What's Hot Archive 2019

2019 · 2018 · 2017 · 2016

burnt trees

January 2019, by Barbara Hill

I’ve been hearing that soil can change during a wildfire, and actually repel water. Is this true? How does it happen?

It is true that with intense heating, soil can become water-repellant, or hydrophobic. In a hot wildfire, a waxy substance is created when plant material is burned. This substance penetrates the soil as a gas and solidifies as it cools, covering the particles with a waxy coating. This creates a layer that is generally up to one inch thick, but can be thicker. Plant roots and soil microorganisms help break down these hydrophobic strata, although thicker layers may persist for a year or more.

When the amount of water infiltrating the soil is reduced, it can lead to increased runoff, erosion, flooding, and lower water quality, as well as negatively impact plant growth. Find out ways to identify and treat hydrophobic soil

Forced blooms in a vase

February 2019, by Barbara Hill

What is force flowering, and how do I do it?

Force flowering the branches of deciduous, blooming trees and shrubs is an easy way to bring the color and fragrance of springtime into one’s home. By bringing cut stems into the warmth and light, you’re tricking them into thinking it’s spring. You can force-bloom quince, spirea, forsythia, redbud, pussy willow, dogwood, spicebush, and serviceberry. Cuttings from fruit and nut trees, such as apples, peaches, cherries, plums, and almonds, can be successfully forced as well. Select branches with a large number of buds, being careful to remove only those that preserve the plant’s shape and structure. Cut at an angle, and immediately place in water. Place indoors in bright but indirect light, and change the water every three to four days. A show of blooms should appear in two to four weeks.

peach blossom

March 2019, by Barbara Hill

I keep seeing “chill hours” listed on fruit and nut tree tags. What are they, and why are they important?

Like Goldilocks and her porridge, trees don’t want the weather to be too cold when, after a long winter’s nap, they produce new, tender buds – but they don’t want to wait until it’s too hot, either, because they’ll miss out on a full season of growth and fruiting. How does a tree know when it’s “just right” to resume growth?

Trees produce hormones in the fall which stop growth processes and initiate a state of rest. Even though dormant trees appear to be asleep, fruiting trees and shrubs are still paying attention, and keeping track of the temperature – specifically, chilling (roughly, temperatures between 32F and 45F degrees, also known as winter chill or vernalization). Growth inhibiting hormones will keep the trees safely in dormancy until a certain amount of winter chill has been accrued. This prevents them from being fooled into growth during spring-like midwinter warm spells and, when the right number of chill hours has been reached, signals that it’s the optimal time to break winter dormancy.

Chill requirements can vary widely, depending upon the tree type and variety. In general, a tree’s chilling requirement should come close to the amount of winter chill normally received in the area where it’s planted. If varieties with higher requirements are grown in milder climates, too little chilling will mean that blooming and leaf regrowth may be delayed, and fruit set will be poor. Conversely, if a tree with a low chill requirement is grown in colder climes, it will break dormancy too soon and suffer late-winter freeze damage.

Fortunately for Butte County gardeners, most of Northern California receives between 800 and 1500 hours of chilling each winter. This means that most commercially available fruit and nut trees will find our climate “just right.”

For more information:
The California Backyard Orchard: Tree Selection

fruit tree thinning

April 2019, by Barbara Hill

Fruit thinning seems wasteful to me – I want more fruit, not less! Do I
really need to do it?

Although it may seem counterintuitive, you and your fruit trees will both benefit by early spring thinning. Removing those tiny apples and plums now will result in a big payoff at harvest time, since fruit provided with plenty of elbow room will be larger and more flavorful, and less vulnerable to disease. Unburdening those limbs is an investment in future harvests, too, as trees overtaxed by an excess of fruit may be more prone to sun damage and disease, and overladen branches are susceptible to breakage. Plus, by consistently leaving too much fruit on the tree, we run the risk of eventually enduring years with next to no harvest at all: unthinned trees may become alternate bearing, a "feast or famine"-type cycle in which a tree produces excessively one year, and little the next.

Learn more about fruit thinning.

fruit tree thinning

May 2019, by Barbara Hill

Recent articles about Lyme disease have me concerned, but since I’m not a hiker, I don’t have to worry, right?

The good news is, tick-borne diseases are rare, and following a few simple, preventative measures will greatly reduce your chance of exposure. These little pests can be found in lots of places, however, so gardeners, picnickers, and even those with indoor/outdoor animal companions should join their wilderness-loving neighbors in tick awareness.

Once hatched, ticks have three life cycles, all of them parasitic. Mature ticks climb grasses or shrubs to seek hosts, while immature larvae and nymphs—essentially, tiny versions of the adults—hang out in leaf litter and on branches, logs, and tree trunks. But don’t fret—you can relax and enjoy your al fresco exploits by:

  • Regularly inspecting clothing or exposed skin, and doing a full body check at the end of the day.
  • Wearing long-sleeved tops tucked into full-length pants, which are in turn tucked into socks.
  • Applying repellents or acaricides (a pesticide that kills mites and ticks) to skin or clothing.
  • Using veterinarian-recommended collars and/or topical or oral products that kill and repel ticks on dogs and cats.

Learn more about this topic at Lyme Disease in California and Prevent Lyme Disease.

field of buckwheat

June 2019, by Barbara Hill

What can I do this summer to improve the soil and keep weeds out of my unplanted vegetable garden beds?

An excellent way to suppress weeds and enrich soil is to grow a summer cover crop. Buckwheat is a popular choice, as it grows in a wide variety of soils, germinates quickly, and creates a dense, weed-squelching canopy in just a few weeks. The fine roots improve tillage, and its profusion of white flowers will attract pollinators, parasitoids, and other beneficial insects to your garden. Cut, mow, and till back into the soil before seeds set. Buckwheat’s tender stalks and roots decompose quickly; in two to three weeks, your bed will be ready for another crop. In our climate, several plantings can be grown in a single summer. Photo by Alex Stone.

For more information, see:
Buckwheat as a cover crop
Overview of cover crops


July 2019, by Barbara Hill

My coast redwoods have always looked sickly, so I’m having them taken out. Can you suggest a replacement that would do well in Butte County?

As you’ve discovered, even though coast redwoods can sometimes be found in Central Valley stores, they only thrive in the moist, humid climate of the Northern California coast. Fortunately, there are plenty of tough, drought-tolerant conifers that are well-suited for our hot, dry summers. An excellent alternative would be a deodar cedar (Cedrus deodara), a majestic conifer that resembles the coast redwood, but requires much less water. Photo by Lazaregagnidze.

For more information: 
Cedrus deodara
Drought Tolerant Conifers