In addition to nectar rich natives like mahonia, my abutilons are a winter favorite for them.

Other tasks I can put off at least for this weekend include planting wildflower seeds. I see California poppies coming up all over the place. Nature knows when the time is right. Well, maybe I’ll broadcast a few working them into the soil very lightly. I need to hoe off some early weeds that would compete with them. How many calories aren’t burned in light gardening? I might just reconsider not being a total couch potato this weekend.

Firescaping-Part I

shaded_fuel_brake_sign.2048I drove through the Groveland area near Yosemite a couple of days before the Rim Fire started on August 17th. The local talk over Tioga Pass was then about the recent Aspen fire in the Sierra National Forest. The Rim fire has now burned 400 square miles of forest and cost $122 million to fight to date. What started as a 40 acre fire when discovered exploded to over 100,000 acres within 2 days. It is now the 3rd largest in California history.

Remote sensing satellite images indicate that virtually all the vegetation is dead on nearly 40% of the burned area. Chaparral and oaks will resprout but ecologist say it could take 30 to 50 years for the forest to reestablish itself. It scorched some of the last remaining old growth in the Stanislaus National Forest. Two years of drought and constant slow warming across the Sierra Nevada  worked to turn the Rim Fire into an inferno. For years forest ecologists shaded_fuel_brake_example.2048have warned that Western wildfires will only get worse. The fuels get drier and drier.

shaded_fuel_brake_example.2048There have been two wildfires close to where I live in Felton, one of which was only 5 miles away on Martin Grade in Bonny Doon several years ago. How can I protect my home? Is there a landscape that is safer in a wildfire than another? Which plants burn more readily?

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.

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.

Next week I will discuss plant spacing arrangement and maintenance to help you prepare a fire-safe landscape around your home.