Man’s Best Friend Detects Deadly Citrus Disease

The author and Sherman, a Welsh Springer Spaniel, at the Bonny Doon Ecological Reserve. Photo by Tom Trower
The author and Sherman, a Welsh Springer Spaniel, at the Bonny Doon Ecological Reserve. Photo by Tom Trower

If you have a pet dog it’s no secret that they are always happy to see you. Dogs provide us with companionship. They love us unconditionally and never seem to have a bad day. Their ability to read human gestures is remarkable. Even our closest relatives- chimpanzees and bonobos- can’t read our gestures as readily as dogs can. They pay attention to us as human infants do. This accounts for the extraordinary communication we have with our dogs. Some dogs are so attune to their owners that they can read a gesture as subtle as a change in eye direction.

Another picture of Sherman ‘cuz he’s just so cute. Dressed up for the Fourth of July.
Another picture of Sherman ‘cuz he’s just so cute. Dressed up for the Fourth of July.

 

Studies have shown that dogs were the first animal that humans started keeping as pets. No one can pinpoint the exact date, but estimates range from roughly 13,000 to 30,000 years ago. Archaeologists can tell domesticated canines apart from wolves through skeletal differences. The earliest dog bones, discovered in Belgium in 2008 are from 31,700 years ago. Ancient dog skeletons have also been unearthed near Ukraine and elsewhere across Europe, Asia and Australia, suggesting that canine domestication was a widespread phenomenon.

How did dogs become domesticated in the first place? The first ones were basically just tame wolves. Instead of the survival of the leanest and meanest wolf it came down to survival of the friendliest around the garbage pile at the edge of human settlements. Aggressive wolves would have been killed by the humans. Friendliness caused strange things to happen in the wolves. They started to look different. They no longer needed strong jaws and sharp teeth. Their noses got smaller, their ears floppy and they evolved the ability to read human gestures.

Fast forward to 2016 when the California Dept of Food and Agriculture reported in their ‘Food and Farming News’ that dogs are being enlisted to help protect citrus trees. Mary Palm, the USDA Animal and Plant Health Inspection Service (APHIS) national coordinator for the citrus pest program, said dogs have been successfully trained to detect canker disease and now Huanglongbing or greening disease in citrus.

Espalier lemon
Espalier lemon

Huanglongbing or greening disease (HLB) is a deadly bacterial disease that has decimated the citrus industry across the world. The USDA has already spent hundreds of millions of dollars looking for a cure. In California, nearly one-third of the state’s entire land mass or 21 counties are in quarantine for the bug- the Asian citrus psyllid- that can spread the disease HLB in citrus groves. The quarantine requires that fruit moved from those areas be free of leaves and stems and movement is restricted of any nursery stock that isn’t grown in a USDA-approved facility. In addition to many Southern and Central California counties, San Fransisco, Alameda, San Luis Obispo, San Mateo and Santa Clara counties are also under quarantine.

Dogs have long been known to be able to use their senses to detect things that humans require extensive technology to detect. “Over the past four to five years,” Palm said, “a researcher in Florida first determined dogs could actually detect citrus canker. They were very good at it.” Through research funded by USDA, there are now five dogs trained and tested daily to detect huanglongbing disease. Palm said in the next year or two certification criteria will be in place for other companies to train dogs and certify them as detectors. The dogs in this program have a 99 percent success rate at detecting HLB disease in blind studies.

So when you’re petting man’s best friend tonight appreciate all the great things he does for you and for our planet. What would the world be like without lemons and oranges?

Gardening Trends for 2016

Pieris japonica or Lily-of-the-Valley shrub
Pieris japonica or Lily-of-the-Valley shrub

As a landscape designer I try to stay abreast of the latest plant introductions and trends in garden design. Many of these new plants work well with our backdrop of mountains and naturalistic settings. Some new trends will appeal to those who grow edibles while some will appeal to the gardener who loves their garden but doesn’t have time to do a lot of maintenance. What’s new this year is a return to some old fashioned ideas.

Many of us are removing overgrown shrubs and replacing them with water smart, easy-to-care-for plants that will stay the right size in smaller spaces. There are new compact and dwarf versions of old plants that have been garden favorites for a very long time. The reason they have endured is because they are reliable. Good reason to look again at some old favorites.

Vignette composed of Summer Wine physocarpus, Phormium ‘Jester’, Elegia capensis, and Japanese Forest Grass
Vignette composed of Summer Wine physocarpus, Phormium ‘Jester’, Elegia capensis, and Japanese Forest Grass

I’ve wanted to grow a Ninebark in my own garden but this beautiful deciduous shrub normally gets too big for my space. Sure I could prune it regularly but I don’t want the ongoing maintenance to keep it the right size. Several new cultivars of physocarpus opulifolius are smaller while providing just as much drama. The varieties Petite Plum and Summer Wine both have that rich, dark purple foliage all season that blends so well with lime colored foliage or pink flowers. This mounding, fast growing, deciduous shrub is adaptable to difficult situations. It’s easy to grow and tolerates drought once established. I can even cut the showy, soft pink flowers to bring inside. The flowers are followed by attractive seed pods making this plant attractive all season long.

A new version of the drought tolerant Grecian laurel bay tree is available now that will only grow to 6-8 feet tall in10 years. Laurus nobilis is the one that adds the classic Mediterranean flavor to soups and sauces. Little Ragu is compact and handsome in it’s natural form or you can clip it into a formal hedge or topiary shape. When I moved to this area 30 years ago I made the mistake of using our native bay tree for a spaghetti sauce. Now I can grow the real deal and not ruin my sauce.

Other trending looks in the gardening world are to combine ornamental plants with edibles. Well, maybe this isn’t new to you but it’s a good reminder that your veggies don’t have to be in a special raised bed or plot but can by planted throughout the garden. Think tomatoes, pole beans and other vining veggies trained on an metal obelisk within a perennial bed. Or compact versions of beans, eggplant, chard, hot peppers, tomatoes or edible flowers like nasturtiums planted among your other plants or along path borders. These can be planted from seed where they are to grow making them super easy to enjoy later on.

Rhododendron ‘Pink Delight’
Rhododendron ‘Pink Delight’

Even if you’re not redoing your whole garden you can plant a small section or vignette using a more toned down palette. Whether it’s shades of pink or white or blue this look will give your garden a calm feeling. Add a place to sit and you’ll want to relax there with a book or beverage.

Everything old is new again from old fashioned flowers, bicolor blooms, solar lights for the garden, sharing extra produce with neighbors and super fragrant plants.

Looking at Grasses in a New Way

Calamagrostis Foliosa
Calamagrostis Foliosa

I regularly receive plant availabilities via email listing what’s looking good in that wholesale nursery for the week. Besides being a good reminder of plants that have fallen through the cracks in my memory many times I’m inspired to think of them in a new way. With spring around the corner – yes, hard to believe but true – this is the time to rethink your landscaping again. From saving water to saving time there are lots of ways to change what you have in your landscape to make it look more inviting and pleasing to the eye.

Tired of looking at all that moisture conserving but uninteresting mulch you spread last year? Whether you are replacing the lawn you allowed to go brown last summer or just want an expanse of water smart low grasses or grass-like plants for an area I’ve got some great suggestions for you.

 

carex meadow
carex meadow

If you want a lawn substitute that you can walk on but don’t need to use it as a play area there are California native and prairie meadow grasses that will be perfect for this kind of situation. They need little irrigation and even less mowing. Some can be planted from seed, others from plugs or sod. Good choices include Idaho fescue, Calif. and red fescue, carex pansa, Berkeley sedge, June grass and Hall’s bentgrass. Occasional shearing keeps them looking best but they may be left alone with no mowing at all. Weed control is important during establishment but a healthy stand may be sustained with virtually no weeding after that.

Other meadow grasses to walk on include buffalo grass and carex texensis. They stay short and can be either left alone or mowed every so often. Tough enough for soccer games yet soft enough for bare feet. Scotts Valley Water District has a good list on their website of lawn substitute grasses and other water conserving plants.

Other areas in your landscape might look great with an expanse of a grass or grass-like plant with a slightly taller profile. Here are some of my favorite ornamental plants that are water smart, have beautiful foliage and often showy flower heads to sway in the breeze and bring life to the garden.

Moor grass or more specifically Sesleria ‘Greenlee’ is a new-ish introduction. This evergreen, clumping blue-green grass grows to 1 foot tall and a little wider with rose-purple flowers in spring and summer. It tolerates a wide range of conditions from wet to dry, sun to shade and is hardy down to 0 degrees. Lovely planted in swaths to give your garden that restful feeling.

Libertia peregrinans
Libertia peregrinans

One of my very favorite small grass-like plants is Orange Libertia. Native to New Zealand this stunning plant is great back lit and planted in masses. Growing to just under 2 feet tall, the leaves are green in the center and bright orange along the margins. Lightly fragrant, pure white blooms appear in the spring. This beauty takes the sun or light shade and has moderate water needs. It’s hardy to about 15 degrees and forms colonies by rhizomes.

Blue oat grass is another small grass that add elegance to borders, containers and moonlit gardens. In late spring graceful stems bloom with delicate oat-like flowers that age to tawny brown by midsummer. Ruby grass, festuca ‘Siskiyou Blue’ and Chinese fountain grass are also small grasses that can be massed together for a stunning effect.

Plants with grass-like foliage like mondo grass, liriope, small phormiums and many of the dianella or flax lily are also water smart and can be used alone or in groups.

Time to start thinking of new ways to save water and time this growing season.

Do I Really Need to Dormant Spray and Prune my Fruit Trees?

Gummosis canker on dwarf nectarine- Photo courtesy of Sherry Austin
Gummosis canker on dwarf nectarine- Photo courtesy of Sherry Austin

A Facebook friend recently posted a picture of gummosis on her dwarf nectarine. While pruning her fruit trees she found the sticky stuff and shared her plight. While some folks post pictures of babies and political opinions on their Facebook page, my friends post pictures of plants and their fruit trees. Yes, if you haven’t already done so, this is the time to winter prune fruit trees and apply dormant spray to fend off diseases and insect pests. With rainfall expected throughout the spring this is not the year to omit this important task.

Why prune your fruit trees in winter? The reasons to prune fruit trees are to increase fruit production, develop strong 45-degree branch angles to support fruit load, remove limbs that grow down or straight up, maintain tree size and maintain fruit spurs. The dormant season is the best time to train a fruit tree during its first three years. Pruning trees during the dormant period tends to have an invigorating effect on the tree. Good for a young tree, not so good if you are trying to control size.

Gummosis on plum in summertime
Gummosis on plum in summertime.

Pruning of dead or diseased branches can be done anytime, however, the sooner the better. And don’t prune suckers in the winter. This insures they will grow back in the summer. Over zealous winter pruning can result in waterspouts so go easy at this time of year. Summer pruning, done in June or July, decreases size and vigor which helps to slow the growth of a tree.

Often I’m asked whether to paint a wound with sealing compound after pruning. This is no longer recommended as it encourages wood rot. A tree is best protected by proper pruning technique and timing. With this in mind, don’t prune during late spring or fall as a tree is most vulnerable during those times. When you cut away part of a plant, a would is left, susceptible to pests and diseases. To avoid trouble always prune so as to make small wounds, rather than large ones. Trimming a bud or twig produces a smaller wound than waiting until it is a large limb. Rubbing off a sucker bud leaves a smaller wound than if you want until it has a year’s growth or more.

My friends sticky amber gum oozing from her dwarf nectarine branch is the tree’s reaction to stress. Cankers or sunken lesions covered with gum may be caused by mechanical injuries, such as lawnmowers or pruning, insects, winter damage, sun scald, herbicide injury or various fungal or bacterial infections. Practice good sanitation by removing and destroying cankered limbs.

You can prevent or control many diseases and overwintering insects by applying a dormant spray this month. This can be the most effective spray of the season. Fungal diseases such as peach leaf curl, fire blight, scab and anthracnose as well as insects including aphids, San Jose scale, bud moth, leaf roller, coddling moth and whitefly larvae, mealybugs and mites can all be controlled.

There are several types of dormant sprays and all three types are considered organic. Lime-Sulfur or copper can be mixed with horticultural oil which smothers overwintering insects and eggs. This spray is good for all fruit trees except apricots which should be sprayed in the fall with copper and this month with horticultural oil.

Apply dormant spray when the temperature is above 40 degrees. Make sure you cover every nook and cranny of each branch and trunk until the tree is dripping and spray the surrounding soil. Spray only plants that have suffered from pests or disease. Sprays, even organic, can kill beneficial insects as well. Even though they’re organic, dormant sprays can be irritating to skin and eyes, Wear long sleeves and gloves and eye protection.

I hope I don’t find any pictures on Facebook of your plant pests or diseases but post away if you something wicked your way comes and I’ll try to help.