• Aug 24

by Karen Weiland, Advanced Master Gardener

There are several advantages to growing your own herbs.  One is being able to harvest fresh herbs for cooking and another is the ability to have specialty herbs that may not always be available at your local market.  Drying herbs is a wonderful way to save your fresh harvest and extend the use of your garden into the winter months.

The best day to harvest is a rather dry, sunny one and should be done in the morning after the dew has dried from the plant and before it gets hot.  Herbs grown for their foliage should be harvested before they flower and have not been treated with a pesticide that has not been cleared for use on herb foliage that will be eaten.  Herb flowers have their most intense oil concentration and flavor when harvested after flower buds appear but before they are fully open, so collect herb flowers just before full flower.  Harvest herb roots in the fall after the foliage fades.

Annual herbs can be harvested until frost.  Perennial herbs can be clipped until late August, early September.  Stop harvesting about one month before the first frost date.  Pruning late into fall could encourage new growth that will not have time to harden off before winter.

The plant will need enough foliage to re-grow after harvesting, so for a mid-season harvest do not take more than one third of the plant foliage.  Check the picked foliage for insects, eggs or leaf damage and rinse in tepid water if needed, pat dry with a paper towel.

There are several ways to preserve fresh herbs.  Some methods may be preferable over others depending on what type of herb you are preserving.

Drying herbs concentrates the flavor so you may only need to use one third to one fourth the amount of fresh herbs in a recipe.  To prepare for drying, remove any foliage near the base of the stem and tie twine around 6 to 7 stems to form a bundle.  A rubber band works well too as it contracts as the stems dry.  Hang in a cool spot that has good air circulation and is not in direct sunlight.  You can dry individual leaves on a screen, turning them frequently.  Dry until leaves and stems are crisp.  You can then store them “as is” on the dried stem or remove the leaves and place them in a jar or plastic container with a tight lid .  Store dried herbs in a dark, dry location away from any heat source.  Airtight storage will preserve aroma and flavors the best.  If needed, an old sock can be placed over the jar to prevent light infiltration.

Freezing is another method of herb preservation.   Place the prepared herbs on a baking sheet that has been lined with waxed paper then place it in the freezer.  Young stems with the leaves can be frozen as a unit and herbs such as chives can be snipped into ¼ inch pieces, frozen, then transferred to a plastic bag and used by the spoonful as needed.  Chopped herbs can be placed in ice cube trays with some water, then after the cubes are frozen transferred to plastic bags and stored in the freezer.

As always, Happy Gardening!

More information about gardening and related subjects is available online at www.hort.purdue.edu/ext/garden_pubs The Purdue University Cooperative Extension Service can be reached at 499-6334 in LaGrange Co., 636-2111 in Noble Co., 925-2562 in DeKalb Co. and 668-1000 in Steuben Co.

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  • Aug 17

by Karen Weiland, Advanced Master Gardener

Our turf grasses are prey to numerous disease and pest infestations. One fungal disease called rust , occurs almost exclusively on Kentucky bluegrass and perennial ryegrass.  Although it is mostly a cosmetic issue, the easily dislodged orange spores can be a nuisance by covering shoes, pets and lawn equipment with a rusty residue.

Rust infected grass looks like it has a yellowish-orange hue.  When grass blades are inspected closely, they will be coated with yellowish-brown to orange-red spores or dust and can be easily rubbed off with a finger.  These spores, carried by the wind, shoes or equipment, spread the disease to other areas during the growing season.

Outbreaks of this disease are most common in late summer and early fall.  Low fertility (in particular nitrogen) and low water availability slow down turf growth allowing rust to develop. Formation of the spores also often occurs during seasons with excess rain which can lead to depletion of available nitrogen. Warm, cloudy, humid conditions followed by bright hot sun also contribute to the formation of rust spores.  Rust outbreaks require moderate temperatures (50 to 60 degrees F) and long evening dew periods (more than 10 hours).

Rust can be managed with attention to plant nutrition and regular mowing habits.  Apply small amounts of nitrogen fertilizer (two tenths to half a pound per 1,000 square feet) in chronic trouble spots (shaded and possible compacted areas) to help control the disease.  The nitrogen will promote leaf growth and allow for regular mowing, which helps the turf outgrow rust’s rather slow infection cycle.  Avoiding irrigation during the early evening will help limit disease spread by lessening the chance of extended dew periods.  It also never hurts to have a soil test done, paying attention to phosphorus and potassium levels.

When cultural practices fail to quell an outbreak, a single application of a fungicide can be used.  For the best result it is recommended that a professional lawn care service be used.

As always, Happy Gardening!

More information about gardening and related subjects can be found online at www.purdue.edu/ext/garden_pubs The Purdue University Cooperative Extension Service can be reached at 499-6334 in LaGrange Co., 636-2111 in Noble Co., 925-2562 in DeKalb Co. and 668-1000 in Steuben Co.

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  • Aug 11

by Karen Weiland, Purdue Master Gardener

Planting a garden in late summer to early fall will extend your gardening season so you can continue to harvest fresh produce after earlier crops are finished.  Planting this time of year also avoids most weeds and insects that have come and gone.

Harvesting fall produce can be extended even further by planting in cold frames and hotbeds.  Hotbeds and cold frames are built the same, their only difference is their source of heat.  The heat for a cold frame is supplied by the sun, whereas the sunlight is supplemented by another heat source in a hotbed.  Building either one of these can be as easy as placing straw bales end to end on the ground and topping them with an old window or two.  Keep in mind that if your cold frame/hot bed is not automatically vented the “lid” will need to be moved on sunny days so that the plants will not become overheated.  Also, the plants in these structures will not be exposed to rain, so check it often for watering needs.

Many spring planted, cool season crops can be planted again in the fall, such as lettuce, spinach, broccoli, cauliflower, peas, cabbage and onions.  Refer to the seed packet for the amount of the average days to harvest.  The average date for the first killing frost in our area is October 6 thru the 15.  Count backwards from the first frost date, using the number of days to maturity for the seed you are growing, to determine the last date you should plant.

When purchasing your spring garden seeds, keep in mind that many garden centers do not carry seedlings for a fall garden planting and you may not be able to find seed packets in the cultivars you want, in the stores when you need them.   Stock up on seeds in the spring as you may need to grow your own transplants for the fall.

Begin by pulling those plants that are finished producing and remove them from the garden.  Work the soil to a depth of 6 to 8 inches.  If your spring garden was heavily fertilized, then you may not need to add any additional fertilizer.   If not, then thoroughly mix with the soil, 1 to 2 pounds of a balanced fertilizer, such as 12-12-12, applied per 100 square feet of garden bed.

As the air temperature will be higher when sowing a fall garden than in the spring, a light application of compost, vermiculite or potting soil over the seeded row can prevent a crust from forming over the seeds and will help keep the soil temperature more suitable for germination.  You can also sow the seeds a bit deeper to take advantage of the cooler soil.  If rainfall is not sufficient, apply 1 inch of water per week, in a single application, to keep the soil moist enough for germination.

Vegetables have differing frost tolerances.  Vegetables that will tolerate a light frost are termed semi-hardy and include beets, carrots, lettuce, endive and cauliflower.   Tender vegetables damaged by a light frost include beans, eggplant, peppers, tomatoes and squash.  Hardy vegetables, or those that can tolerate a hard frost include broccoli, onion, peas, radish, spinach and turnip.

It is recommended to have available a variety of garden blankets, throw cloths and plastic gallon milk jugs to cover and protect plants if a frost should occur.  A few weeks of good growing weather can occur after a cold spell.

As always, Happy Gardening!!

More information about gardening and related subjects is available online at www.hort.purdue.edu/ext/garden_pubs The Purdue University Cooperative Extension Service can be reached at 499-6334 in LaGrange Co., 636-2111 in Noble Co., 925-2562 in DeKalb Co. and 668-1000 in Steuben Co.

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  • Aug 3

by Karen Weiland, Advanced Master Gardener

Composting is a naturally occurring process that breaks down organic material into a substance that resembles soil. Finished compost is an excellent soil amendment that improves soil structure as well as adds some nutrients.

All yards and landscapes produce waste from routine plant care such as pruning and mowing.  Turning that waste into compost is a way to reduce the volume of organic waste in a landfill and return it to the soil to benefit growing plants.  Some communities have an established municipal composting facility to manage large amounts of yard wastes and are quite handy for those who prefer to use that service.

Leaving grass clippings on the lawn is an excellent way to reduce yard waste and if it is mowed at the proper height and frequency will not be harmful to the turf.   The clippings will return some nutrients back to the soil, thus reducing fertilizer needs.  If clippings are too heavy or thick then they should be bagged and used as mulch or mixed into the compost pile.  Clippings from a lawn treated with weed killer should not be used as mulch for at least 8 weeks after the herbicide is applied.  The best method of disposal for these clippings is to just leave them on the lawn.

The site for a compost pile should be in a shady area protected from drying winds and is easily accessible.  To make a compost pile, alternate different types of shredded plant material such as discarded garden plants, grass clippings, tree leaves and pruned material in six to eight inch layers.  The smaller the particle size, the faster the organic materials will break down.  Kitchen wastes such as vegetable and fruit scraps, egg shells and coffee/tea grounds can also be added.  Do not add human or pet feces, meat scraps, bones, fat, plants that are heavily infested with insects and disease  and weeds with seeds.

Use equal parts by volume of dry and green plant materials in the layers with the base layer consisting of coarser, dry materials such as small twigs. A thick layer of grass clippings can mat easily and prevent the movement of water through the mass during the composting process, so mix them in well with other coarser materials.   Adding a little soil or finished compost to the mix will supply all the microbes needed to get started.  Add water to the compost after every few layers of material and apply as needed after the composting process has begun if rainfall is lacking.  Compost with optimum moisture content should resemble that of a squeezed out sponge.

Nitrogen is needed by the microbes to break down and use the carbon found in organic materials.  The ratio of carbon to nitrogen in the compost pile will affect the rate of decomposition. The ideal ratio is approximately 30:1 and can be reached by combining high and low carbon materials such as dry tree leaves and fresh grass clippings.

Oxygen is another element needed for efficient decomposition.  Turning and mixing the pile at least once or twice a month will add needed oxygen and will bring the outer materials to the center for heating and faster decomposition.

Compost can be used as an organic media in potting soil or for starting seeds of garden plants, as a garden mulch to conserve soil moisture and to cover seeds as they are planted to prevent crusting in heavy soils.

As always, Happy Gardening!

More information about gardening and related subjects is available online at www.hort.purdue.edu/ext/garden_pubs The Purdue University Cooperative Extension Service can be reached at 499-6334 in LaGrange Co., 636-2111 in Noble Co., 925-2562 in DeKalb Co. and 668-1000 in Steuben. Co.

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  • Jul 26

by Karen Weiland, Advanced Master Gardener

Say goodbye to dull shady spots and hello to wonderful color, texture and shape.  Not all shade is the same and can be broken down into 5 different categories.

Dense shade means that no light reaches this area.  Full shade will last all day, such as on the north side of a tall building.  A partly shaded area will receive 4 to 5 hours of sun.  A filtered shady spot may seem completely shady but will receive rays of sun through tree branches.  Light shade consists of shade for only 2 to 4 hours between 10 a.m. and 6 p.m.  Figuring out what kind of shade you are dealing with will help you to choose the right plantings.

One of my go-to favorites in the shade garden is the ever popular Hosta, which generally will reach its maturity in 4 to 8 years.  Some varieties are more shade tolerant than others.  There are so many different sizes, colors and textures to choose from.  They are relatively low maintenance but slugs can be a problem.  Diatomaceous earth spread around the plants will keep the slugs away and hand picking them off the plant ensures they will not be chewing more holes in your hosta leaves.  I go out after dark with a headlamp snug on my crown and a disposable cup with soapy water in hand to place the slugs into after picking them off the hosta leaves.  Not a fun job but it works like a charm!

Astilbe is a shade lover that comes with colorful plume shades of red, white and pink.  If planted in sun it will need to be watered consistently.  I know this first-hand as mine dried up to a crispy brown and went dormant during the summer only to sprout again the next spring.

Coral Bells (Heuchera) offer lots of color in not only the flowers but also in the leaves.  Flower colors can range from white, pink and red and the leaves from peach, gold and purple to a variegated white and green.  It is time to divide Coral Bells when the center is dead.  Throw away any woody pieces and transplant.  Every spring I cut off the old foliage and it grows back beautiful as ever.  Hummingbirds are attracted to these flowers.

Pulmonaria is a deer resistant plant that you will find blooming with the daffodils.  It has white to pink speckled leaves and blue, white or pink blooms that are small.  When cutting back the bloom stems be sure to wear gloves so the pricklies will not stay on your hands.

Foamflowers prefer some light shade and different varieties sport shapely and colorful leaves with white to pink blooms in the early spring.  To encourage more blooms cut off the old flowers.

Spring blooming Brunnera, also known as Siberian Bugloss and False Forget Me Not, prefers the conditions of a moist woodland setting.  Dainty blue flowers bloom above the foliage on slender stems that grow to about 18 inches tall.  This plant works very well as a ground cover or in naturalized areas alongside a stream or pond.  Most varieties will take some morning sun but like the afternoon shade.  Check the growers tag when purchasing for sun and moisture requirements.  ‘Variegata” (‘Dawsons White’) will not tolerate sun or drought.

The deer resistant Bergenia sports glossy evergreen leaves and white or pink blooms in the early spring.  It likes part shade, will tolerate full shade (will not bloom as well) and can be grown in full sun (leaf edges may scorch).

There are a number of other plants to choose from for your shade garden.  Check the Purdue University Cooperative Extension website for publication HO-222.

As always, Happy Gardening!

More information about gardening and related subjects is available online at www.hort.purdue.edu/ext/garden_pubs The Purdue University Cooperative Extension Service can be reached at 499-6334 in LaGrange Co., 636-2111 in Noble Co., 925-2562 in DeKalb Co. and 668-1000 in Steuben Co.

Karen Weiland, Master Gardener, Purdue Extension, LaGrange County

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  • Jul 20

by Karen Weiland, Advanced Master Gardener

An infestation of squash bugs (Anasa  tristis)can inflict quite a bit of damage in the garden.  They feed primarily on fruits such as pumpkins, melon and squash and can destroy the plant by sucking its sap from stems and leaves, causing the leaves to wilt and die.  In the fall, they can feed on unripened fruit, causing the fruit to go bad.

Squash bugs are about 5/8 of an inch long, winged and grayish brown with a flat back.  Orange-brown stripes can be seen on the edges of the abdomen and the undersides.  Squash bugs and stink-bugs are sometimes mistaken for each other.  Their shape and size are similar with stink-bugs being wider and rounder and they both release an odor when crushed.  The difference is that stink-bugs have this name because they can release their nasty odor when disturbed, not just crushed.  In the garden, stink-bugs prefer to feed on legumes and tomatoes.

Squash bug eggs are an orange to copper color, 1/16 of an inch long and are laid in clusters on the top or underside of the leaves and on stems.  Nymphs hatch in one to two weeks, are 3/16 to ½ inch long and range in color from a mottled white to a greenish gray with black legs.  They later turn brown, resembling an adult, and start growing their wing pads. During a time period of about 4 to 6 weeks, they molt several times, increasing their size each time and then become adults.

Unmated squash bugs overwinter by finding shelter under garden debris, rocks, wood, etc.  In the spring, they fly from their winter habitat to feed, mate and lay eggs.  Search for them early in the season.  They will be hiding under debris, in perennials and near buildings by the garden.

Place wooden boards or shingles randomly throughout the garden.  Squash bugs will use them as a night time shelter.  In the morning check under them for squash bugs, destroying them when found.

The best method for control of these bugs is through keeping the garden clean.  Remove cucurbit plants after harvest and keep the garden free from debris where bugs can overwinter.  During the growing season, pick off and destroy the egg masses as soon as you discover them.  Use protective covers such as row covers, removing them at bloom time to allow for the pollination process to take place.  Growing vines vertically can make cucurbits less vulnerable to squash bug infestations.  There are some squash varieties that are more resistant to squash bug damage than others.

Using insecticides to kill squash bugs can prove to be difficult because they are often hiding near the crown and can be hard to reach with a spray.  Oils, such as neem oil and horticultural oil, are less toxic to the environment and work the best on the very small nymphs.  Good coverage is essential so that nymphs hiding under the leaves and deep within the plant will be reached.  Diatomaceous earth, a natural pesticide made from the fossilized shells of one-celled organisms called diatoms, is abrasive to many insects and can be dusted over plants to reduce their numbers and will periodically need to be reapplied.  There are other, more toxic, pesticides that can be used however they also have a negative effect on bees and beneficial insects throughout the garden.  If an insecticide is used, it should be sprayed in late afternoon or evening to avoid injury to bees.

As always, Happy Gardening!

More information about gardening and related subjects can be found online at www.purdue.edu/ext/garden_pubs The Purdue University Cooperative Extension Service can be reached at 499-6334 in LaGrange Co., 636-2111 in Noble Co., 925-2562 in DeKalb Co. and 668-1000 in Steuben Co.

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  • Jul 14

by Karen Weiland, Advanced Master Gardener

Talk to any fruit growing gardener about bird damage and you will likely hear a variety of solutions to deter them.  Birds can do so much damage to fruit, especially once it is ripe.  Crows, starlings, grackles and blackbirds, to name just a few, are notoriously destructive to fruit.  Yes, they are just doing what comes natural to them which is looking for a source of food, however there are some steps that a home gardener can take to prevent their feasting on your source of  this winters jams and jellies.

There are a number of steps that can be taken to combat bird damage and most of them fall within three categories: frightening devices, mechanical barriers and habitat modification.

Consider planting serviceberry bushes, rudbeckias, sunflowers and coneflowers, whose seeds and berries birds are very fond of, in an area located away from your fruit planting.   Keep bird feeders filled with black-oil sunflower seeds and keep in mind that birds also feed on insects so they really are useful to have around.

I have found that netting works very well to protect my grapes, however, it must be installed so that it is not merely laying on top of my planting.  Birds are smart and will reach through the netting to eat the fruit.  Instead, support the netting with a system of posts and wires or twine.  Cut the bottom off of a 2 liter plastic bottle and nail it to the top of a wooden post to prevent any tears in your netting.  The netting must be anchored in the ground to prevent birds from entering.  .  The birds will notice the change in the color of the fruit as it is ripening so apply the netting before the fruit ripens.

I’m sure many of you are familiar with the big scare-eye balloons or inflatable owls which are hung on posts every 6 to 20 feet apart.  Birds will get used to them so these generally will work to keep birds away for 10 to 14 days.  Lay out some rubber snakes and change their location every day.  Just remember where you have placed them so you don’t scare the bejeebers out of yourself.  A solar powered great horned owl statue is available whose head turns and bobs every few minutes to mimic the real thing.  I would think that would get a birds attention.

Employing sound devices along with moving devices generally works the best.  Aluminum pie pans can be hung in pairs so that their sound and reflection, when they move, will startle birds and scare them away.

As always, Happy Gardening!

More information about gardening and related subjects can be found online at www.hort.purdue.edu/ext/garden_pubs The Purdue University Cooperative Extension Service can be reached at 499-6334 in LaGrange Co., 636-2111 in Noble Co., 925-2562 in DeKalb Co. and 668-1000 in Steuben Co.

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  • Jul 7

by Karen Weiland, Advanced Master Gardener

I would venture to guess that every gardener, at one point or another, is going to have an infestation of powdery mildew.  It is one of the most widespread and easily identifiable plant fungal diseases out there.  Fortunately, the symptoms of powdery mildew are usually worse than the actual damage and is rarely fatal to a plant.

This fungus is host specific, meaning out of the many different species, each specie only attacks certain plants.   For example, the lilac powdery mildew pathogen cannot infect the honeysuckle plant next to it.

Infected plants will first show signs of infection with small, white, powder-like dots on the leaves.  If not treated, the powdery coating will gradually  spread over a large area of the leaf and stem.  Leaves can become discolored, die and fall off, flowers may become deformed and shoots may be disfigured.  Severely infected vegetable plants may not produce as heavily, have a shortened production time and less taste.  Brownish spots on pea pods can mean an infection of powdery mildew is present.

Previously infected plant material contains cleistothecia (overwintering bodies of the fungus) that will rupture and release fungal spores in the spring.  These spores are carried with the wind to newly emerging, susceptible tissues where they start growing.  Powdery mildew is most prevalent when temperatures are on the cool side and humidity is high or in weather that is very dry.  These pathogens are some of the only fungal organisms that can germinate and infect when there is no free water.

One of the best ways to avoid powdery mildew infections is to purchase plants that are resistant to the disease.  When purchasing, check the plants tag for PM resistance.  In the process of planting, choose a site that is appropriate for the plant, allowing adequate spacing between plants in order to increase air circulation and enough sun to thoroughly dry plant parts.  Some pruning and thinning will help existing plantings by increasing air circulation and light penetration.

If you prune infected plant parts, destroy them, do not place them in the compost pile.  Temperatures are sometimes not hot enough to kill the spores.  In the fall, remove as much of the plant debris in the garden as possible so overwintering spores will not cause infection the following year.

If an application of a fungicide is needed, those with a low environmental impact are suggested.

Horticultural oils, neem oil, wettable sulfur or antitranspirants can prevent infection when applied and can last up to 30 days. Keep in mind that some of these fungicides need to be applied before or at the first sign that the disease is present.   Do not apply these products when the air temperature is above 85 degrees.  Check the label to make sure the plant you will be using it on is listed and follow the instructions for rates to be used, timing of applications and waiting periods before harvest.

As always, Happy Gardening!

More information about gardening and related subjects can be found online at www.purdue.edu/ext/garden_pubs The Purdue University Cooperative Extension Service can be reached at 499-6334 in LaGrange Co., 636-2111 in Noble Co., 925-2562 in DeKalb Co. and 668-1000 in Steuben Co.

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  • Jun 22

by Karen Weiland, Advanced Master Gardener

One of the duties of a Master Gardener is to volunteer to answer questions that are received by the Extension office during the absence of the Extension Educator.  I took on that challenge recently and received quite a few questions to answer.  One of the questions involved an issue with a shade tree.

According to an article written by R. J. Stipes, Professor of Plant Pathology at Virginia Tech and Mary Ann Hanson, Extension Plant Pathologist also at Virginia Tech, anthracnose is a name for a group of diseases caused by several closely related fungi that attack many of our finest shade trees.  It occurs most commonly and severely on sycamore, white oak, elm, dogwood and maple.  Each species of anthracnose fungus attacks only a limited number of tree species.  The fungus that causes sycamore anthracnose, for example, infects only sycamore and not other tree species.  Other anthracnose-causing fungi have similar life cycles, but require slightly different moisture and temperature conditions for infection.

Anthracnose fungi may cause defoliation of most maple, oak, elm, walnut, birch, sycamore and hickory species and, occasionally, of ash and linden trees.  Damage of this type usually occurs after unusually cool, wet weather during bud break.  Single attacks are seldom harmful to the tree, but yearly infections will cause reduced growth and may predispose the tree to other stresses.  Damage may be in the form of:

  • Killing of buds, which stimulates the development of may short twigs or “witches’ brooms”
  • Girdling and killing of small twigs, leaves and branches up to an inch in diameter
  • Repeated early loss of leaves, which over several successive years weakens the tree and predisposes it to borer attack and winter injury
  • Premature leaf drop, which lessens the shade and ornamental value of the tree

Specific symptoms of anthracnose vary somewhat depending on the tree species infected.  That information along with photos can be found by visiting  www.pubs.ext.vt.edu/450/450-604/450-604.html

Anthracnose fungi overwinter in infected leaves on the ground.  Some canker-causing anthracnose fungi, such as the sycamore anthracnose fungus, also overwinter in twigs on the ground or in cankered twigs that remain on the tree.  The spores are blown and splashed to the buds and young leaves and with favorable moisture condition, penetrate and infect the swelling buds and unfolding leaves.  Long rainy periods help the fungus to spread rapidly.

Disease control measures for different trees vary slightly because the period of infection is different depending on the fungal species involved.  If fungicides are used, sprays must be applied on a preventative bases, beginning before infection takes place.  Spraying large trees for many anthracnose diseases may be impractical and unnecessary, especially in dry springs.  Sanitation is important in reducing the amount of fungal inoculums available for new infections.

The article, which is associated with the Virginia Cooperative Extension and Virginia State University, states the following measures should be taken for effective anthracnose control of most anthracnose diseases:

  • Rake up and remove infected leaves in the fall.  Leaves may be shredded and composted or burned.
  • Prune out and burn or bury dead twigs and small branches.  Prune to thin the crown. Thinning will improve air movement and promote faster drying of the leaves.
  • If fertilizer is needed, fertilize in the fall about a month after the average date of the first frost or in early spring about a month before the date of the last frost to increase tree vigor.
  • If chemical control is desired, spray with a fungicide containing mancozeb (e.g. Manzate 200, Dithane M-45) at bud swell and twice again during leaf expansion following label rates.

As always, Happy Gardening!

More information about gardening and related subjects can be found online at www.purdue.edu/ext/garden_pubs The Purdue University Cooperative Extension Service can be reached at 499-6334 in LaGrange Co., 636-2111 in Noble Co., 925-2562 in DeKalb Co. and 668-1000 in Steuben Co.

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  • Jun 8

By Karen Weiland, Master Gardener

The Hollyhock (Alcea rosea) is truly an old fashioned garden plant I like to grow for their tall spikes with showy flowers.  They are the quintessential cottage garden flower and are great for filling in large areas like the back of a flower bed, along a fence or a wall.

Hollyhocks are biennial plants.  They spend the first year of their life building roots and storing energy, growing close to the ground in a circular rosette fashion.  After going dormant for the winter, they re-emerge, growing into a much taller flowering plant that will set seed and then die. Allowing the seed to fall to the ground will ensure more plants for following years.  This plant likes full sun and fertile, well drained soil.  Surround them with a 2 to 3 inch layer of mulch to keep weeds at bay, retain moisture and keep the soil cooler during the hottest days of the summer.

The major disease problem that hollyhocks face is rust, a fungal disease.  It starts as orange, powdery looking spots on the underside of leaves.  Swellings soon emerge within these spots.  As the swellings develop they release masses of reddish-brown spores covering a major portion of the underside of the leaf.   Leaves that are infected eventually turn gray or tan and die.  The reddish spores are easily spread by splashing water, rain and wind. Lower leaves will show the condition first and the disease will progress upward during the growing season.  The extent and severity will depend on weather conditions.  This fungus will overwinter in plant debris and if not disposed of, the symptoms will appear early the next spring in new growth when weather conditions are favorable.

You can help to prevent rust infection by giving the plants plenty of space and ventilation.  Place plants in a sunny, dry location so that moisture can quickly evaporate form the foliage.  Water the soil around the plants rather than the plants themselves as the rust spores will attach easier to wet foliage.  Remove infected leaves as soon as you have identified them and  do not use the infected leaves or plant parts in your compost pile.  Treatment would include use of a fungicide. As in any use of a chemical, read and follow all label directions.  Start spraying in the spring as new growth starts.  You may need to spray several times to protect the young plants.  At the end of the season, remove all infected hollyhock plant material down to the base and destroy it.

When it comes to pests, the hollyhock sawfly is quite common.  The larval form of the hollyhock sawfly is a leaf skeletonizer that eats it way through the leaves, leaving them looking like swiss cheese.  The little green worms are up to ½” long with a black spot on their head and full stomachs.  The plant should be treated as soon as the first holes are seen with Sevin or Bacillus thuringiensis (Bt).  If you decide to forego treatment, the plant will still live, it just will not look very good. Hollyhock weevils are tiny insects that drill into the stem and flower buds for food.  Spider mites, caterpillars and slugs also plague hollyhocks.

As always, Happy Gardening!

More information is available online at www.hort.purdue.edu/ext/garden_pubs.  The Purdue Extension Service can be reached at 499-6334 in LaGrange Co., 636-2111 in Noble Co., 925-2562 in DeKalb Co. and 668-1000 in Steuben Co.

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