Tag: gardening

Who’s Camping in my Tree? Eastern Tent Caterpillars

eastern tent catipillars in webbing like tentThese guys are often confused with fall webworms, and bag worms, although all three are quite different. Eastern Tent Caterpillars (ETC) nests are active early in the season while webworms are active late season. ETC like to make their tent nests in the forks of branches, while webworm nests are located at the tips of branches. Fall webworms also enclose foliage or leaves within these nests. Tent caterpillars do not. Bag worms are single worm homes made of the foliage from the tree it has decided to call home. They mostly evergreens like junipers or arborvitae. I like to remember the difference like this… A bag can hold one, but a tent can hold many.

eastern tent catipillars in webbing like tentETC like wild cherry, other ornamental fruit trees, ash, willow and maple trees. They tend to make their tents on the eastern side of the canopy to take advantage of the early sunlight to warm them and start their digestive systems. After a about five instar, they fall from the tent, make a cocoon and after two weeks, the moth emerges. Mating occurs and the female deposits her eggs on the tree bark. Soon the eggs change into larvae, without leaving the egg and overwinter this way. In the spring, they emerge from the egg.tent catapillar netting

Other than their webs making trees appear unsightly, ETC rarely cause major problems unless their numbers become high. They are easy to control by waiting until nightfall, when they tend to go back to the tent and pruning the branch off. It can be disposed of via the garbage or campfire. If pruning is not an option, maybe these are:

  • Scrape off, discard overwintering egg masses.
  • Tear the protective tents out by hand before the larvae start to feed.
  • Control caterpillar movement and restrict access to feeding areas with Sticky Tree Bands or Tanglefoot Pest Barrier.
  • Apply Bacillus thuringiensis (Bt-k) or Monterey Garden Insect Spray (Spinosad) to the leaves to kill feeding caterpillars.
  • If necessary, spot treat with plant-derived insecticides as a last resort. Spray must penetrate silken tents for effective control.

© The Naturarain

Four Letter Words For the Four-Lined Plant Bug (Poecilocapus lineatus)

four line plant bugs eating a leafThe four-lined plant bug (Poecilocapus lineatus) removes plant’s chlorophyll via their piercing-sucking mouthparts. They also secrete a toxin in their saliva that digests the components responsible for holding the plant cells together that leaves a hole in the plant’s epidermis. This feeding produces white, dark, or translucent spots the plant’s leaves, which can run together forming large blotches. Leaves can turn brown, curl-up and ultimately fall off. If feeding occurs on new growth, wilting may result.4 lines plant bug

Damage that the four-lined plant bug inflicts can be misidentified as a fungal disease spots because of the similar appearance and timing. Many times the bug isn’t seen during scouting, as when they are disturbed, the four-lined plant bug will drop to the ground or will hide on the other side of the stem. These are the same tactics asparagus beetles employ.

How to mitigate the damage:

These bugs do like a wide variety of plants, so be aware that the damage may look just a bit different on different plants. Unless the attacked plant is very small or having the new growth chewed, most plants will pull though with some damage. Scout the damaged plant at different times of the day. Sometimes bugs don’t wake up early in the morning!

four line plant bug damage

Have a cup of soapy water ready for when you do see one. They are easy to catch, place cup below them, wave your hand near them and they will cannonball into the soap water. No squishing required. Neem oil can also be used for bad cases.

During the fall, the banana shaped eggs are placed at right angles in vertical slits along the plant’s stem. The eggs will over winter and hatch in May to late-June. Therefore, removing the dead plant material at the end of the season will lower next season’s attacks.

© The Naturarian

Does My Elm Have Dutch Elm Disease?

A fungus called Ophiostoma ulmi that was introduced to the U.S. in the early 1930’s causes Dutch Elm Disease (DED). The American elm (Ulmus americana) is highly vulnerable and the disease has killed hundreds of thousands of elms across North America. All native elms are susceptible, as are European elms. However, the Asiatic elms, (U. parvifoli) and Siberian elm (U. pumila) are highly resistant to the disease.

The DED fungus is spread by two insect vectors: the native elm bark beetle (Hylurgopinus rufipes) and the European elm bark beetle (Scolytus multistriatus). The fungus is transported on the beetles from infected trees to healthy trees as they feed on twigs and upper branches. The beetles lay their eggs in the bark and wood of stressed trees along with elm firewood with the bark left on. Developing larvae form channels just under the bark and the fungus grows through the galleries until it reaches the tree’s water conducting cells, or xylem. Chemicals manufactured by the tree during its effort to fight the disease plug up the xylem, causing the tree to wilt.  In the Midwest, beetles typically have two generations per year.

DED is also transmitted through root grafts. A root graft happens when the roots of two trees intermingle and touch. Root grafts between trees are especially widespread in cramped urban street trees. Driveways and sidewalks are usually not effective in blocking root grafts, however, the disease usually does not spread in this manner beneath roads because road foundations are much deeper.

DIAGNOSIS:

elm branch showing the effects of dutch elm disease

During the early summer is when effected trees are the easiest to identify. Leaves on the upper branches will curl and turn a gray-green or yellow and finally, crunchy brown. This symptom is called “flagging”, although a flag alone is not complete assurance that the tree has DED. Another symptom is brown streaks in the sapwood beneath the bark of affected branches, which is the blocked xylem. However, only laboratory isolation and identification can positively confirm that the tree has DED. Check with your local extension or State University, usually they will perform this test for a nominal fee. Most arborists find these two symptoms are enough evidence to treat or remove an elm.

There are two other diseases that may look like DED, Elm Yellows and Bacterial Leaf Scorch. Below is a symptom checker:

Dutch Elm Disease Bacterial Leaf Scorch Elm Yellows
Caused by fungus Caused by bacteria Caused by phytoplasma
Affects individual branches first. Affects lower crown nearest root graft. Damage initially observed on single branches, and spreads to entire crown; oldest leaves affected first. Affects the entire crown at the same time.
Leaves wilt and turn yellow, then brown. Leaves brown along margin, with a yellow halo. Leaves turn yellow and may drop prematurely.
Symptoms often observed in early summer, however, could be anytime during the season. Symptoms appear in summer and early fall. Symptoms visible from July to September.
Brown streaking in sapwood. No discoloration in sapwood. No discoloration in sapwood.
No discoloration in inner bark. No discoloration of inner bark. Tan discoloration of inner bark.
No wintergreen odor. No wintergreen odor. Wintergreen odor in inner bark.

 

MANAGEMENT:

Elm tree with dutch elm disease

  • Branches infected with DED should be removed the same year the infection started. All infected branches should be pruned at least 5 feet, preferably 10 feet, below the last sign of streaking in the sapwood. Dip pruners often (best after each cut) in a solution of 10% bleach to prevent spreading the disease. Be sure to remove infected branches before the disease has moved into the main stem of the tree.
  • Trees with many branches infected with DED should be removed. There is no cure. The best thing to do to stop the spread of the disease is to promptly remove the tree.
  • Wood from DED infected elm trees need to be buried, burned, debarked, or chipped. When chipping and composting, temperatures must attain at least 120F. Cut logs from diseased trees should not be stored for firewood unless it has been debarked and there is no evidence of beetles.
  • Neighboring elm roots need to be severed with a vibratory plow or trencher before the infected tree is removed in order to prevent the movement through root graphs.
  • Choose cultivars that are resistant to Dutch elm disease. ‘Frontier’, ‘Homestead’, and ‘Valley Forge’ are a few that are offered in my area, but there are many more.
  • Healthy elms can be treated with a preventative fungicide injection to protect trees from infection by beetle feeding. Although, fungicide injections are not effective in averting infection through root grafts. Injections can only be done by a trained arborist and depending on the chosen fungicide, must be repeated on a 1-3 year cycle.
  • The consensus on treating the beetles with insecticide is not to. Contact insecticides require repeated applications during the growing season that may kill beneficial or harmless insects. Sanitation is by far the best way to control beetle populations.

Sadly, this is a prime example of what happens when we plant a monoculture of trees. Diversity is where it’s at!!

© The Naturarian

Salvias – Sage

These are very versatile plants. Members of the mint family, thus the interesting square stems. These have a long blooming time of May through October in shades of purple and pink. Salvia love sun and are fairly drought tolerant after about a year of establishment. The do like drained soils, so no wet sites. Mints tend to be deer resistant, for those who share their space with these guys. If cut back after flowering, a second flush of blooms will follow. Sweet!

salvia plant called sage

From Left to Right:

‘Marcus’ – short, compact plant with deep purple flowers ‘Sensation Rose’ – very short, dark rose florets with dark stems ‘Eveline’ – tall type with large, light pink florets, ‘Blue Hill’ – clear, lilac blue

salvia plant

From left to Right:

‘East Friesland’ – Stiff, upright wands of purple ‘May Night’ – Freer-form purple ‘Caradonna’ – Tall, stiff, darkest purple stems that stay showy even after blooming.

© The Naturarian

How to Get Rid of Euonymus Scale

euonymus scale

Edward L. Manigault, Clemson University Donated Collection, Bugwood.org – See more at: http://www.forestryimages.org/browse/detail.cfm?imgnum=1225115#sthash.fE97Hbiu.dpuf
Edwar

Euonymus scale (Unaspis euonymi) is a pest that is around all year, especially on groundcover euonymus. Treatment should be done when the crawlers emerge, which is around the early part of June, although it may be a bit later this year. Male adult scales are white, and females are dark brown and are shaped like an oyster shell. Euonymus scale overwinters as a mated (pregnant) female on the plant stems. Eggs develop beneath the scale and hatch during late spring.

Hatch times coincide with the blooming of:

  • Chionanthus virginicus – White Fringe Tree
  • Crataegus crusgalli –  Cockspur Hawthorn
  • Cornus alternifolia – Alternateleaf Dogwood
  • Syringa vilrosa – Lilac
  • Catalpa speciosa

Management: Pesticides won’t help until the crawlers emerge, but if the population is heavy now, prune out the infested branches to reduce the number of scales. Then, when it is time to use an insecticide it will be more effective. Since there has been a lot of winter damage on ground cover euonymus, pruning will be required to remove the dead branches and take care of two problems at the same time.

Horticulture soap* or oil will work to kill the crawlers.

*Please remember that you can’t make horticulture soap out of today’s dish soaps. Yes, back in the day, when soap was manufactured out of fats, it could be done. However, now they are all detergents, lacking the fat factor necessary to kill the insect.

© The Naturarian

Summer Annual Pots

shade annuals in pot
Summer Annual Container

If you’re looking for sensational summer color, look no further! Summer pots are the way to go. Not only are they full of pizzazz, the color is often right in your face, literally, especially if your favorite container is on a pedestal.

You don’t need to remember a bunch of annual names. The only thing you need remember for a well-presented display is: Thriller, Filler & Spiller! The Thriller is that one large plant that is generally in the center and taller than the rest. Filler are those mid-range sized plants, often of ‘fatter or fuller’ stature. Spiller is just that, plants that hang over the edge of the pot.

Here’s where your imagination needs to run free through the flowers. In many of the containers below, the photos are of the plants after there has been a bit of growth put on them. You can also get instant height from a trellised plant such as a mandevilla, jasmine or other vine.

Another tip ~ Flowering can be increased if the plants are kept on the drier side. This takes a bit of skill, as you don’t want them to dry-out, but keep them on the brink of drying. Why?!? Because. Think of it this way. If you’re kept all fat and happy without doing anything, why not just enjoy the hand-outs? (can you say ‘vegetative growth’? Haha!) Just like some of the folks living off us tax-payers, yet they have nicer stuff than me. =-( However, if you need to work for everything you’re getting, you fight to survive and multiplying is surviving in a plants eyes. Thus, more blooms = more seeds. Boom.

 

Contact us to get on the schedule!

© The Naturarian

Why Bulbs Aren’t Happy Looking Up Annuals Butts…

orange tulipsI was asked by a client the other day if we could plant her annual flowers right over her tulips, with the intent to allow the bulbs to ‘multiply’. I had to pass on bad news. Bulbs and annuals don’t play nicey-nice together. At least not with the selection we have here in the Midwest…

  • Bulbs should be planted at the correct depth for the bulb. If a bulb is planted too deep, to make room for the annual above, it may not grow.
  • Tulip foliage must be allowed to die-back naturally and will make an annual display look a bit messy until the foliage has died back and been removed. If you must prune the leaves back, there’s very little chance you’ll see tulips next Spring.
  • Bulbs, tulips in particular, do not multiply*, rather they disintegrate over time in the ground unless removed after the foliage has died back naturally, are stored properly and replanted in the fall. (Side note: Tulips give 3 years of service, in my opinion.)
  • Annuals planted over bulbs will remove all the nutrients from the surrounding soil leaving the bulb starved.
  • Bulbs need dry conditions, if annuals are planted above bulbs they will rot from the added water annual flowers require.

*Daffodils do multiply, however all the rest of the conditions would not be good for daffodil bulbs either.

 

© The Naturarian

Are My Plants on Crack? Powdery Mildew on Plants

mildew grape leaf.JPG
On grape leaf – Credit: David B. Langston

There are many species of fungus that cause powdery mildew on plants. Most only infect the leaf surface or stems and do not attack the leaf tissue of the host plant. Powdery mildew is not usually a serious problem, but to avoid severe damage to plants, quick control methods need to be taken.

Symptoms of powdery mildew:

Powdery mildews are observed in late spring and early summer as a white or gray powdery growth on leaves, stems, flowers, and fruit. As the fungus developments, buds fail to open, leaves can become distorted, turn yellow, brown or become chlorotic, or may drop prematurely. Fruits may develop blemishes or abort early.

white mildew on peony leaves
Powdery mildew on peony

Powdery mildew grows predominantly on leaf surfaces and does not require water to infect the plant. Powdery mildew fungi overwinter in tiny black bodies called fungal threads, which can be found in leaf litter, twigs, and dormant buds. In Spring, the fungal threads produce spores that start the cycle, especially during periods of high humidity when days are warm and nights are cool, ideal temperatures range between 60F to 80F. Vulnerable plants are most susceptible while new shoots and leaves are expanding. Fungus is host specific, meaning the powdery mildew on phlox does not infect crabapples.

 

How to manage the mildew!

Cultural

Many powdery mildews, especially those that attack woody plants, are more unsightly than destructive. Good sanitation is highly important to reduce infections the next season. Powdery mildews can hibernate through the winter on dead and living plant tissue.

  • Be proactive and purchase disease resistant plants.
  • Space the plants properly, in-well drained soils where plants receive good air circulation.
  • Dispose of diseased leaves as soon as they drop.
  • Do not compost or use as mulch.
  • Always avoid working among plants with wet foliage. Stay inside on rainy days!

Chemical

Since most powdery mildew symptoms occur late in the growing season, it is usually not considered serious enough to justify chemical control. However, some plants may warrant protection and successful chemical control requires applying a fungicide properly and at the right time. Fungicides are a prophylactic, meaning it has to be sprayed on the plant before the infection occurs. Depending on what species or part of the plant (leaves, flower or fruit) you are trying to protect, spray times may be different.

One of my favorite, efficient fungicides to use is the Bordeaux mixture. In the early 19th century, many of the European grape vines were infected with blight caused by the aphid Phylloxera vastatrix (argued to have come from American grapes), but also mildew and other diseases caused by fungi.

In 1885, botany professor Pierre-Marie-Alexis Millardet of the University of Bordeaux studied powdery mildew in the vineyards of the Bordeaux region. He noticed the vines sprayed with copper and lime to keep nibblers away along the roads showed no signs of the disease. To this day, his solution is widely used in vineyards.

© The Naturarian

Epic Fail in My Landscape

dead shrubsIn 2017, I designed and installed a whole new front foundation bed. It took almost a year for me to even design it, as I wanted to find the most obscure plants for my garden. No ordinary plants for me!!

I noticed a new plant being offered at a few nurseries of mine called First Editions® Amber Jubilee® Ninebark or it’s original name, Physocarpus opulifolius ‘Jefam’. Basically, Monrovia bought the rights to ‘Jefam’ and changed it’s name to patent it.

Common Ninebark’s are native here, so I didn’t question the hardiness of this shrub. I thought it’s orange leaves in this variety would be a wonderful addition to my landscape.

Sadly, this spring they barely leafed out. All five shrubs are toast. At $45 a pop at wholesale, that was a hit to my pocketbook. Hubby will be doing me the pleasure of removing them. I’ve decided large perennials would be a better choice for this location. We will be painting the house next spring and they will be safe underground opposed to these shrubs next to the house. The replacement cost is five times lower, also.

So, what happened here!?!

Well. Here are a few thoughts that ran through my mind:

  • They were planted at the correct depth, mulched and watered correctly.
  • They were planted in the correct exposure, 6 hours of sun.
  • There wasn’t an herbicide accident or outside force that took them out.
  • No animal damage.
  • Yes, sometimes things just die.

As a horticulturist, I do take this personally. I don’t understand how something can just die on my watch! I do know there are forces in nature that we as humans can’t understand yet. I get it.

The thing I did find interesting is that these plants started being advertised by Monrovia in 2014. I’m not sure how long the original ‘Jefam’ had been around. In 2017, nurseries were full of them. This year, they aren’t listed in any of the inventories. This tells me that the plant wasn’t popular or didn’t over-winter well at the nurseries. If a nursery can’t keep a plant alive, who could?

In the end, I figured my story would make non-professional gardeners feel better. Things do die in the landscape, even under the watchful eye of an educated horticulturist.

PS – I wrote this post before I ripped them out of the landscape and didn’t want to do a whole rewrite…

There is another possibility/reason they croaked. Their root systems were very week and undeveloped, a nursery management issue. Nurseries sell by pot size and actual size. Most likely the nursery had many orders for these and sold them sooner than they should have from a recent upsize in pot. Immature plants with under-developed root systems survive just fine under drip irrigation and climate control. Once out in the real world (like kids after college), they don’t realize how tough the real world is. These ripped out of the ground with little effort, as the rootball was only he size of a softball. It should have been the size of a basketball, at least.

© The Naturarian