What's Hot Archive 2022
What's Hot in January
How can I provide habitat for ground nesting bees?
While we strongly recommend that you mulch your gardens—both ornamental and edible—for water conservation, soil health, and aesthetics, be sure to leave some areas of your yard free of mulch to provide nesting habitat for the non-social ground nesting pollinators, particularly native bees. Up to seventy percent of native bee species in the US make their nests in the ground. To attract and support ground nesting bees, choose a sunny, well-drained area of your yard and clear much of the vegetation (leave a clump or two of grass or another low-growing plant to prevent erosion). Don’t turn the soil in that area, as bees need stable soil to nest in (young bees spend up to eleven months of the year underground). Small holes in the bare ground will be evidence that these important insects have taken up residence in your yard. Congratulations!
Photo: Colletes sp Paludi by Syrio
What's Hot in February
What are chill hours and why are they important?
Most fruit and nut trees require a minimum number of chill hours during their dormancy to thrive and produce a decent crop. The traditional definition of a chill hour is any hour under 45 degrees F, usually referring to temperatures between 32 and 45 degrees F. Naturally, home orchardists have most success with varieties whose chilling requirements match up with the chill hours typically received in their area: choose “high chill” varieties (800–1,000 + hours) for cold winter climates, and “low chill” varieties (500 hours and less) for warm winter climates.
For instance, figs, olives, and quince have the lowest chill requirements, followed by persimmons, pomegranates, almonds, and chestnuts. Apples, apricots, cherries, peaches, and plums have higher chill hour requirements. In warmer winters, without a requisite number of chill hours for a given type of fruit, the tree might not bloom on time or at all, resulting in little or no fruit. Lack of adequate chill hours can cause a later and/or longer bloom time, leading to disease on the flowers, reduced fruit set, and poor fruit quality.
An excellent discussion of chill hours for trees that grow in temperate zones such as Butte County can be found in the article The Importance of Chill Hours for Fruit Trees.
Photo: Pluots at the Master Gardener Demonstration Garden. Photographer: Laura Kling
What's Hot in March
What do the 3 numbers on fertilizer bags mean?
We are glad you asked, because one of your garden tasks in March is to fertilize woody perennials. A very brief summary is included here; for more information, and clues for recognizing possible nutrient deficiencies, we encourage you to visit Understanding Fertilizers and Amendments.
All commercial fertilizers are labeled with three bold numbers. The first is the percentage of nitrogen (N), the second is the percentage of phosphorus (P) and the third indicates the percentage of potassium (K). (For instance, a bag of fertilizer labeled 15-10-6 contains 15% nitrogen, 10% phosphate and 6% potash.) Nitrogen, phosphorus and potassium (N-P-K) are the primary nutrient elements needed in the greatest amounts by plants. Of course, plants require more than just these three elements (there are at least 14 other essential elements necessary for plant growth). In general, we recommend fertilizing with lower numbers unless signs on your plants (such as yellowing leaves or chlorotic veins on leaves) are signaling a serious deficiency.
What's Hot in April
When is it safe to plant my summer vegetables out of doors?
The instructions on vegetable seed packets tell you to sow seeds out of doors approximately one to two weeks after your average last frost date (for green beans). For vegetables that you can start indoors, the directions (for tomatoes) are to start seeds indoors about six to eight weeks before the average last frost date. These estimates may vary depending on which vegetable you are planting.
In Butte County, this important date range depends on your location. For those gardening in Chico a handy chart of approximate frost dates compiled by UC ANR shows that in the spring the probability of frost ranges from 50% on or about March 21 to 10% on or about April 24. Unfortunately, Chico is the only Butte County city included on this chart’s list of 40 cities in California.
Another resource is PlantMaps, which displays average last frost dates for almost every community in California. According to this source, Chico, Concow, and Richvale all share an average last frost date between April 11 and April 20. For Paradise, it’s April 1 through 10, and for Oroville, it’s between March 1st and 10th (Oroville is earlier due to its foothill “banana belt” conditions).
In our rapidly warming climate, these dates are sure to shift around on the calendar. It might be fun and useful to keep your own records, noting when the last frost occurs in your neighborhood.
Photographer: Dawn Endico
What's Hot in May
What should I look for when shopping for plants?
CNPS offers two types of monthly classes to “get you growing with California native plants.” The “Native Gardening 101” series provides seasonal guidance and technical insights for native gardening while “Native Gardening Chats” features panel discussions which present diverse voices and topics in the world of native plant gardening.
Here at the eNews, we just finished watching “Nursery Shopping 101,” a step-by-step guide to choosing and planting native plants that will thrive in your specific garden conditions. Facilitated by CNPS’s Horticultural Program Manager and Horticultural Program Coordinator, and presented by a native plant nursery owner, the webinar featured useful and insightful tips on how to guide your own native plant selection by identifying your goals, such as:
- Creating a sense of place with a landscape that mirrors that of your natural surroundings
- Conserving water
- Growing fragrant and beautiful flora
- Nurturing edibles and medicinal plants
- Attracting wildlife
- Exploration, experimentation, and enjoyment
With a set of guiding principles, you can better select the plants for your space. The next task is to analyze your site conditions with these words of wisdom in the forefront: “Don’t fight your site!” Know your garden’s dimensions, its sun exposure throughout the year, and its soil type (more wise advice: “embrace your soil type” and match your plants to it). Keep your source of irrigation in mind—while many natives don’t want supplemental summer water, all newly planted species need some irrigation until they become established in your garden.
Selecting healthy plants means making sure the “root to shoot” ratio of pot depth to above ground growth is fairly even, the foliage is dense and healthy, and the plant has not become rootbound. Be sure to prep your site before planting, and for the best results, let the naturally existing plant communities in your region be your guide.
There were many more hot tips in this webinar, especially during the Q&A portion. We encourage you to tune in to the link above for this and other top notch webinars on Native Plants from CNPS.
What's Hot in June
by Laura Lukes
What native plants require very little or no summer water?
The best way to choose low water plants for your landscape is to see what is growing in the natural spaces in your area. Depending on your elevation, you might see sage, manzanita, deer grass, yerba santa, penstemon, valley oak, blue oak, buckwheat, buckbrush (and other types of ceanothus), mock orange (Philadelphus), redbud, ironwort, mallow, and flannel bush. Other low water plants which thrive in our Mediterranean climate include lavender, mahonia, cistus (rockrose), and most bulbs. While many regional nurseries carry natives to some degree, Floral Native Nursery (north of Chico at 14388 Meridian Rd) and Harvests & Habitats Nursery (behind 1078 Gallery at 1710 Park Ave., Chico), deal specifically with California natives.
In a “normal” water year, most plants that are native to northern California prefer little to no supplemental irrigation during our long, hot, dry summers (usually May through October). Average winter rainfall ranges between about 24 inches (for the valley) to 60 or so inches in the foothills. That said, very little has been normal or average around here for a few years. Our rainfall totals for several of our last winters were much lower than our historical average. This means that your drought tolerant natives may require more frequent supplemental water during the dry period (perhaps 1 to 2 times a month).
There are a few California natives which truly resent being watered in the summer, namely flannel bush, cistus, ceanothus, and mahonia.
Native plant gardens are at their best in the late spring and early summer; many natives take the summer off and can look a little ragged or spent. Remember that this is their way of dealing with the long dry summer and resist the urge to over-water them.
Photographer: John Rusk
What's Hot in July
My tomato plants are going nuts! Should I cut them back?
You must be growing indeterminate tomatoes, which are essentially vines that will grow and spread unless controlled by some means.
There are two types of tomatoes: determinate and indeterminate. The determinate tomatoes are well-behaved and grow into bushes which tend to produce fruit all at once. Indeterminate tomatoes, on the other hand, will continue to grow and fruit until weather conditions like lower temperatures, less sun, and (eventually) frosty mornings, stop them.
Determinate plants do not need pruning; you will reduce your yield if you prune. That said, if any branches of the plant are lying on the ground, feel free to tidy those up with a judicious cut close to the stalk.
But we do highly recommend pruning, pinching, and otherwise controlling your indeterminate tomato plants. A quick survey of resources on the internet reveals that there are many types of advice on tomato pruning, some of it conflicting. For more information watch this video produced by “Grow Organic” from Peaceful Valley Farm and Garden Supply in Grass Valley. It offers sound and easy to follow advice for tomato growers at any level of expertise. Pruning indeterminate tomatoes can result in healthier, larger produce. The video also provides some tips about how to avoid or address common tomato problems, such as blossom end rot and unsightly blotches on the fruit.
Nothing quite compares with a fresh tomato from the garden, so taking the time to care for your plants really pays off.
What's Hot in August
What can I do to help my plants through the hottest days of summer?
Both higher temperatures, and a higher number of days at those temperatures, can take the stuffing right out of our landscape plants, even those evolved in and adapted to hot and dry summers. Flowering species that were so luscious a month or two ago are looking sickly, and many of our favorite summer vegetables can suffer sun damage if exposed to too much heat and sun in the late afternoon.
Help is at hand! There is a large variety of shade cloths which you can use to protect plants that are exhibiting symptoms of sunburn, or that may just enjoy a break around 3 PM on. The cloth comes in different colors (primarily green, gray, and black) with a different percentage rating, from 30% to 80%. The percentage represents the amount of sun blocked by the cloth: for example, a 30% rating would allow 70% of the sun’s rays in.
For the best results, install the shade cloth on a simple frame along the sunniest side of your plant. Depending on the size of the plant you are protecting, you can drive t-stakes or plant stakes into the ground and clip the cloth to it; or you can bend flexible wire in a hoop shape over the plant and lay the cloth on it.
One of our informants says, “I use shade cloth routinely! Plants are much happier!”
Photographer: Jeanette Alosi
What's Hot in September
I want to plant a tree—what should I plant?
While visiting friends last week, enews was asked to recommend a tree for their front yard. SelecTree to the rescue! This handy online tree selection guide was developed by the Urban Forest Ecosystems Institute (UFEI) at Cal Poly.
You can customize your search for the perfect tree by a huge variety of parameters. How tall will your tree be once it’s fully grown? Do you want a California native? Do you prefer fall color? Will you be planting underneath power lines? What shape do you like? Would you like a flowering tree, or one that fruits, or both? How about leaf shape and color? What’s your USDA or Sunset hardiness zone? What kind of sun exposure will your tree receive? Do you need a tree that is deer resistant? Is your soil saline? How about water use?
With the click of your mouse and a few keystrokes, you can narrow down the choices to a tree that will suit your needs and thrive in its chosen location. To plant your tree, wait until the weather turns: the ideal time to plant is from late October into November, when we have mild weather and the possibility of rain. Cooler weather and higher humidity make it easier for plants to acclimate to their new surroundings, put down some decent roots, and generally enjoy life before the winter sets in.
Photographer: Laura Kling
What's Hot in October
I would like to support migrating Monarch butterflies. I know that they depend upon milkweed, but there seem to be many kinds of milkweed available in garden catalogs. Will any species of milkweed be helpful to Monarchs in our area?
The North American Monarch Butterfly (Danaus plexippus) stops in our area in the spring during its multi-generational, long-distance migration from the coastline of California and Mexico, where it spends winter, to locations as far afield as Arizona, Nevada, Idaho, Utah, Oregon, and Washington State. In order to help Monarchs traveling through our area, it is important to plant local species of milkweed (Asclepias).
The California native milkweed species that are most commonly available commercially and grow well in our area are narrow-leaf milkweed (A. fascicularis) and showy milkweed (A. speciosa). Other native milkweed species that are somewhat rarer include California milkweed (A. californica), heartleaf milkweed (A. cordifolia), wooly milkweed (A. vestita), and woolypod milkweed (A. eriocarpa). All of these species will grow in Butte County and are helpful to Monarch butterflies, whose caterpillars feed exclusively on milkweed plants.
Milkweed is also a great host plant for many other beneficial insects including bees, beetles, and lady beetles (ladybugs).
Use caution where you plant the seeds, as milkweed can be toxic to livestock.
Both heart-leaf milkweed and narrow leaf milkweed will be available at the Master Gardener Plant Sale on Saturday, October 1st at the Demonstration Garden at Patrick Ranch.
Photographer: Jeanette Alosi
What's Hot in November
I’ve removed my lawn that surrounded a tree. Now that I’m no longer watering the lawn, should I water the tree? How much water does it need?
During drought, many people commendably decide to remove their lawns and replace them with dry or low water landscaping. Removing thirsty lawns is a wise step toward conserving water and creating an interesting garden that provides habitat to pollinators, birds, and other important wildlife.
Traditionally, lawn landscapes have often included at least one shade tree, which will suffer from lack of water once the regular irrigation of the lawn is cut off, particularly during these dry winters. The value and importance of trees in the landscape cannot be overstated. Trees provide shade, helping the soil and plants beneath them to retain water during the heat of summer; and shade also lowers ambient temperatures within the shadow of the tree. So, how to water the tree once the lawn is gone?
The fix is quite simple. Get a 25 to 50-foot soaker hose (depending on the drip line of your tree) and arrange it in a circle around the trunk. Between once a month and once a week during our long hot dry months (usually April or May through October or November but sometimes longer), turn the hose on very low before you go to bed, and turn it off when you get up. (This uses much less water than you would think, and is very beneficial to the tree.)
How do you know how often you need to water? Keep an eye on the tree. How do the leaves, especially those at the very top of the tree look? If they are dry, burned, or falling off very early in the season, increase your watering schedule to once a week instead of once a month. You can stop watering altogether when the tree goes dormant. In the likely event of another dry winter, begin an irrigation schedule again in the spring when the tree begins to leaf out.
Photographer: Joby Elliott
What's Hot in December
I just planted paperwhites in water for indoor forcing. How long will it be before they start to bloom?
How nice that you’re kickstarting your spring indoors! Paperwhites are one of the most effortless bulbs to force. They’re also one of the quickest to come into bloom.
You can expect your first blossoms four to six weeks after you bring your bulbs into a bright, warm spot. If kept adequately watered and not too hot, you can expect blooms to last a week or more. Remember that the water should just barely touch the very bottoms of the bulbs. Once the roots are reaching into the water, keep the water level about a quarter of an inch below the bulbs. If the bulbs themselves sit in water they will rot. You can drop in a couple of chips of charcoal to help keep the water fresh.
Rotate the containers daily to establish robust and balanced growth. Planting up a new pot of paperwhites each week over 3 to 4 weeks ensures blooms from the holidays into the early spring.
Growing sweet-scented paperwhites indoors during the winter can add a special touch to your holiday décor, and a bowl or pot of paperwhites makes a fine gift. Enjoy!