Helga George

In the 1880s, a new disease decimated vineyards in the Los Angeles basin. California’s first professional plant pathologist, Newton B. Pierce, studied the disease and was rewarded with its being named after him.More than a century later, Pierce’s disease is still a major threat to vineyard

Many fruit, nut, and landscape trees can succumb to root rot caused by three types of fungi and a group of water molds (that used to be considered fungi); these include the fungi Armillaria, Phymatotrichum, and Xylaria and the water mold Phytophthora.The trees show varying symptoms from these different di

What could be wrong with an attractive, compact, bushy peach tree? Plenty! Your tree could have the incurable bacterial phony peach disease (PPD).This disease came seemingly out of nowhere and first struck peach trees in Georg

If you live in a temperate zone, chances are that you have encountered powdery mildew in your garden.Powdery mildew is a worldwide menace, with hundreds of specie

There are few things more beautiful than lush hydrangea bushes. Unfortunately, their beauty can be sullied by a number of fungal and viral diseases (and two bacterial diseases).However, there are steps you can take to k

Raspberry fruitworms, also known as raspberry beetles (or raspberry fruit worms), are members of a small family of beetles known as the Butyridae.The damage caused by these beetle

Trichoderma is a genus of soil-dwelling fungi found all over the world that are highly effective at colonizing many kinds of plant roots, and inhibiting fungi that cause many types of diseases. It was one of the first types of biofungicides commercially available.One strain in particular, T. harzianum T-22, is

Hopefully you don’t think of soil as just dirt.Soil is actually an incredibly complex ecosystem, with billion

Hellebores herald the arrival of spring, often blooming as early as January with delicate cup-shaped flowers in a wide variety of colors.These evergreen perennials don’t usually

Tomatoes are a much-loved summer crop, but everyone from the newbies to the most seasoned green thumbs may discover a problem or two afflicting their plants.So, what’s a gardener to do?Our guide to the most

Gray mold, also known as Botrytis fruit rot or Botrytis flower rot, is one of the most difficult strawberry pathogens to control if the environmental conditions are right for infection.Unfortunately, the fungus that causes this disease, Botrytis cinerea,

If you grow tomatoes, you have almost certainly run afoul of the fungus that causes the disease known as early blight.This ubiquitous tomato disease

At some point you’ve probably noticed tiny little piles of sand and soil next to pavements, sidewalks, or near the edge of buildings. This displaced dirt is likely to be the handiwork of pavement ants.Although originally from Europe, these pavement

Referred to as timber rot, white mold, or sclerotinia stem rot, this disease can wreak havoc on tomato plants in cold, wet climates, and may persist in the soil for up to 10 years.And it’s not only your tomatoes that may be at risk. White mold can infect

Are parts of your plants covered with black splotches or a dark coating?If so, it’s possible they are suffering from

You may know that many plants don’t grow well – or at all – under walnut trees. This fact has been observed and documented since the first century AD.But what about pecan trees? Do they h

Imagine this scenario with me: you’re examining your fruit trees, several that you’ve been growing for years.Much to your horror, most of your apples have come down with

Vespula pennsylvanica / maculiforna / germanica / vulgaris / squamosa and DolichovespulaThe dog days of summer…fresh water melon, ice cream, p

You nurture your tomato plants until you have beautiful fruit maturing on the vine.Upon closer inspection, you discover that somet

If you live in the Mid-Atlantic, you have almost surely heard of the dreaded spotted lanternfly (SLF), known scientifically as Lycorma delicatula.This invasive planthopper originated from China, where it was

Late blight is a serious disease that may affect tomatoes and potatoes. It can rapidly destroy entire fields and ruin a farmer’s income for the year. And it may affect crops in home gardens severely as well.You may not realize it, but you are probably already familiar with the

If you’re anything like I am, it’s easy for you to fall in love with a new plant, sometimes based on its picture alone.For me, bergenia is such a plant. I find it difficul

Colorado potato beetles pose such a grave threat to potato crops that flamethrowers have been used to control them. However, you do not have to go to such extremes in your garden.We at Gardener’s Path provide a number of natural control methods to use ag

Although kale plants are usually extremely healthy and rarely contract diseases in a home garden, sometimes they can suffer from infections.Your best way to prevent this is to keep your pl

Hydrangeas can be lush, carefree plants, but they are also vulnerable to a number of different fungal infections that can sully the leaves – and in some cases, the flowers.You know that old saying, “There’s a fungus among us?” There is some truth to t

Rusts are fungi that will not kill their hosts, although they sure make them suffer. There is even a term for pathogens that require living hosts: biotrophs (in contrast to necrotrophs, pathogens that kill their host and live off the dead tissue).Think Gloria Gaynor – your plants will survive! However, repeated infections of this pat

Gummosis refers to the oozing of sap or gum from a tree. This behavior is very common on stone fruits, including apricots, peaches, and plums.You can look at gummosis as your tree’s cry for help in the face of any one of a number of problem

The squash bug is a pernicious insect, one of the most common and serious pests of cucurbit plants like squash and pumpkins, as well as cucumbers and melons, though typically to a lesser degree.Unfortunately, these bugs are widespread throughou

Peace lilies, Spathiphyllum spp. are easygoing houseplants that seldom suffer from disease issues when provided with the right care.In fact, they are so easy to grow that Dr. Leo

No doubt you are familiar with pervasive bacterial soft rots of produce in storage – some of the most damaging diseases throughout the world.While potatoes are the most high-profile victims of

Walnuts have entranced societies for thousands of years with their beauty and shade – not to mention their delectable and extremely healthy nuts and valuable wood.However, there is a dark side to growing walnuts, and it comes

Bacillus amyloliquefaciens (BAA) is a type of bacterium that is found in soils throughout the world and also on dried foods and fresh produce.Many strains of these bacteria enhance plant growth and inhibit plant pathog

Two species of the fungus Alternaria, A. brassicicola and A. brassicae, can cause leaf spot on turnips.You will know that you have Alternaria leaf spots on your turnip or rutubaga leaves when t

Bot rot, also known as white rot, is caused by the fungus Botryosphaeria dothidea. Infection can result in a complex of diseases – two types of fruit rot and cankers on the limbs and twigs.This pathogen infects not only apples and crabapples but also a number

Is this a familiar scenario? You get up after a good night’s sleep and check your garden. It looks like there are notches on your bergenia leaves that weren’t there yesterday. Could that be…?While bergenia is generally resistant to pests,

While the name Phytophthora might not mean much to you, these organisms are a menace to agriculture and forests alike.The name is derived from Greek and tells you what you need to know about them:  p

While powdery mildews don’t kill their hosts, they sure do a number on them. And that is particularly true for powdery mildew of apples and crabapples, caused by Podosphaera leucotricha.This pathogen attacks both cultivated and wild apples