2021 Elinor Teague past article | UC Agriculture and Natural Resources

Elinor Teague

December 2021 MG website column

December 2021 MG website column by Elinor Teague

Pruning scares lots of gardeners. One of the best things Master Gardeners can offer to home gardeners is to help them gain confidence in their gardening skills, especially pruning skills. I was lucky in my early days as a Master Gardener to have two great MG mentors, Bob Larson for fruit and nut tree pruning and Rodney Sakaguchi for Japanese maples. Both allowed me to follow them as they pruned and never snickered at beginner questions. A few years later, Michael Harman co-taught AEC rose pruning classes with me and cheerfully shared his expertise. Their generosity did indeed boost my confidence.

Here a few suggestion for ways we Master Gardeners can do the same for home gardeners and fellow Master Gardeners.

Encourage beginning pruners to learn from books that contain clear instructions and illustrations as well as UCCE MG pruning videos. Also encourage a review of YouTube pruning videos with the caution that they vary greatly in quality.Advise taking pruning guides into the garden and staring at each branch on the plants that need pruning until the written instructions make sense.

Orthos’ excellent guide “All About Pruning&rdquor; is available new and used online. It’s not expensive, the illustrations are some of the best, and it shouldn’t scare off a beginning pruner.

The American Horticultural Society’s “Pruning and Training&rdquor; is a fine next step up the pruning ladder of knowledge.

Suggest that beginners take a walk in Shin Zen gardens in Woodward Park or The Clovis Botanical gardens or a community rose garden, pruning book or video In hand, to see what good pruning looks like.

Suggest that beginners start small and keep in mind the motto “less is more&rdquor; when it comes to pruning. Pruning a small rosebush that is not an overgrown tangled mess of thorns and canesis a great first try. The existing structure of canes is easily visible so that decisions on what cane to cut are also easier. Mention that there is a beauty to a well-pruned plant. They’ll want to aim for a balanced, clean, symmetrical structure when finished.

Winter Orchard Care January 8, 2022 at Garden of the Sun. Click here to learn more.

Advise beginners to start the pruning with the most basic cuts. Always cut back to the junction (collar) between other branches or the trunk. Never leave stumps. Remove dead and diseased wood first, then cut out branches that cross through the interior of the plant. These first pruning cuts may be all that is needed to maintain the health and vigor of the tree or bush. More experienced gardeners will be able to recognize suckers, water sprouts and weak spindly growth that should be removed. Decisions on where and how to make heading cuts to control size and growth direction can be difficult even for experienced pruners. Patience and practice will guide beginners. Good pruning has a long learning curve.

Tool Maintenance Class December 11, 2021 at Garden of the Sun. Click here to learn more about this class.

Many gardeners are still using their Uncle Herbert’s garden tools most of which have heavy wooden handles and heavy thick metal blades. These tools may have lasted for years but newer lightweight composite tools with sharper, thinner blades make pruning easier on the body and make better cuts. Encourage beginner pruners to invest in better tools.

Elinor's 2021 past articles

Master Gardener’s website column November 2021

November 2021 MG website column

Climate changes have made it necessary for Master Gardeners to revamp the advice we give to home gardeners.Our Central Valley climate has always been very different from the rest of the country.Our climate is hotter and very arid, receiving less than 12 inches of rainfall annually.We have a long summer growing season that used to last from mid-April until late October and a winter that lasted only from Nov. 15th (first frost) until late January when the soil temperature rises to above 55 degrees, warm enough for seed germination.

Drought monitoring began in 2000.During these last 21 years average annual rainfall amounts have decreased and average monthly temperatures have increased. The longest recent continuous drought period lasted 376 weeks, from December 2011 until March 2019.

Continued drought is the greatest concern for gardeners in California but heat spikes are a secondary threat to plants. Heat spikes or waves are defined as lasting 5 or more days and nights.We have all noticed that nights do not cool off as in years past.In fact, according to a May 2018 OEHHA report nighttime heat waves have increased over the last 40 years.It’s these high nighttime temps during spikes that stress plants and trees the most.In our shortened winters we are now seeing a reduction in ‘chill hours’ necessary for fruit and nut production.During summer heat spikes we are seeing premature flower and fruit drop, even in plants that are well-irrigated.

Increased air pollution especially from wild fire smoke and increased CO2 levels are also threats to the health and vigor of plants and trees. Heavy smoke and pollution reduce the amount of sunlight reaching plants’ leaves, interfering with the process of photosynthesis and the exchange of atmospheric carbon for oxygen.

Here are just a few of the most common recommendations we need to revise for the hotter, drier years that are now expected to continue in the future.

“Full sun&rdquor; on plants’ labels indicates that the plant or tree requires at least 6 hours of sun daily.Previously Central Valley Master Gardeners cautioned home gardeners that almost all plants in Central Valley gardens need protection from the summer sun’s rays in late afternoon, the hottest part of the day.We now need to advise home gardeners that all plants receivingmore than 6 hours of full sun daily will require shade in the afternoon.And that during heat spikes many plants will require temporary full shade provided by umbrellas or shade cloth structures.We also need to revise our lists of heat, drought and pollution-tolerant plants to emphasize those plants most able to survive hotter, drier conditions.

Regular deep irrigation of mature shade-producing trees has had to be increased during these drought years.Additional deep irrigation for mature landscape trees and fruit and nut trees should now recommended whenever heat spikes are predicted.

Amending garden soil to improve water retention and drainage is critical.Recommended amounts of compost and humus amendments have been increased from turning in a two to three-inch layer of amendment before planting in spring and fall to turning in at least four inches of amendments into planting beds before each season.

Master Gardener’s website column October 2021

October 2021 MG website column

A thorough fall cleanup and as well as an evaluation of any pest insect, fungal or disease problems in the garden are among the most important yearly tasks for home gardeners.A fall cleanup should remove all the weeds and debris in the garden where pest insects hide and lay their eggs in late summer to over winter sheltered or hidden places.The evaluation should note what plants have had insect or fungal infestations, the insects and the diseases, and how serious the infestations were.

Here a few of the more common problems you’ll want to deal with this fall.

After feasting on cool-season cole and brassica crops in early fall, Bagrada bugs, a fairly recent stinkbug invader, congregate as adults to briefly overwinter hidden in woodpiles and even inside garden sheds.Use a dedicated hand vacuum to suck up the bugs.Bagrada bugs produce several generations each year.Getting rid of the fall/winter Bagarda bugs will really reduce next year’s attacks.

Weedy patches and undisturbed areas of topsoil can harbor the eggs and larvae of many pest insects.Grassshoppers lay their eggs in undisturbed top soil in summer to hatch next spring.Clear out weeds and use a wiggle hoe to cultivate the top inch or two of soil.You might also expose a few hidden cutworms when you do that.Spinosad or Bt, Bacillus thuringiensis will kill larger cutworms.

If you’ve had problems in spring with hoplia beetles chewing holes in your light-colored flowers, beneficial nematodes can help reduce the beetle populations.Hoplia beetles overwinter in lawns and undisturbed topsoil as grubs.Beneficial nematodes that kill the grubs can be purchased online or in garden centers. The nematodes can be sprayed in a solution onto lawns and soil in fall.

Fungal spores overwinter on fallen leaves and twigs or on bark surfaces.Anthracnose and camellia blight are examples of fungal diseases that are spread by splashing rains or sprinkler water in late winter and early spring.Rake up all fallen debris around trees that have had symptoms of anthracnose and dispose of the debris in the green waste bin.Sycamores, elms and oaks are the trees most commonly affected by anthracnose in the Central Valley.

The fungal spores that cause camellia blight overwinter in mulches or debris underneath the camellia bushes.In fall, replace the mulch under camellias that have shown signs of blight (brown blotches on petals, flowers that drop early) in early spring and dispose of the mulch in the green waste bin.

The fungal spores that cause peach leaf curl on peach and nectarine trees overwinter on twigs and bark.Clean up all peach and nectarine leaves and debris right after leaf fall in November and treat the tree with a copper solution.

The Central Valley’s rainless summers create a tremendous amount of dust.Heavy coatings of dust block plants’ breathing pores in their leaves and can weaken and even kill plants.Red spider mites thrive in dusty conditions.Wash dust (and pollutants and ash from fires) off plants this fall, trying your best to direct water back into planting beds.

Master Gardener’s website column September 2021

As the weather cools in mid to late September we can begin planting seeds and transplants of cool-season crops, flowering spring annuals and spring-blooming bulbs as well as transplanting trees and bushes. But choices of what to plant must be made in the expectation of another warm, dry winter followed by another summer with severe heat spikes that will entail continued water conservation.

All new perennial transplants including drought-tolerant plants require regular deep watering for two to three years after planting. Flowering annuals and vegetables require regular irrigation during their growing seasons. Fruit and nut trees need consistently moist soil at a depth of 8 to 12 inches in order to produce and hold crops.Existing shade trees need regular monthly deep irrigation during the hot months and into the fall months when their roots need to store water during dormancy.We are facing very difficult decisions on water usage.

Food vs. flowers.Many gardeners are switching to planting vegetables, herbs and leafy greens instead of annual flowering plants as a water saving measure and also as a form of mental and physical therapy during this pandemic. Nurseries and garden centers will begin to stock cool-season transplants in late September and early October, but stock sold out quickly last year.Starting vegetables, herbs and leafy winter greens from seed offers a greater selection. Unfortunately, seeds are also selling out quickly this year.As of mid-August a check of four well-known seed company websites showed that supplies of seeds and available selections for cool-season flowers and vegetables have only increased by about 20% since last year at the same time.

Many gardeners a discovering that seeds that have been saved for two to three years are no longer viable. It’s advised to store seeds in a cool, dry place.Cool places are becoming even harder to find as our climate gets hotter every year.Hot storage conditions cause the seed leaves that encase the seed itself to dry out and toughen, preventing germination or stunting leaf development. Those of us who have always stored our seeds in the garden shed have needed to move them inside.It will be a bit of a challenge to find places indoors to store dahlia tubers and fall-blooming bulbs over the winter.

Whether you’re planting from seed, planting your own homegrown transplants or nursery transplants, begin to amend the soil in planting beds this month with water conservation in mind.

Compost is the magic ingredient for increasing your soil’s ability to absorb and retain water.Kitchen-waste compost, worm compost and leaf compost are easily made in the garden itself and all are chock full of fresh micro-nutrients, micro-organisms and beneficial fungi.Many of the bagged composts and humus available at nurseries and garden centers have been stored outdoors in the heat and sun which kills the beneficial micro organisms.

Turn at least 4 inches of compost into planting bed soil to a depth of 8 to 10 inches and till that composted soil as little as possible until repeating the process during our next planting season in late January.

Master Gardener’s website column August 2021

Master Gardener’s website column August 2021

Research continues into the beneficial effects of adding compost to the soil either by turning it into the soil or by laying it on the soil surface. As UCCE Master Gardeners we have been made aware that turning compost into the soil significantly improves water retention, restructures soil texture, recycles organic waste and adds nutrients and beneficial microbes and fungi, reducing the need for chemical fertilizers and other types of soil amendments. Exciting new research is showing that compost sequesters carbon in the soil and thereby removes carbon from the atmosphere. Plants absorb atmospheric carbon during photosynthesis; their roots release that carbon into the soil and then release oxygen into the atmosphere.

The SF Chronicle published an article (July 1, 2021, “Regenerative farms fight climate change&rdquor;) on experimental work on regenerative farming also called carbon farming in which a thin layer of compost is being applied to grazing lands in Marin County. The improvement in productivity of feed crops is impressive as is the potential for reducing carbon in the atmosphere.

What can we Master Gardeners take away from the newest research? There are three carbon-sequestering regenerative farming practices that can be applied to small-scale home gardening; planting perennial plants rather than annuals, planting cover crops such as clover and reducing or even eliminating soil tilling.

During their longer lives, perennial plants develop more extensive root systems than short-lived annuals. Bigger root systems can absorb more carbon. Adding more perennial plants to well-composted soil in urban gardens could help reduce carbon, perhaps not in great numbers, but every small step to moderate climate change is worth the effort.

Cover crops are used in farming to outcompete weed growth and to fix nitrogen into the soil between crop plantings. Few cover crops (vetch, ryes, mustards) will be suitable for growing in an urban landscape, but some including white and strawberry clovers can make a beautiful lawn. Clovers’ deep roots make it more drought and heat-tolerant than lawn grasses and clover also fixes nitrogen into the soil. The flowers on clover attract bees and other pollinators as well.

Tilling releases carbon held in the soil back into the atmosphere. It also breaks up the sometimes yards-long threads or hyphae produced by mycorrhizal soil fungi. Those microscopic threads perform many important functions in the soil. Hyphae break up and remix soil particles increasing aeration and water retention. Every time we till we break up those hyphae and temporarily disrupt their functions, affecting plants’ vigor and health. Tilling as few times a year as possible and reducing the area to be tilled can actually improve the soil and its ability to sequester carbon.

There’s still time these next summer/fall months to start a kitchen waste, fallen leaves or all-inclusive compost pile to create homemade fresh compost that can be used as a nutrient-rich and micro-organism-rich soil amendment when planting and transplanting this fall or as a soil topping. Check the UCANR website for up-to-date information on composting as well as worm composting.

July 2021 Master Gardener website column

Master Gardener’s website column July 2021

Not all pruning of deciduous trees and bushes is done in winter.Winter pruning encourages rapid new growth in spring: summer pruning which suppresses growth when done properly can control size on overly-vigorous trees and bushes.Summer is also the best time to prune out shoots and suckers when they are smaller than six inches and before their growth reduces the tree’s or shrub’s vigor or deforms the shape.

Several species are pruned during the dry summer season to prevent disease pathogens from being carried into fresh cuts by winter rains. Diseased branches on these same species are also pruned out in summer.

Eutypa dieback on apricot trees is caused by the eutypa fungus which enters pruning wounds in winter and causes sudden limb death in summer as well as large, oozing cankers.Check apricot trees branches for signs of cankers in summer and prune out diseased branches before the cankers spread to the trunk.

Olive knot and oleander knot are bacterial infections caused by related pathogens.In summer check olives and oleanders for knots or galls which are round, hard brown easily visible unnatural growths on stems or branches.Remove galls in summer and sterilize tools after making cuts to prevent the spread of the bacteria.

Wisteria and bougainvillea are two examples of vining plants that grow rapidly in summer.Prune wisteria shoots and tendrils in summer to maintain the shape and size of the vine.Deadhead and cut back bougainvillea in summer to keep them in flower.Trumpet vines, jasmines, and honeysuckle vines are so vigorous (as are most vining plants here in the Central Valley) that they can tear apart fences, raise roofing shingles, and climb through the garage walls if not cut back hard after bloom in late summer. Climbing rose vines will send out long, light green flexible canes in summer.Cut these canes back to the base or twine them into the support, trying to arrange them to grow horizontally.Most climbing roses set flowers on horizontal canes.

Where and how to prune any bush or tree is an art as well as a science.It takes practice and many ‘Oops!’ moments to gain confidence in your pruning skills.Here are a two suggestions for pruning guide books both of which provide a very comprehensive list of trees and shrubs common to our gardens as well as very detailed instructions and illustrations.

The American Horticultural Society’s “Pruning and Training, A fully Illustrated Plant-by Plant Manual&rdquor;.(ISBN -56458-331-7) is available from its publisher at www.dk.com. It comes in both hardback and paperback. The information in this guide is taken from the Royal Horticultural Society’s original publication (same author, Christopher Brickell) and is incredibly detailed with precise instructions on pruning, training, renovating, etc for each plant type. For example, the section on deadheading bougainvillea in summer describes “cutting entire flower clusters back to a young, non-flowering sideshoot&rdquor;. So helpful.

The list of trees and shrubs and the proper pruning techniques for each is less comprehensive in Ortho’s “All About Pruning&rdquor; than in the AHS guides, but does cover the most common plants in U.S. gardens.Its illustrations are very good.This guide is not always in print, but is available new and used online.

June 2021 MG website column

June 2021 MG website column

Container plants Hybridizers and growers have been busy developing small plants for small spaces. There’s an ever-increasing selection of dwarf or container size plants but demand has outpaced availability. Plants and seeds are still in short supply. We can start seeds for fall transplants of cool-season crops and flowers here in the Central Valley in late July or early August. I’d suggest beginning to monitor seed catalog websites now and place your orders for seeds as soon as possible. Fortunately seed catalogs have many choices and many offer the opportunity to pre-order their seeds now.

Any plant can be grown in a container. Root size at maturity usually determines the size of the container. However, Japanese maples and bonsai (juniper, maple, camellias) are able to live for years in small pots with regular root, branch and tip pruning. In this case, root restriction also inhibits root growth. Citrus, sweet bay trees, avocados , evergreens and many other tree types can be successfully grown in pots. Size on many tree varieties is controlled by branch pruning, often into formal topiary shapes .Don’t be hesitant to try growing your favorite bush or tree in a pot, just study up on growth habits and pruning techniques.

For long-lived plants choose really sturdy containers such as heavier terra cotta and glazed pots. Resin pots tend to crack easily. Resin and plastic pots are lighter and therefore easier to move around, but they don’t breath and can also crack. Place wheeled or castered saucers under bigger pots to make repositioning easier. To encourage well-rounded growth, turn pots one quarter around as you notice uneven growth.

Use fiberglass screen material (the best) to cover drain holes on pots that will have permanent plantings. Coffee filters work well for a year or so, then decompose.

Newer formulations of potting soil mixes are often enriched with humus and organic ingredients such as earthworm castings, fish emulsion, oyster shells, kelp and low-nitrogen manures. Potting soils like these should contain large numbers of beneficial micro-organisms and fungi. However, our high summer temperatures can kill beneficial micro-organisms and fungi, especially in bagged soils. Plan on adding your own fresh homemade compost and earthworm castings regularly to boost the beneficials’ populations. Because nutrients leach out with every watering, potted plants need fertilization more often than those planted into the garden soil. The type of fertilizer used and frequency of fertilization depends on the plant species. Vegetables and flowers might need feeding twice a month when setting buds; trees can be fed two or three times during their growing season.

Use fiberglass screen material (the best) to cover drain holes on pots that will have permanent plantings. Coffee filters work well for a year or so, then decompose. Some gardening experts still recommend using pot shards or rocks to cover drain holes. Large pieces can shift and block holes.

Liners for hanging pots have improved. Coir, jute and burlap are not long-lasting and as the material disintegrates, it looks tatty. Some new fabric pot liners are brightly colored: some are now made of breathable plastic interlaced or moss/plastic mixes. Handmade moss liners look good for years and are easy to construct.

May 2021 MG website column

May 2021 MG website column

It looks as though we’re in the middle of another drought year.So far this year Central Valley rainfall amounts are approximately 60 per cent of normal with no significant rainfall expected until late fall. This drought year is a continuation of the drought in California which has lasted from 2006 until now with one wet winter break in 2016/2017.

Gardeners are usually excellent observers of weather patterns. Many gardeners will have noticed that during these last drought years the summer heat in the Central Valley has arrived earlier than in previous years and that intense heat has endured longer, well into late fall.Heat spikes have also occurred during which temperatures have risen above 110 degrees for longer periods of time than normal.Gardeners’ anecdotal information is confirmed in a NASA research article published Sept. 6, 2020, “California Heat Wave Fits a Trend&rdquor;, ( ww.earthobservatory.nasa.gov).

California Master Gardeners can be leaders in efforts to educate home gardeners in the more stringent water conservation practices that are so critical in a continuing drought.

Drought conditions stress plants causing poor flower set, premature flower drop and small crops of smaller fruits, nuts and flowers. Heat spikes cause severe stress to plants and can kill them even though the soil is kept consistently moist. Dry conditions produce heavy coatings of dust which clogs plants’ breathing spores, weakening the plants and eventually killing them.Last year thick smoke from burning forests and grasslands created extremely poor air quality and obscured the light from the sun for weeks; leaves on plants and trees were coated with ash and soot.

Given the difficult growing conditions predicted for this summer, planting of seeds and transplants in May should not be recommended.Seedlings and transplants will be stunted by the first hot spells and become more susceptible to pest insect attacks.Gardeners should be prepared to regularly monitor and treat for increased populations of common pest insects like whiteflies, aphids and red spider mites.

In addition to a regular watering schedule which should be adjusted weekly or even daily according to the weather, well-established landscape plants and trees and fruit and nut trees should be deep irrigated now and at least monthly during the summer.This deep irrigation is in addition to timed irrigation on the mandated county schedule. When heat spikes or heat waves are predicted, check soil moisture levels and deep irrigate when the soil is dry at a depth of 4 inches.Set up soaker hoses and bubblers now and increase the number of drip emitters if necessary to fully irrigate root zones. Wash dust off plants often and try to direct the water into planting beds.

The hardest part of gardening during severe heat and drought is making the decision on which plants will receive the majority of the water.Large shade trees should be at the top of the list, followed by food plants. Annual ornamentals will be last on that list.Survey your own garden and create an irrigation priority list which takes into consideration the amount of water each individual plant usually needs to stay vigorous in summer as well as the age of the plants and the extent of the root system.A one-year old drought-tolerant sage plant will require more water than your twenty-year old well-established rose bush.

April 2021 MG website column

April 2021 MG website column

Springtime in the Central Valley is usually warm with few spring showers and no heavy rain storms that keep humidity levels high.Our short spring is followed by long hot, dry summers.The summer heat and lack of rain do not allow for the proliferation of most fungal problems.

The most common fungal disease problems that bring gardener’s questions to Fresno County Master Gardeners in spring are anthracnose on sycamore, oaks, ashes and elms and powdery mildew on roses as well as on the tender new leaves of summer vegetables.Treatment for both types of fungus are not easy and not very effective.The severity of symptoms will depend on the weather.The warmer and wetter the spring season, the worse the symptoms and effects of anthracnose; a mild, drier spring will contribute to powdery mildew problems.

Anthracnose disease causes the first leaves in spring to develop brown patches. On sycamores and oak trees the patches or lesions appear between leaf veins.On ash trees the patches are irregular.Infected leaves fall off, defoliating trees from the bottom up, leaving some green leaves on top of the tree.A second crop of leaves will sprout after the first have dropped and infected trees usually recover well.However, there may also be some twig and branch dieback on severely infected trees.

Chemical fungicides are preventative when sprayed on healthy tissue, but do not control or eliminate the fungus on infected trees.Some tree companies recommend root injection of fungicides but this practice is not recommended by UCCE.Spraying is not always completely effective, timing is difficult and it’s expensive.The best recommendation for control of anthracnose is regular cleanup of all fallen debris during the growing season and in winter to reduce the numbers of fungal spores that can be spread by rain or splashing water. Winterpruning directed to ensure good air circulation will also help reduce anthracnose severity.

Powdery mildew is not caused by high humidity levels in spring.It develops in mild temperatures (60 to 80 degrees) and on plants in shaded areas or in areas in the garden with poor air circulation.We see only a brief period of such moderate temperatures in spring so that the signs of powdery mildew infections are often missed until a little later in the growing season.

The first signs of powdery mildew are white spots on both upper and lower leaf surfaces.Powdery mildew spores can be washed off leaf surfaces during this first stage.As the fungus spreads, leaves turn brown and fall off and buds and new green growth become distorted.I’ve also noticed that after temperatures have risen enough to kill the powdery mildew spores, leaves on previously infected plants will show holes or areas of thin brown leaf tissue.Many gardeners will mistake these holes or brown patches for some type of insect damage.

Treat for the first signs of powdery mildew by washing off leaf surfaces and by applying horticultural oils or neem or jojoba oil.Applications of sulfur products will prevent powdery mildew problems but only if applied before the first signs of infection. Plant resistant varieties in sunnier spots with good air circulation.Sometimes the only solution for treating plants like roses which suffer severe powdery mildew infections every year is to remove the plant.

March 2021 MG website column

March 2021 MG website column

What makes a plant invasive?According to the national invasive species information website, www. invasivespeciesinfo.gov, “an invasive plant is 1) non-native and 2) it causes or is likely to cause economic or environmental harm&mldr;&rdquor;. The California Invasive Plant Council’s website, www.cal-ipa.org, Plants A to Z, identifies invasive plants as those that spread widely and easily and that out-compete native species.

In researching invasive plants used in landscapes for this column, I was surprised at how many of those listed were common in Central Valley gardens.Bamboo (running) has been know as an invasive plant for decades, but the list of the “16 most invasive species you’ll find at a nursery&rdquor;, given at www.epicgardening.com, also includes landscapers’ favorites such as Japanese barberry, Chinese privet (Ligustrum sinesi), Japanese spirea and nandina.

A quick look around your garden might just turn up several common but invasive species. And, following the descriptions of invasive plants given above, you might be able to add a few invaders you’ve identified to the lists.

In my garden, former owners (meaning, I didn’t do it) planted Japanese spirea, nandina, and Chinese privet as well as Mexican feather grass (Stipa tenuissima) and Euphorbia characias. The last two plants were in a separate drought-tolerant landscape zone.Mexican feather grass has been identified as an invasive plants, but Euphorbia characias has not yet been added to the lists and is still available in nurseries and garden centers.Although the feather grass and the characias were pulled out four years ago, seeds of both still sprout every spring.The characias is particularly invasive; hundreds of tiny seedling reappear every year, the wiry stems are tough to cut with a wiggle hoe and the roots easily penetrate through the mulch into the soil making them hard to pull out if more than two or three inches tall.

I’d add California bay trees (Umbellularia california) to the invasive species list as well.There are six large mature California bay trees that surround my backyard. They produce enormous numbers of bay berries that root easily on the soil or mulch surface and, if not pulled out when very small, will quickly establish long tap roots.The berries are big enough to be slippery.The trees also produce numerous suckers on their roots which are tough to cut and which must be cut off precisely at the base in order to prevent regrowth.Lots of extra work keeping the bay trees at bay.

Xylosma was planted for many years as a hedge or filler plant.Xylosma is also a very invasive plant; the seeds remain viable in the soil for many years and unless the roots are completely removed they will continue to produce wiry, tough new branches.Many of the gardens in my older, established neighborhood have branches of long-removed xylosma shooting up through more recent plantings.

As the list of species and cultivars of species of invasive plants grows, it’s important to keep up with the most current research in order to prevent inadvertently adding invasive species to our gardens.

February 2021 MG website column

February 2021 MG website column

Even though an atmospheric river brought significant rainfall amounts to the Fresno/Clovis area at the end of January, rainfall totals are only about 1/3 of the average annual of 11.5 inches.This might well be another drought year for Central Valley gardeners.

Our winter ends and our spring usually begins in late January or very early February when soil temperatures warm to 55 degrees or above.You’ll know when winter has ended when you see the first springtime weeds sprouting in your garden.

Here in the Central Valley, we normally resume fertilization in early or mid February.Fertilizer application rates should be adjusted when water is limited.

Application rates for all flowering landscape plants and spring and summer vegetables should be reduced in the spring and summer growing seasons this year in order to prevent flushes of new growth that can be damaged by heat and drought stress.It’s normal for flower buds to fail to develop and for the flowers on drought-stressed plants to fall prematurely.Applying more fertilizer won’t help. We can expect to see stunted growth on some plants, especially new transplants.Fruits and vegetables will be smaller this year with less juice. If this is a drought year, try fertilizing your plants and trees with half of the recommended amount or half the amount you’ve previously applied.

Choose fertilizers with 5% or less nitrogen to prevent rapid growth of tender new green growth. Granular formulations take longer to dissolve so that the nutrients remain available to plants’ roots over a longer time than liquid formulations. Granular formulations can be applied monthly; liquid formulations are often applied bi-weekly.

Amend the soil in planting beds now, before setting out transplants or sowing from seed. Adding large quantities of compost will improve drainage as well as water retention.It used to be recommended to lay down and turn in a two to three-inch layer of compost or humus.Recent research has shown that ‘more is better’ and ‘fresher is better’ with compost.Turning in a four-inch layer of compost is now considered the minimal amount.

Fresh compost contains significantly more live beneficial micro organisms and beneficial fungi than compost that has been stored in hot conditions (like our summers).Beneficial micro organisms and beneficial fungi attach to plants’ roots, increasing the roots’ surface area and the ability to draw up water and nutrients from the soil.

Day and nighttime temperatures were above average this winter with fewer chill hours or hours below 45 degrees. Timing for the fertilization of fruit and nut trees changes when dormancy is prolonged by a lack of sufficient chill hours. When chill hours are insufficient (chill hour requirements depend on species and cultivars) fruit and nut trees break out of dormancy later than normal.Leaves are late in appearing (delayed foliation); the blossoming period is longer and blossoms drop prematurely and their quality is affected.Check soil moisture levels in the soil around fruit and nut trees in February and deep irrigate fruit and nut trees to keep the soil moist at 12 inches deep.Feed fruit and nut trees once this spring when you see the first signs of bud swell with a higher-nitrogen fertilizer such as ammonium sulfate but at half the recommended rate.

January 2021 MG website column

The official annual Audubon Christmas Bird Count ( www.audubon.org) is just finishing up.This year the count has lasted from December 14th to January 5th.Participants in this bird tally sign up ahead of time to work with “circle leaders&rdquor; to establish a record, as comprehensive as possible, of all birds observed within proscribed circles. A second annual bird count, the annual Back Yard Bird Count ( www.birdcount.org), is also sponsored by the Audubon Society, but is much more informal and a great way to study the birds in your own neighborhood.This year the back yard bird count will be from February 12th until February 15th.

Guidelines for finding, identifying and listing as many birds as possible can be found on both websites.You can also enter your results on ebird.org, another bird counting site.The website, www.thespruce.com has good photos and of course the Audubon field guides and pocket guides to birds are very helpful.

December 2020 MG website column

December 2020 MG website column

In December and January most gardeners are occupied with pruning deciduous trees and bushes, but there are two important garden chores that are often overlooked during the busy holiday season.In the winter months, gardeners need to constantly monitor soil moisture levels in different spots their gardens and to be prepared to protect vulnerable frost-tender plants from freeze damage.

Check soil moisture levels in your garden before and after rainstorms. You might be surprised to find that the soil in some areas, like those under evergreen tree canopies, in container plants or next to fences or structures, remains bone dry while the soil other more open areas is damp near the surface.Evergreen tree and bush canopies can prevent rainfall from soaking the roots under the canopies and the foliage on container plants can also block rain.Our rainstorms usually blow in from the northwest or western direction; fences and buildings can block much of the rain from reaching the soil near the eastern or southern sides of structures.

Map out the rainfall patterns in your garden and arrange for supplemental irrigation in consistently dry areas.Use a trowel to dig three or four inches into the soil in planting beds and near trees.When the top three to four inches is dry, it’s time to deep irrigate.If your automatic sprinkler or drip emitter system is designed to irrigate by zones, set timers to water drier areas for longer periods of time.Or set up soaker hoses or small oscillating sprinklers to slowly soak the dry areas to a depth of 12 inches which is where most plants’ and trees’ roots lie.

Lawns are usually planted in open areas that receive more rainfall.Cool-season grasses including fescues and perennial rye and warm-season grasses like bermuda grass are both dormant in winter.They may not need any supplemental irrigation during December and January if rainfall amounts are sufficient.If rainfall is light, adjust automatic timers keeping in mid that warm season grasses generally require 6 to 9 minutes of irrigation (by rainfall or sprinklers) in winter.Cool season grasses need just 8 minutes of irrigation a week in December and 15 minutes weekly in late January when they begin to exit dormancy.

Here in the Central Valley we can see frost on the roofs starting in mid-November until mid-February.Our coldest temperatures of the year often occur in late December when it’s common to experience several nights of hard freezes when temperatures fall below 28 degrees.

Save a few of your old towels and small blankets to use as freeze-protection coverings for semi-tropical and tropical plants including bougainvillea, canna, citrus and some fern varieties.When temperatures are predicted to fall below freezing or when you can see the stars on a cold winter night, cover your plants and deep irrigate the soil around them; irrigate again after the freeze has passed.Wet soil stays warmer than the frosty air.You can also use burlap, canvas tarps, straw, cardboard and wood and canvas frames including market umbrellas that can be placed over small citrus trees in containers.

Non-breathing plastic can transmit the cold to plant tissues.Remove any coverings during the day to allow light, air and sun to warm and dry the plants