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Archive for the ‘Disease in the Garden’ Category

Sad looking tomato plants

I'm pretty sure these Rutgers tomatoes are supposed to be bigger than 2" in diameter!

I’m pretty sure these Rutgers
tomatoes are supposed to be
larger than 2″ in diameter!

My tomatoes are a disaster this year!

Their growth is slow and they are not producing many flowers or fruit. Plus, the fruit that has formed is way smaller than it should be. It’s very disappointing!

I planted about 40 plants which included 9 different varieties, most of which are heirlooms because they are so delicious. Normally by this time of the season, the plants would be lush and full and looming over the top of our 6 foot trellises. There would also be lots of beautiful full-sized tomatoes with many more coming on. Not so this year!

The season started out on a downside when, within a few days of planting out my transplants, we noticed some severe cupping and curling of the foliage especially on the youngest leaves. When I saw it I immediately thought – classic 2,4-D herbicide injury! I wish I had taken some pictures of the damage.

Tomato injury caused by 2,4-D

Tomato injury caused by 2,4-D

It affected all of the tomato plants. I also noticed 2,4-D injury on our grape vines which are growing on the hill above the vegetable garden. Tomatoes and grapes are especially sensitive to broadleaf herbicides. Even light exposures can result in injury to the plants. If an herbicide like glyphosate (Roundup) or one that contains 2,4-D or dicamba is applied in the vicinity of a vegetable garden, it can easily drift onto the plants. Herbicides can drift pretty far if caught by the wind! We hadn’t sprayed anything but we found out later that a neighbor had been spraying a product containing 2,4-D to control thistle in the field right beside our vegetable garden. The spray must have drifted onto our newly planted tomatoes.

Strike One!

 

The spindly vines have a lot of diseased foliage.

The spindly vines have a lot
of diseased foliage.

We planted our tomatoes and most of the rest of the garden on the 21st of May. June had higher than normal rainfall, often in the form of heavy thunderstorms. This wet weather led to disease problems, especially in our heirloom varieties which make up about 80 percent of what we grow. We always have some disease in our tomatoes that wipes out their lower branches but it never seems to affect their production much. This year it was much worse. I am pretty convinced that the herbicide injury weakened and stressed the plants and left them more susceptible to fungal diseases.

Strike Two!

 

Hornworm damage on the Better Boy tomatoes

Hornworm damage on these
small ‘Better Boy’ tomatoes

Though we never seem to have much insect damage on our tomatoes, we have had an occasional hornworm on the plants. So far this year, Eric has discovered two hornworms on the tomatoes but only after they had almost completely defoliated a couple of the plants and chewed a few of the tomatoes as well! They are well camouflaged and it took a bit of hunting before he found and squashed the two culprits. Hopefully there aren’t more lurking among the foliage.

Strike Three!

 

With all these strikes against them, the plants have suffered tremendously. The foliage is sparse and the stems are elongated and spindly. I think this is mainly due to the herbicide injury early in the season.

The 'Pruden's Purple' tomato on the right is deformed and cat faced but at least it is larger.

The ‘Pruden’s Purple’ tomatoes
are small and some are deformed.

Though the plants have slowly outgrown the damage and the new growth is fairly normal, the plants are stunted and few flowers are being formed. The fruit that has formed is mostly remaining very small. I harvested a few medium-sized ‘Cherokee Purple’ tomatoes but most were deformed with severe cat facing (another symptom of 2,4-D injury).

Some of the problem may be environmental, too. I have heard that other people are having similar issues with their tomatoes; slow growth and the production of very few tomatoes that are all small in size. It may just be a bad year for growing tomatoes!

Unfortunately, it doesn’t look like we will be harvesting very many tomatoes this year. We should have enough to enjoy fresh but I’m pretty sure we won’t get enough to can.

The pole beans are doing very well!

The pole beans are doing very well!

On the bright side, the pole beans are doing very well except for 2 or 3 poles where some critter has nipped off the lower leaves. The vines are still strong and producing lots of beans at the top. We planted Rattlesnake beans, a purple pole bean, and a new one for us – Lazy Housewife Pole Beans. Yum!

The cucumbers have also produced well this year. So far I’ve made 23 pints of my famous bread and butter pickles and still have plenty to slice up for my lunches and I’ve even given a bunch away! I’ll be making more pickles this weekend and freezing beans, too!

I’m just so sad about my tomatoes …

Until next time –
Here’s hoping your tomatoes are doing better than mine!

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Today is Arbor Day!

Celebrate! Plant a tree!

Show someone close to your heart that you really care about them by planting a tree in their honor or in memory of a loved one. One day it will grow to be a majestic tribute to that very special person!

A majestic oak silhouetted against the winter sky

Here are a few tips for planting trees.

 

Below is a post that I wrote on Arbor Day in 2012.

I thought I would share it today in honor of Arbor Day 2016!

 

Today is National Arbor Day!

Our new woodland garden replaces our front lawn!

Our new woodland garden replaces our front lawn! We planted a little pink dogwood, hosta, and several azaleas. Now it just needs some mulch.

It’s always the last Friday in April although some states recognize a different State Arbor Day that corresponds better with planting times in their state. Since Arbor Day was founded in 1872, it has been customary to plant a tree in observance of the holiday and on that first Arbor Day, it is estimated that about one million trees were planted.

As you celebrate Arbor Day this year, keep in mind that as important as it is to plant new trees, it is equally important to care for and protect the trees that are already growing in your landscape.

Damage to mature trees due to insects and diseases (many introduced from other countries) can be devastating to your landscape as well as the surrounding areas and adjoining forests. Diseases such as the Chestnut blight and Dutch elm disease and exotic insects like the emerald ash borer and the Asian long-horned beetle have killed tens of millions of trees across the U.S.

Chestnut blight canker on the stems of a young American Chestnut. Photo by Eric Jones

Chestnut blight canker on the stem of a young American Chestnut.
Photo by Eric Jones

The chestnut blight, caused by a fungus (Cryphonectria parasitica), was introduced to North America from Asia in the early 1900’s either on infected lumber or through diseased trees. Within 40 years of its introduction, virtually all the chestnut trees in North America were wiped out. Although mature American chestnut trees have disappeared from our forests, small trees often grow from stump sprouts since the blight doesn’t kill the roots. Unfortunately, these small trees rarely grow to reproductive age before they are attacked and killed by the fungus. Such a sad ending for these once majestic trees which often reached 200 feet tall and 14 feet across! There is no cure for this disease but much work has been done to genetically engineer a disease resistant American chestnut using genetic material from a few stump sprouts that managed to produce seeds and a bit of DNA (as little as 3%) from Asian species that show resistance to the blight. The American Chestnut Foundation is at the forefront of this research with a mission …

…to restore the American chestnut tree to our eastern woodlands to benefit our environment, our wildlife, and our society. The American Chestnut Foundation is restoring a species – and in the process, creating a template for restoration of other tree and plant species.”

How’s that for a great Arbor Day message!

Woolly adelgids on the branch of a young hemlock.

Woolly adelgids on the branch of a young hemlock. Photo by Eric Jones

Another pest that is doing its best to wipe out whole a species of trees is the hemlock woolly adelgid (Adelges tsugae). This past Sunday on a wonderful but rainy walk in the George Washington National Forest, Eric and I saw evidence of this destructive pest on a young hemlock. The hemlock woolly adelgid was also an accidental introduction from Asia and is devastating populations of eastern hemlock (Tsuga canadensis) and Carolina hemlock (Tsuga caroliniana) throughout eastern North America. The insect damages the trees by feeding at the base of the needles causing them to desiccate and eventually drop off. Heavy infestations have been known to kill trees in as little as four years but healthy trees can sometimes survive an attack for a longer period of time. Luckily, there are products that the homeowner can use to help control hemlock woolly adelgids but sadly in our hemlock forests, these pests are causing the destruction of large numbers of these beautiful trees. Read more about the woolly adelgid.

As they have with the American chestnut, researchers have developed an adelgid-resistant hybrid by crossing the Carolina hemlock with an Asian hemlock which is resistant. While this is great progress – it does nothing to save the trees that are already infected!

Seen these hanging around?

Seen these hanging around? These purple structures are Emerald Ash Borer traps used to evaluate populations of the pest.

Another group of insects that causes widespread damage to established trees is the wood-boring insects including the emerald ash borer, the Asian long-horned beetle (both introduced from Asia), and a wide variety of the bark beetles.

The emerald ash borer, first reported in Michigan in 2002, has already killed millions of ash trees and is a potential threat to all the ash trees in North America.

The Asian long-horned beetle is one of the most destructive of the wood borers because it is not selective and attacks a wide variety of hardwood trees.

Bark beetles, like the spruce beetle, the mountain pine beetle, and the southern pine beetle, have killed millions of conifers in North American forests especially during severe outbreaks.

Bark beetles attacked this weakened pine and contributed to its death.

Bark beetles attacked this weakened pine and contributed to its death.

I remember when we were in Alaska several years ago seeing where the spruce beetle had killed entire forests of Sitka Spruce. Although bark beetles generally attack trees that are weak, dying, or already dead, the species listed above are particularly destructive because they will attack live, seemingly healthy trees.

For the homeowner, there are products that can be used to help control some of these pests. Horticultural oils can help control the woolly adelgid if they are sprayed at the correct times.

Some systemic insecticides may help control adelgids, emerald ash borers, Asian long-horned beetles, and pine borers. Bayer Advanced 12 Month Tree & Shrub Protect & Feed II and Bonide Annual Tree & Shrub Insect Control are products that can be mixed and poured at the base of the tree according to the label directions. These products are not available in all states. Always read and follow the label directions when using any pesticides. Read more about borers.

On this Arbor Day, The Nature Conservancy reminds us of some important tips to help protect our trees.

  • Keep your trees healthy and vigorous! Many destructive insect pests and diseases are attracted to trees that are stressed due to poor nutrition, drought conditions, and mechanical injury such as lawn mower or weed whacker nicks in the trunk.
  • When purchasing trees, purchase certified, pest-free nursery stock.
  • To avoid inadvertently spreading invasive pests or diseases, NEVER transport firewood when you travel, always obtain it locally!

So make a pledge this Arbor Day to pay attention to your existing trees and strive to keep them strong and healthy!

… and plant a tree!

Until next time – Happy Gardening!

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Tomato harvest

Well, it’s that time of the year! The tomato questions are pouring in on our discussion board, Andre’s radio show, and over the phone and e-mails. At this point, the questions are mostly concerning problems with the foliage and just a few about the fruit.

One of the most recent discussion board posts brought up an issue that many gardeners may not be aware of …

“I have six different varieties of tomato plants planted in my raised bed. I noticed last week that the leaves had curled upwards. This week I noticed now that the leaves appear to be a little wilted as well as the blooms. The growth also seems somewhat stunted …

There are several things that can cause tomato leaves to curl but this combination of symptoms seemed consistent with herbicide injury.

Tomato injury caused by 2,4-D

Tomato injury caused by 2,4-D exposure

Herbicide drift can be a major problem for tomatoes because they are very sensitive to broadleaf herbicides. Even light exposures can result in injury to the plants. If an herbicide like glyphosate (Roundup) or a product containing 2,4-D or dicamba is applied in the vicinity of a vegetable garden, it can easily drift onto the plants. Herbicides can drift quite far when caught by the wind!

If they are exposed to only small amounts, the plants will usually survive and eventually outgrow the damage. Heavier exposures can be lethal.

Drift is not the only way that tomatoes can be exposed to herbicides.

  • If you spray your tomatoes with a fungicide or insecticide using a sprayer that has also been used to spray an herbicide, there may be herbicide residue left in the tank.
  • Herbicide damage can also occur if tomatoes are mulched with grass clippings from a lawn that has been treated with a weed and feed product or a broad leaf weed killer.
  • Lately, there have even been problems with plant damage resulting from mulches and compost that have been made from hay or manure taken from fields that had been sprayed with the herbicide Grazon.
Characteristic symptoms of glyphosate injury - yellowing at base of leaflets

Telltale symptoms of glyphosate injury –
yellowing at base of leaflets

In this case, as I learned from a later post, it turns out that a neighbor had been spraying herbicides in his yard and the drift had hit the tomato patch. Hopefully over time the plants will recover but flowering and fruit production may be delayed.

The bottom line:

  • Never spray herbicides in windy or breezy conditions
  • Use separate sprayers for herbicides and pesticides
  • Don’t mulch your vegetable garden with grass clippings if you have treated your lawn with a broadleaf herbicide

What else can cause tomato leaves to curl?

Physiological leaf roll is due to environmental stress factors

Physiological leaf roll is due to
environmental stress factors

Curled or rolled leaves can also be a physiological response by the plant to adverse weather conditions; too hot, too dry, too wet, too windy. The overall growth of the plant is usually not affected and the symptoms normally disappear when conditions improve.

Be careful not to over-water tomatoes. Overly wet soil conditions are often to blame for leaf roll.

Mulching your tomatoes will help maintain more even moisture content in the soil and also helps to maintain a more constant soil temperature.

There are several viral diseases such as curly top, yellow leaf curl, and mosaic virus that can cause curling of leaves, as well as stunted growth and pale leaves. There is no cure for these diseases and the plants cannot be saved.

Tomatoes with yellowing foliage and brown patches

Fungal disease is responsible for the majority of the tomato problems we face.

Fungal disease is responsible for the
majority of the tomato problems we face.

Some of the most common tomato problems are caused by fungal diseases. The tomato blights (early blight and late blight), as well as some of the wilt diseases and leaf spot diseases can be devastating to tomato crops. The first symptom is normally the yellowing of the older, lower leaves and branches.

Fungal spores that cause these diseases are found in the soil and on plant debris left in the garden. It is very important to rake up and remove old plants, fallen leaves, and rotting fruit from the garden at the end of the season. This important “housekeeping” task will help to reduce the incidence of fungal disease in the following season.

Mulching around your vegetable plants is another great way to reduce disease. This keeps soil (which may be filled with fungal spores) from splashing up onto the stems and leaves of your vegetable plants. Mulching the vegetable garden has so many benefits that it is worth doing every year!

If your tomatoes are showing signs of disease, prune off the diseased branches and throw them in the trash (do not compost them).

To prevent the disease from spreading to healthy foliage, spray the plants with a fungicide that is listed for use on edibles (Bonide Copper Fungicide, Mancozeb, or Fung-onil). Sometimes it’s good to alternate different fungicides.

Always read and follow the label directions!

Here are a few more tips to help you avoid (or deal with) tomato problems this season. Here’s to a great harvest!

Until next time – Happy Gardening!

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The rhododendron bald at Craggy Gardens

A few weeks ago, Eric and I took a trip down the Blue Ridge Parkway. We tried to time our trip to coincide with the rhododendron bloom in the North Carolina mountains, specifically at Craggy Gardens on the parkway just north of Asheville. While the native rhododendrons, Rhododendron catawbiense, were just beginning to show some color, the flame azaleas and mountain laurel were in full bloom. It was beautiful!

Mountain laurel in full bloom.

Mountain laurel in full bloom.

Azalea gall on native flame azalea

Azalea gall on native flame azalea

When we stopped to take some pictures, we noticed that a few of the azaleas had some strange growths on them that looked like some type of gall. It turns out that this was the azalea gall which is quite common on both native and hybrid azaleas. Catawba rhododendron is also quite susceptible. In fact, the majority of the rhododendrons growing on the rhododendron bald above the Craggy Gardens Visitor Center had at least a few of these unusual, fleshy galls.

I’ve written about galls on plants before but most of those I have talked about were galls that developed in response to insect activity.

Azalea gall has caused swelling and distortion of young leaf tissue of this native rhododendron

Azalea gall has caused swelling
and distortion of young leaf tissue
of this native rhododendron

The azalea gall, Exobasidium vaccinii, is caused by a fungus which infects the leaves, flowers, and branch tips of azaleas, rhododendron, and certain species of Vaccinium like blueberries and cranberries.

The fungus causes abnormal growth in the tissues that are infected. These swollen tissues form the gall and cause distortion of the leaves, stems, or flowers.

Azalea galls can be light green, pinkish, or (as we most often observed) white.

This pale green gall will become white once the spore layer forms

This pale green gall will become
white once the spore layer forms

During the late spring and early summer, a white spore layer forms on the surface of the gall. This may be why all the ones we saw were white. These spores are dispersed by wind or rain to healthy leaves or flower buds on the same or different susceptible plants. The fungus remains dormant in these tissues until the following spring when new galls form soon after the plant begins to grow. Once the spores are released, the gall begins to turn brown and eventually dries up and falls to the ground.

Cool, wet weather favors the dispersal of the fungal spores. Up on the ridge tops of the Blue Ridge Mountains where native rhododendron and azalea are prevalent, fog and misty rains are common in the spring and summer. These conditions are perfect for the spread of this disease.

The rhododendron bald at Craggy Gardens is enveloped in a misty fog

The rhododendron bald at Craggy Gardens is enveloped in a misty fog

A rhododendron flower is completely distorted by a gall

A rhododendron flower is
completely distorted by a gall

Though the azalea galls may look harmful, normally, they do not have an adverse effect on the plants. However, if cool, wet weather persists during the time of spore dispersal, the disease can spread more readily and result in the formation of many more galls the following spring. This can sometimes have a negative effect on the health and vigor of the plant.

Usually only a portion of the flower head is affected.

Often only part of the flower head
is affected by the gall.

Azalea gall is a common problem in many hybrid azaleas. Physical removal of galls is the simplest control method. Galls should be pruned out with shears before the white spore layer forms.

If galls are prevalent or conditions are favorable for the spread of the disease, fungicide applications may be warranted. Bonide Fung-onil or Bonide Mancozeb can be applied according to the label directions to control azalea leaf and flower gall. Begin applications just prior to bud break in the spring.

Until next time – Happy Gardening!

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Grafted melon at Merrick Farm, Wilbraham, MA. Photo: Megan Poljacik

When I first heard about grafted tomato plants several years ago, I thought the idea was crazy. I was very aware of the great cultural benefits of grafted trees and shrubs but why in the world would you spend the time and effort to graft a vegetable that only grows for a season then dies with the first frost?

Grafted tomato

Grafted tomato; Cornell University Cooperative Extension

It didn’t dawn on me at the time that the same disease resistance and increased overall vigor that the rootstock imparts to a grafted fruit tree could also work for a grafted tomato plant. When you think about it, this is a brilliant concept because tomatoes and many other vegetable crops have a plethora of disease and pest problems that we as gardeners are constantly battling.

It turns out that grafting vegetables is not a new practice at all – they’ve been doing it in Asia for a long time!

What is grafting?

Grafting involves taking the top of a plant (the scion) that has very desirable fruit qualities like superior taste (but low vigor and disease resistance) and attaching it to the bottom of a plant (the rootstock) that is known for its vigorous growth and disease resistance.

Getting ready to graft a melon (scion) to a gourd rootstock at Merrick Farm, Wilbraham, MA

Getting ready to graft a melon (scion)
to a gourd rootstock at Merrick Farm,
Wilbraham, MA  Photo: Megan Poljacik

One of the main advantages of grafted vegetables is their resistance to soil-borne pests and diseases.

Remember my whole diatribe on crop rotation? There are a lot of people with small backyard gardens that don’t have the space to rotate their crops. Planting grafted vegetables reduces the need for crop rotation. The rootstock that is used for the graft is selected for its resistance to a wide range of soil-borne diseases, including those that persist in the soil for many years. So even if diseases like Verticillium wilt, Fusaruim, bacterial wilt, or tobacco mosaic virus are lurking in your soil, grafted tomatoes are less likely to be affected because of their vigorous, disease resistant rootstock. You have a super plant!

Completed melon graft; Merrick Farm, photo: Megan Poljacik

Completed melon graft; Merrick Farm, photo: Megan Poljacik

What about diseases like early blight and late blight that travel to the plants via wind and rain? Are grafted plants protected from these devastating diseases? Unfortunately, these diseases attack the above ground parts of the plants – the foliage, stems, and fruit and the rootstock of grafted plants cannot directly provide resistance to these foliar diseases. However, as I have said many times before, healthy, vigorous plants are much less susceptible to disease and pest pressure.

An heirloom tomato grafted on a superior rootstock will theoretically be more vigorous, healthy, and productive than if it were growing on its own roots. The root system of the “super rootstock” will be much more extensive, thus providing more surface area for absorption of water and nutrients. This should lead to a healthier plant. Many of the grafted tomatoes that you will find are heirloom varieties. These very tasty tomatoes can be more prone to disease problems than hybrid tomatoes so grafting may offer a healthier, more productive plant.

Conversely, if a blight resistant tomato such as Defiant is grafted onto a hearty, disease resistant rootstock, you could end up with a seriously disease resistant tomato! Actually, this is a popular grafted tomato that is available!

Tips for growing grafted tomatoes

Grafted tomato planted with the graft well above the soil line.

Grafted tomato planted with the graft well above the soil line.

Remember how you have always been told to plant your tomatoes as deeply as possible because they will develop roots all along the buried stem and you will end up with a more robust plant? Deep planting is a no-no for grafted plants. It is extremely important to keep the graft above the soil line when you plant. If the graft ends up below ground, roots will develop above the graft, which totally defeats the purpose of having a grafted plant! When the scion roots into the soil, the disease resistance of the rootstock is bypassed and the plant is no longer protected. Money wasted! This may be the reason why some people are not successful with grafted plants and feel that they are not worth the expense to purchase.

Keep the graft at least an inch above the soil when you plant.

As the plant grows, provide it with a good support system to keep it off the ground. Any stems or branches that touch the ground can take root – again, bypassing the disease resistance of the rootstock. We grow our tomatoes on a trellis and keep all the side shoots tied up as well as the main stem. You can also tie them to stakes or a fence or grow them in cages – anything that keeps the plant from sprawling on the ground where it can take root.

It is also important to remove any growth that develops below the graft.

Many different vegetables are being grafted these days.

Melons are commonly grafted to improve disease resistance and yield.

Melons are commonly grafted to improve disease resistance and yield.

Although tomatoes are the most common, you can also find (or create your own) grafted peppers, eggplants, cucumbers, squash, melons, and watermelons. Each of these is grafted onto vigorous rootstocks that are developed specifically for that particular vegetable type and the specific diseases that attack it.

Grafted vegetables not only have increased vigor and resistance to soil-borne diseases but, because of the superior root system that develops in these plants, they also show an increased tolerance to environmental stresses like drought, temperature extremes, and nutrient deficiencies. The extensive root system increases the area that the plant can exploit for the water and nutrients needed for growth. The result is a healthier plant that not only bears well, but potentially requires less fertilizer, is drought tolerant, and has a reduced need for pesticide applications.

This may be the year that we give grafted plants a try. We may try to pick up a tomato plant or two at a local garden center. It will be especially interesting if we can find a grafted version of one of the varieties that I plan to grow from seed. That would be a cool experiment! I will keep you posted!

Until next time – Happy Gardening!

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Deep crack on the bottom of a large tomato. Black mold is beginning to grow in the crack.

It’s been a tough year for tomatoes.

The weather, at least in our area of the Shenandoah Valley, has been cooler than normal and fairly dry. The rain we’ve had has mostly come as heavy downpours – “frog stranglers” as my old boss used to say. We haven’t had many nice steady, soaking rains. Heavy rains, which are often associated with thunderstorms, are usually more destructive than helpful because most of the water runs off without soaking in and takes a lot of topsoil with it.

I saw on the news the other night that so far this summer, we’ve only had 15 days over 90° – the normal is 25 days by this point. Many days in July and August were in the 70’s and nights were often cool – in the 50’s and even several nights when the temperatures dipped into the mid to upper 40’s. Crazy! Nice for us but it has caused some issues in the vegetable garden.

Tomatoes don’t do well in cool weather – especially when the nights are cool. Temperature extremes (daytime temps above 90° or nighttime temps below 55°) cause poor fruit set.

First tomato harvest - 'Pruden's Purple' on July 6th and a nice big pepper, too.

First tomato harvest – ‘Pruden’s Purple’
on July 6th and a nice big pepper, too.

Our tomatoes started the season growing well; producing loads of flowers and setting lots of fruit. We have noticed that after this initial burst in June, everything slowed way down in July and August. We noticed fewer flowers and didn’t see many young tomatoes forming. The tomatoes that formed in June continued to grow and eventually ripened but production has certainly tapered off. I have heard the same complaint from other gardeners. This summer just hasn’t been favorable for growing tomatoes.

I have noticed several different problems on our tomato fruit this year but most of these are issues that I have seen in other years as well. They are fairly common tomato problems.

Growth cracks

These shallow growth cracks have healed over

Shallow growth cracks can heal.

Growth cracks develop in tomatoes when they undergo a spurt of rapid growth during ripening. This often occurs when extended dry conditions are followed by sudden heavy rain or irrigation. This isn’t an unusual situation and has occurred several times in our garden this season. As a result, many of our ripe tomatoes are showing varying degrees of cracking. Growth cracks frequently appear on the top of the tomato near the stem but sometimes when a tomato is fully ripe or overripe, cracks will develop on the bottom of the fruit. Shallow cracks will normally heal over but deeper cracks that develop can become easy pathways for disease and insects to enter and cause secondary problems.

Try to keep your garden soil evenly moist. Mulching definitely helps with this.

Anthracnose

Anthracnose lesion showing concentric rings of fungal fruiting bodies

Anthracnose lesion showing concentric
rings of fungal fruiting bodies

Anthracnose of tomatoes is a disease caused by the fungus Colletotrichum coccodes. It appears as sunken, circular lesions on ripe tomatoes. Often these lesions have concentric rings of black fruiting bodies in the center. Green tomatoes can become infected with anthracnose but the symptoms do not appear until the tomato ripens.

The fungal spores are found in the soil and on plant debris left in the garden. Tomatoes are infected when soil containing spores is splashed up onto the fruit and foliage.

Anthracnose has destroyed half of this tomato

Anthracnose has damaged half
of this tomato

Anthracnose does little damage to the leaves but can cause major damage to mature, ripe tomatoes. This disease is more common during warm, wet weather but spores can also be transmitted to the plants from splashing during overhead irrigation.

Mulching around your tomato plants and trellising or staking them to keep them off the ground will help to prevent this fungal disease. Avoid working among the plants when they are wet and harvest the tomatoes as they ripen and use them promptly.

Infected fruit should be removed to prevent the spread of the disease. Crop rotation and careful clean up of all plant debris in the fall is important for controlling anthracnose.

Cat facing

Cat facing on a large heirloom tomato

Cat facing on a large heirloom tomato

Ever find tomatoes that have funky-shaped, puckered bottoms? This is called cat facing and it is thought to result from the abnormal development of the flower bud or flower – before the fruit is even formed! The factors that lead to cat facing in tomatoes are normally environmental, including cool temperatures before and during flower formation. Hmmmm, that sounds familiar!

Other causes of cat facing in tomatoes are any type of physical damage to the flowers, herbicide damage (such as drift from nearby 2,4-D spraying), and sometimes excessive pruning of tomato plants.

Mild cat facing

Sometimes it isn’t too bad

.

Varieties that produce large tomatoes, such as beefsteaks and the large-fruited heirloom tomatoes, are more prone to cat facing than small-fruited varieties.

Normally, tomatoes that are disfigured from cat facing are still edible however they may ripen unevenly and they can be difficult to slice – I just chunk them up instead! Still delicious!

Black mold

Black mold started growing in the growth cracks of this tomato.

Black mold started growing in
growth cracks of this tomato.

Black mold is caused by various fungi (including Alternaria alternata) that attack tomato tissue that has been injured in some way. It is rarely found on healthy, unblemished tomatoes. The fungal spores usually enter the tomato where the skin has cracked or where insects have caused injury to the fruit. As the fungus grows, it creates brown or black sunken lesions which expand and eventually cause the whole tomato to rot.

If you catch it early, you can just cut out the bad patches but it’s important to remove all the soft tissue or the tomato will taste bad.

All of these problems have developed on at least some of my tomatoes this season. Fungicide sprays listed for use in vegetable gardens can help but I normally don’t bother with them. None of these diseases have caused any major damage to my tomato crop. We just harvest the blemished fruit, cut out the diseased parts, and eat them. You should NEVER can or freeze tomatoes that show signs of disease.

Even though our tomato crop hasn’t been a bust this year, the yield from our 36 tomato plants should have been much higher. I’m normally swimming in tomatoes at this point in the season. Well – at least the tomatoes we’ve harvested have been very tasty. I’ve been able to can a few batches so far and they are still coming along. Hopefully this hot spell we are in now will give them a late season boost!

Lynne's cherry tomatoes are beautiful but her other tomatoes are small.

Lynne’s cherry tomatoes are beautiful
but her other tomatoes are very small.

How did your garden do this year?

My sister Lynne in Vermont told me yesterday that her tomatoes are all really small this season compared to other years. It’s been unusually cool up there this summer, too!

She sent this photo of her recent harvest. Nice rattlesnake beans and cukes Lynne!

Until next time –

     Happy Gardening!

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Spindle galls on cherry

Galls on plants are funny things.

They come in all sizes, funky shapes, and crazy colors. There are thousands of different types of galls and they can be caused by insects, fungi, bacteria, mites, midges, or wasps. Galls can form on the leaves, buds, flowers, stems, twigs, branches, and even on roots.

Oak bullet galls

Oak bullet galls

Normally, galls are formed by the plant in response to some type of “alien invasion”; often from insect or mite feeding or egg laying. As bizarre as these abnormal growths appear, they do not usually interfere with the normal function of the plant.

A few years ago I wrote about two types of galls that are common on goldenrods; the bunch gall caused by the larva of a small gnat and the stem gall caused by the larva of the goldenrod gall fly. The goldenrod was still blooming and seemed otherwise unaffected despite the presence of these galls.

Oak trees seem to harbor several different types of galls, many of which are caused by tiny gall wasps.

Oak bullet gall with exit hole

Oak bullet gall with exit hole

This spring when I was walking around in our yard, I noticed a bunch of hard, round galls on some low branches of a young white oak tree. These galls are called oak bullet galls (or oak marble galls) and are caused by a gall wasp. The gall forms as a deformity of a leaf bud when the wasp lays an egg within the leaf bud tissue. The developing larva stimulates the growth of the gall which starts out as a round green mass and matures to a hard brown marble-sized gall later in the summer. The tiny adult wasp emerges in September through a small exit hole in the gall.

Oak apple gall developed from this oak leaf tissue

Oak apple gall developed
from this oak leaf tissue

 

Oak bullet galls are often confused with another common oak gall called the oak apple gall. Oak apple galls are quite a bit larger than the oak bullet galls. They too are caused by the feeding of a gall wasp larva. In this case, the gall actually develops from leaf tissue.

Like most galls, oak bullet galls and oak apple galls do not usually hurt the tree.

 

Wool sower galls are quite beautiful!

Wool sower galls are quite striking!

 

The wool sower gall is another strange gall that is only found on oak trees and specifically only found on white oaks. These puffy, round galls are caused by the larvae of another small wasp. They are really cool looking! Wool sower galls are sometimes called the oak seed gall because if you tease them apart, you will find tiny structures that resemble seeds in the center. The wasp larvae develop in these little compartments.

Spindle galls on a cherry leaf

Spindle galls on a cherry leaf

Another really funky looking gall is the spindle gall. Every year I see these weird growths on the leaves of some of the wild cherry trees in our woods. Talk about something out of a sci-fi movie! These colorful, finger-like galls are caused by microscopic mites called eriophyid mites. The galls form in early spring when the leaves begin to expand and the tiny mites begin feeding on the leaf tissue.

Spindle galls on a maple leaf

Spindle galls on a maple leaf

The upper surfaces of the leaves become covered with these crazy looking pink, red, or green spindle-shaped projections. It looks like some terrible rash! Believe it or not, the growth of these spindle galls has little effect on the health of the trees. Spindle galls are common on maples as well as cherries.

Galls caused by one of the spruce gall adelgids

Galls caused by one of the
spruce gall adelgids

Adelgids are devastating pests of many conifer species. Woolly adelgids have decimated huge populations of Eastern hemlocks and Fraser fir in the eastern part of the United States.

Several adelgid species, including the eastern spruce gall adelgid and the Cooley spruce gall adelgid, produce galls in various species of spruce. Unlike the woolly adelgids, these adelgids generally do not kill the trees unless there are repeated infestations which can eventually weaken the trees. Normally the damage is limited to the tips of a few branches, but in the landscape, these brown tips can be unsightly.

A mature cedar-apple rust gall erupts into mass of bright orange tendrils after wet weather in the spring.

A mature cedar-apple rust gall with bright orange tendrils

Cedar-apple rust is a fungal disease that produces weird galls on eastern red cedar trees. I’ve written about this double-host disease before. During wet weather in the spring, these galls sprout gelatinous tendrils full of fungal spores which are carried to the alternate host, apple or crabapple trees. Here they cause damaging rust disease on the leaves and fruit. The galls on the cedars cause little damage to those trees but the apple and crabapple trees can be heavily damaged if they are not protected with fungicides.

 

Well – that’s a little bit about some of the funky growths that you may encounter in your landscape!

Normally, chemical control is not warranted or even very successful with these galls, EXCEPT in the case of the adelgids and the cedar-apple rust. Adelgids can be controlled with Bonide All Seasons Oil and the cedar-apple rust can be controlled on apples and crabapples with Bonide Copper Fungicide.

Until next time – Happy Gardening!

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