In the Grow - Q & A

Q. My mimosa tree has split down the middle of the trunk. Is there any way to save it? Or should I just take it down?

A. Split trunks are a common problem with multi-trunked species such as mimosa. Split trunk is a significant factor for a "risk tree," if it is sited where damage to humans, pets or property could occur when, or if, the tree falls. Cabling and bracing can be completed by a certified arborist to help provide structural support, but the split will still be a weak point in the tree, susceptible to disease, insect pests, decay and further splitting.  <Read More>

September Home, Yard, and Garden Calendar

HOME (Indoor plants and activities)

Prepare storage areas for overwintering tender flower bulbs and garden produce.

Thanksgiving (or Christmas) cactus can be forced into bloom for the Thanksgiving holidays. Provide 15 hours of complete darkness each day, for instance, from 5 p.m. to 8 a.m., for approximately eight weeks. Keep temperature at about 60 to 65F. Temperatures of 55F will cause flower buds to set without dark treatment.

YARD (Lawns, woody ornamentals and fruits)

Fall is usually a good time to plant many container-grown or balled-and-burlapped nursery stock, but if your area is still suffering from drought, it might be best to wait for better conditions. You do not want new plantings to go into winter in drought condition.

If you do have sufficient rainfall or ability to irrigate new plantings, prepare a hole wider than the plant’s rootball, plant at the same depth it grew in the nursery, and water thoroughly. Mulching will help protect against large fluctuations in soil temperature and moisture. Be sure to stake or guy-wire tall plants during their first season to protect them from strong winds.

GARDEN (Vegetables, small fruits and flowers)

Dig up onions and garlic after tops fall over naturally and necks begin to dry.

Plant radishes, green onion sets, lettuce and spinach for fall harvest.

Thin out fall crops such as lettuce and carrots that were planted earlier.  <Read More>

Stressed Plants May Look Like Early Fall

To state the obvious, many of our landscape plants really show the signs of excessive heat and extreme drought. Some trees are losing leaves already and may be turning color before they drop. Others have turned completely brown while still remaining attached.

Early fall color and/or defoliation is common when plants are under stress and this season has been quite challenging for many trees, both old and young. The intense heat made it difficult for plants to keep up with water and cooling requirements, even in areas where moisture was adequate. Combine extreme heat with drought, and it is a wonder any plants survive.  <Read More>

Upcoming Events - Purdue Master Gardener Course to be Offered this Fall

If you enjoy gardening and enjoy “Helping Others Grow”, make plans to take part in this fall’s Purdue Master Gardener Course in Spencer County.   

The Purdue Master Gardener Program is a volunteer training program which offers an extensive course in horticulture in exchange for a donation of volunteer hours to help teach others what you have learned. 

The course will be held on twelve consecutive Monday evenings from 6:00-9:00 PM, beginning September 10, at the Spencer County Youth and Community Center in Chrisney, IN. 

Participants will be exposed to a wide range of subjects including soil and plant science, diagnosis of plant problems, pesticide safety, composting, and culture of vegetable, flower, landscape, and fruit plants.   

A $125 per person supply fee will be charged to cover such items as reference materials, mailings, name badges, and refreshments. Couples or two family members who wish to take the course together and share reference materials can register for $200 per couple. Registration deadline is August 31.    

If you'd like an application to join our new team of volunteers or have questions about the program, please contact Nicholas Held at the Spencer County-Purdue Extension Office at (812) 649-6022 or nheld@purdue.edu.  Applications are also available online.

August Home, Yard, and Garden Calendar

HOME (Indoor plants and activities)

Take cuttings from plants such as impatiens, coleus, geraniums and wax begonias to overwinter indoors. Root the cuttings in media such as moist vermiculite, perlite, peat moss or potting soil, rather than water.

Order spring-flowering bulbs for fall planting.

YARD (Lawns, woody ornamentals and fruits)

Newly established plants are particularly vulnerable to extreme heat and drought. If possible, apply 1 to 1.5 inches of water every 7 to 10 days as a gentle, thorough soaking.

Even well-established trees, shrubs and perennials will suffer from extreme heat coupled with drought. Symptoms may include wilting, leaf scorch, branch dieback, blossom drop, early "fall" color and leaf drop, and in some cases, plant death of specimens that were already ailing.

GARDEN (Vegetables, small fruits and flowers)

Temperatures above 90 F often leads to poor fruit set in most vegetable crops; upper 90s will stop fruit set in nearly all crops. Fruits that were already set may show uneven ripening, blossom-end rot, skin cracking, sunburn where foliage cover is poor, poor ear fill in corn and bitter flavor in cucumbers and other vegetables.

Keep the garden well watered during dry weather and free of weeds, insects and disease. Early morning is the best time to water, but areas under watering restrictions may need to adjust accordingly. While normally we discourage overhead sprinkling due to its inefficiency and potential for promoting plant disease, it can be very effective at decreasing temperature in the plant tissue.  <Read More> 

In Times of Drought

Dry summers are not that unusual in the Midwest, but this year's dry spell - and now drought in many areas - has come considerably earlier than usual. Summer is just now officially getting started!

Gardeners have a battle on their hands to keep plants healthy when extremely high temperatures are accompanied by lack of rain. During prolonged drought conditions, water restrictions or just limited ability to water to a huge number of plants, you may have to limit watering and prioritize which plants will be rescued - a bit of garden triage, so to speak.  <Read More>

In Times of Drought - Video

This video is a companion piece to the above article and features Rosie Lerner, Purdue Extension Consumer Horticulture Specialist, covering some basics of helping your vegetable and landscape cope with the drought. 

Drought....and the Potential for More Drought

US Drought Monitor report for Indiana.  For more information, see the Drought Monitor website.

This week's US Drought Monitor Report indicates an increasing area of Indiana is now under a moderate or severe drought, with a portion of southwest Indiana falling under the "severe" category.  While certain aspects of the current drought conditions have some producers and others thinking "1988" in the back of their minds, it is too early to make such a prediction.

So far, Spencer County has fared better than our neighbors to the west and northwest.  Though we are in the moderate drought category, infrequent but timely rainfall, combined with cooler temperatures, especially overnight, have kept drought effects in crops, gardens, and home landscapes from becoming widespread.   

There is a slight chance of scattered showers this weekend but according to staff at the Indiana State Climate Office, the next chance for more widespread, substantial rainfall is not until late next week.  As a result, we are in a bit of a wait-and-see pattern as far as how the drought will progress, with the next 10-14 days being crucial.  If one or both of these predicted systems produce rainfall,  it could be just the timely rain event we need to hold off further drought progression, at least for a few more weeks.  However, if these systems fail to bring moisture, we could then be at the tipping point for something much more severe. 

As we watch how the situation progresses over the next two weeks, we will continue to post drought management information on the Gazette, on our Facebook page, and in our bi-monthly newsletter.  In the meantime, below are two articles addressing the topic.  The first is a recent article covering the effects we are currently seeing in corn and soybean crops.  The second, originally written in 2007, covers tips for home gardens and landscapes.

More Crops Affected as Drought Spreads Throughout Indiana

Help Your Garden Cope with Dry Spell

In the Grow - Q & A

Q. I have been trying, without success, to eliminate the wild violets from my yard. I have tried many different broad leaf weed sprays with no luck. They seem to be invincible! What can I use that is effective?

A. My yard also has a great population of both white- and blue-flowering violets, but I like them! I welcome their presence and look forward to seeing their lovely blossoms each spring. But I realize I may be in the minority on that.  <Read More>

Sap-sucking Bugs Make a Mess of Indiana's State Tree

Tuliptree with scale and
sooty mold (Purdue PPDL)

Across Indiana this week, homeowners with tulip poplar trees could be finding their cars and landscape plants covered in a mysterious sticky film. This time of year tulip poplars are easily recognized by leaves whose shape resembles a tulip and the two inch long lime green and orange flowers in the tree canopy.

The culprit in this sticky mess could be the tulip tree scale insect, a small sap-sucking bug that feeds on the trees’ branches. Declared as the state tree of Indiana in 1931, tulip poplars are well-regarded and widely planted for their beautiful flowers and form, shade, and rapid growth. The tree’s sap carries vital nutrients, and feeding by the insect can cause damage to the trees in addition to the unsightly mess.  <Read More>

June Home, Yard, and Garden Calendar

HOME (Indoor plants and activities)

Indoor plants will require more frequent watering and fertilization as they increase their summer growth.

Houseplants can be moved outdoors to a shady location, but pay close attention to their watering needs.

YARD (Lawns, woody ornamentals and fruits)

Prune spring-flowering shrubs after blooms fade.

Apply fungicide to prevent and control black spot on roses.


GARDEN (Vegetables, small fruits and flowers)

Discontinue harvest of asparagus and rhubarb around mid-June to allow foliage to develop and store food reserves for next year’s harvest. Fertilize and water when dry to promote healthy growth.

Mulch to control weeds and conserve soil moisture after soil has warmed. Many materials such as straw, chopped corncobs, bark chips, shredded paper and grass clippings can be used.  <Read More>

In The Grow - Q & A

Q. What is the best way to eradicate henbit? Would a weed-and-feed in fall or spring be most effective? Would a spray weed killer be most effective in spring or fall? Could you use a pre-emergence like crabgrass preventer in the fall?

A. Henbit is a winter annual, meaning it germinates from seed in the fall, overwinters in a dormant state and then blooms and sets seed to complete its lifecycle in late winter/early spring. By mid- to late spring, the foliage will turn yellow, but if allowed to remain until then, it will have produced a lot of seed to germinate in years to come.  <Read More> 

May Home, Yard, and Garden Calendar

HOME (Indoor plants and activities)

Many indoor plants can be moved to shady locations outdoors but only after danger of frost is past. Plants will dry out more often outdoors, so keep a close eye on soil moisture. Sinking the pots in soil will help slow down moisture loss.

YARD (Lawns, woody ornamentals and fruits)

Prune early spring-flowering trees and shrubs after flowers fade.

Plant balled-and-burlapped or container nursery stock, and water thoroughly.

GARDEN (Vegetables, small fruits and flowers)

Plant frost-tender plants after danger of frost is past for your area. This includes warm-season vegetables, such as tomatoes, peppers, eggplant and vine crops, as well as most annual flowers and tender perennials, such as cannas, gladiolus, dahlias, tuberous begonias and caladiums.

Pinch chrysanthemums and annual flower plants to keep them compact and well branched. <Read More>

Assessing Freeze Damage on Fruit

Commercial and home fruit growers across the state have been assessing potential damage to their crops after last week's overnight freezing temperatures.  While a freeze/frost event this time of year is certainly not unusual, what was unusual is how far ahead of schedule fruit crops are this year compared to normal. 

To help growers better assess damage to common tree and small fruits, Purdue Extension Specialists Bruce Bordelon, Peter Hirst, and Jon Obermeyer have produced a series of videos addressing last week's freeze and the effects on apples, peaches, grapes, strawberries, and blackberries. 

The videos are available on the Purdue Extension Entomology YouTube channel.  Links to each specific video are below:

Assessing Spring Freeze Damage to Apples
Assessing Spring Freeze Damage to Peaches
Assessing Spring Freeze Damage to Grapes
Assessing Spring Freeze Damage to Strawberries
Assessing Spring Freeze Damage to Blackberries

What's Growing in my Pond??!! - Part 2

In a previous post, I described various preventive measures for aquatic vegetation control. While these measures will help prevent weed growth, they are not the answer for eliminating weed infestations that are already present. If this is the case, there are various mechanical, biological, and chemical methods available to control aquatic weeds.

Mechanical control involves physically removing the plants. This can be done by hand or with special hand-held devices designed for cutting and pulling pond vegetation, available from aquatic/fisheries suppliers. Most aquatic plants are perennial and will re-sprout if the plant is not entirely removed, including growth below the ground. For larger bodies of water, motor-driven underwater vegetation harvesters are available. This equipment is a major investment and is not a feasible option for most individuals on privately owned lakes and ponds.

In severe cases of emergent plant growth, such as cattails, complete removal with a backhoe or other equipment may be necessary. 

Biological control refers to the use of organisms to control vegetation. Biological control of aquatic vegetation has received considerable publicity recently and research is currently being conducted to determine the ability of bacteria, fungi, and insects to control aquatic plant infestations. The research has shown some potential but it is too early to tell if this type of control will work on a widespread scale.

The most widely used biological control is grass carp. Grass carp consume some algae and most submersed plants but have the potential to completely remove all underwater vegetation in a body of water. Grass carp can provide good control of pond vegetation but they have a tendency to feed on beneficial native plants before the truly troublesome weeds, such as Eurasian watermilfoil or mat-forming algae. Also, their feeding rate slows after about five years, so more fish may need to be added. Grass carp are not effective controls for duckweed or watermeal.

Private landowners in Indiana do not need a permit to introduce grass carp into their ponds but there are restrictions. First, the fish must be purchased from a holder of an aquaculture permit and the permit holder must deliver and stock the fish. Next, the land surrounding the pond or lake must be totally in private ownership. Finally, precautions must be taken to ensure the fish do not escape the stocked area, such as erecting barriers at the spillways and outflows.   

Chemical control is the most common method of aquatic plant control. A variety of chemicals are available to control different types of vegetation. When used properly, chemical controls are safe and effective. However, many are only temporary solutions and require repeated applications to prevent the vegetation from returning. When using chemical controls, read and follow all label directions. The type of chemical required depends on the type of vegetation you want to control. Many chemicals also have waiting periods on the use of water treated with the herbicides. These mostly have to do with fishing, domestic use, livestock watering, and irrigation.  

The best time to apply aquatic herbicides is late spring. Do not wait until July or August. Late summer treatments can kill fish. By that time of year, vegetation is extensive and thick and the water is warm. Killing off vegetation under these conditions seriously depletes oxygen levels in the water and can result in fish kills. If you must treat in late summer, treat only a portion of the vegetation at a time.

Additional information on aquatic weed control, including specific herbicide recommendations, can be found in Purdue Extension Publication APM-3, Identifying and Managing Aquatic Vegetation.

What's Growing in my Pond??!! - Part 1

Blue-green algae bloom (Held)

In mid- to late-spring each year, I receive a few calls on controlling pond vegetation.  However, this year these calls have been coming in about a month early (just like everything else) and with seemingly greater frequency than recent years.  Just as grass and weeds in the lawn have been thriving this spring, so has pond vegetation.  And from what I have seen so far, "thriving" is an understatement. 

Blue-green algae bloom, closeup (Held)

Proper management of pond vegetation is crucial, especially in years like this when unimpeded early, rapid growth could spell trouble for pond ecosystems later this summer.  This post will deal specifically with preventive control methods, the first step in controlling pond vegetation.  In a later post, mechanical, biological, and chemical controls will be covered.     


American pondweed (APM-3)

While it may be tempting to achieve a sterile, swimming pool effect in a pond, this is not a desirable outcome. The goal of a good aquatic plant management plan is to achieve a balance between too much vegetation and too little vegetation. Some plants, particularly native species, are highly desirable and add interest and appeal to the pond. But how is this balance achieved? The best way to achieve balance is the careful use of one or more management methods, including preventive, mechanical, biological, habitat alteration, and chemical methods.

Many pond weeds or their seeds are carried into a body of water by wind, birds, fish introduction, boat trailers, fishing, etc. Prevention starts with reducing or eliminating the causes of the spread; i.e. discouraging geese from visiting your pond, washing plant fragments off boat trailers and boats before moving to a new site, and removing plant fragments when moving fish or fish bait from one site to another.

A newly introduced weed will become a problem only if water conditions are just right. Good growing conditions usually mean the body of water is shallow or has shallow areas with good light penetration, and has an available source of nutrients (nitrogen and phosphorous) either in the water or stored in the sediment. Often nutrients enter a pond from runoff or stream flow. In addition to monitoring and reducing or eliminating nutrient and sediment sources in the watershed, the following steps can be taken to help prevent weed growth.

First, do not fertilize the pond or lake. In the Midwest, most waters are sufficiently rich in food organisms to feed large fish without being fertilized. Next, maintain a good sod and grass cover around the pond or areas that drain into the water. This will help absorb nutrients that might flow into the water as well as help control erosion. It is also thought that taller vegetation around a pond reduces the chances of Canadian geese colonizing a water site. A third step is to not apply fertilizer within 20 feet of the bank.

Livestock should not be given access to the pond except in cases of extreme heat stress. If the pond is used for livestock water, it should be fenced and the animals should be used watered using a stock tank outside the pond. Animals can add turbidity and fertility to the water and tear down the banks. It is also important to make sure run-off from feedlots or other livestock pens does not run into the pond.

Finally, a settling or retention pond or wetland area can be established to receive and settle out nutrients before the flow reaches the main body of water.

Stay tuned for Part 2.........

In the Grow - Q & A

Q. My rhubarb plant has been blooming and I have been cutting them off, but recently heard that rhubarb leaves are poisonous. Are the flowers poisonous, too? Do I need to wear gloves? What causes them to bloom?

A. The flowers (and the leafy foliage) of rhubarb plant are toxic if ingested, but not generally considered a skin toxin. However, some do find the sap an irritant, so it's always a good idea to wear gloves when gardening.

It does appear that some rhubarb plants are more prone to flowering than others. Old-fashioned varieties, such as Victoria and MacDonald, are heavy seed-stalk producers. Canada Red and Valentine are less likely to bolt. Plant maturity is also a factor, with more mature plants being more likely to bolt than youngsters. Dividing the crowns every 4-5 years should help rejuvenate the planting. And, no doubt, weather also plays a role, as it does seem to be more problematic in some years.  <Read More>

Growing Fruits and Vegetables in Containers

If you lack adequate space for a full-fledged garden but still would still like to enjoy a few fresh fruits and vegetables this summer, container gardening may be the answer for you. Flowers are not the only plants that do well in containers. In fact, most fruits and vegetables have varieties which will do well in containers. Strawberries are the most common container fruit while tomatoes are the most common container vegetable. Lettuce, green onions, radishes, cucumbers, and peas are also popular choices.

An increasing number of varieties are developed each year that are adapted for limited space areas; everything from grafted dwarf fruit trees to bush-type cucumbers. In seed catalog descriptions, many companies specify use in containers for small-size fruits and vegetables.

Just about any container can be used to grow fruits and vegetables; from whiskey barrels and bushel baskets to clay pots and hanging baskets. The key to success is to make sure the container provides adequate drainage. Water should not be allowed to stand in the bottom of the container. To provide proper drainage, the container should have holes in the bottom to allow the water to run out. The type of soil used can also have an effect on drainage. Garden soil alone should not be used in containers because it will soon become compacted and water will not drain through it properly. Sterilized compost mixed with peat moss and vermiculite works well, as does potting soil mix. You can even use the potting soil bag as the container. Lay the bag flat and slit holes in the bottom for drainage, then turn the bag over and cut openings in the top for the plants. This technique is known as “bag-culture” or “pillow packs”.

The containers should be placed in full sun and should be protected from strong winds. A water source should be close by or the containers should be easy to move so they can be watered regularly, especially during dry spells. You may also need to use portable containers if they are to be used as porch or patio decorations or if they need to be moved to a protected area during the winter. If you have a fruit tree growing in a container, be sure to move it to a protected location in the winter. If left out, the roots will freeze and the tree will die.

Fruits and vegetables grown in containers are still susceptible to the same insects, weeds, and diseases as those grown in garden beds, so it is important to take proper measures to control them. Using a sterilized soil mixture can help avoid soil borne insects and diseases. Removing dead leaves, flowers, and over-ripe fruit will also help control these pests. Inspect the plants regularly for insects and pick them off as you notice them. If the infestation becomes large, it may be necessary to use a pesticide to control them, making sure the chemical is labeled for use on all the plants in the container.  

Weeds are not as much of a problem in container gardens but they can quickly take over if not properly controlled. The best way to control weeds in the container is to make sure the soil in the container does not have weed seeds in it. Potting soil or peat moss generally will not have weed problems but if your soil mixture contains compost or garden soil, these materials should be taken from areas that are not weed infested. If you do find weeds growing in your containers, carefully pull them while they are small. Larger weeds should be cut out so as not to damage the surrounding desirable plants. Herbicide use is not practical for container gardens.

Additional information on container gardening can be found in Purdue Extension publication HO-200, available here.

April Yard and Garden Calendar

HOME (Indoor plants and activities)

Start seeds of warm-season plants, including tomatoes, peppers, eggplant, marigolds, zinnias and petunias, indoors for transplanting later to the garden.

Harden off transplants started earlier in spring before planting outdoors - gradually expose the young plants to outdoor conditions of wind, brighter sunlight and lower moisture.

YARD (Lawns, woody ornamentals and fruits)

Plant a tree in celebration of National Arbor Day, April 27. Bare-root stock should be planted before new top growth begins. Balled- and-burlapped and containerized stock can still be planted later in spring.

Fertilize woody plants before new growth begins. Two pounds of actual nitrogen per 1,000 square feet should be sufficient.

GARDEN (Flowers, vegetables and small fruits)

Plant seeds of cool-season crops directly in the garden, as soon as soil dries enough to be worked. When squeezed, soil should crumble instead of forming a ball. Cool-season crops that can be direct-seeded include peas, lettuce, spinach, carrots, beets, turnips, parsnips and Swiss chard.

Plant transplants of cool-season crops, such as broccoli, cauliflower, cabbage, Brussels sprouts, kohlrabi and onions.  <Read More>

Weird Weather and Pest Predictions

One of the most common questions that has come up in response to this season's winter weather (or lack thereof) is what effect it will have on pest problems this spring or summer, particularly insect populations.  Below are excerpts of responses given by two Extension experts. 

Larry Caplan, Extension Horticulture Educator in Vanderburgh County addressed this question in a recent newspaper column:

I was asked the other day what effect this strange weather will have on our pest problems this year. That is always a very tough topic for me. I don’t like to make predictions, because there are so many variables that can affect future events, rendering my predictions worthless. Still, there are a few things that I expect will happen this season.

First of all, everything will start happening at least 3 weeks earlier than normal because of the long warm-up we’ve had. Crabgrass germination occurs at about the same time as the forsythia shrub blooms. Usually, we can hold off applying our pre-emergent herbicides until mid to late March; this year, though, some parts of the tri-state may already be too late to get the best preventative control.

Dormant oil is applied to fruit trees to prevent later problems with spider mites. The oil needs to be applied before the trees bud out, otherwise the young leaves will be burned by the chemical. It’s already too late in some places. Likewise, the traditional orchard sprays to control disease and insect attacks should begin as the buds open. Normally, gardeners don’t expect to begin this until late March or early April, but I’ve already seen apple and cherry trees in bloom. Be sure to stop spraying while the flowers are open, so that you don’t hurt any bees that may be out.

The repeated storms of the last few weeks have dumped a lot of moisture on the tri-state. With moist conditions and standing water, we can expect increases in biting midges, mosquitoes, and crane flies. This is what we’ve seen for the last couple of years, which have all been pretty wet.

Warm, moist weather is ideal for fire blight, a bacterial disease that attacks apples, crabapples, and pears. The bacteria usually enters the tree through the flowers, but it can also enter twigs damaged by hail storms. Spraying the antibiotic Streptomycin during bloom and after a hail storm may offer some protection.

If warm weather continues, we may see an earlier emergence of Japanese beetles, eastern tent caterpillars, and other pests, but I don’t believe we’ll see increased numbers. Very few of these insects are killed by severe winters, so I don’t think their survival rate will change much.

And from Dr. Rick Foster, Purdue Extension Entomology Specialist, some points focusing specifically on insect populations:

While some insects, such as flea beetles, are directly impacted by cold winter weather and experience greater survival and higher populations as a result of mild winters such as the one we just experienced, many insect species are very well adapted to winter weather and will survive just fine no matter how cold it is.

Most insects have an amazing ability to reproduce in large numbers and, if spring and summer weather is conducive, will be able to develop to serious population levels no matter how many survived the winter.

Finally, some of our pests overwinter indoors and others overwinter in the South, so our winter weather has little effect on their populations.

The bottom line is that for a few insects, we can definitely expect higher populations, but for many others, we just can’t predict.

As you can see, there is no one answer to this seemingly simple question.  While winter weather conditions have little effect on most insect populations, it is the earlier-than-normal emergence of these insects, as well as weeds and diseases, that will be the most likely effect of our mild winter.  And, as Mr. Caplan adds, this is Indiana, so it could snow this weekend and change everything!