Northwest Illinois Horticulture Corner In the far Northwest Corner of Illinois, gardening is a very popular pastime! Get your info here! Sun, 15 May 2005 13:02:08 -0500 Why succulents are ideal plants Thu, 02 Aug 2018 12:04:00 +0000 This blog post is written by Extension Educator Candice Hart,

Succulents have long been a favorite group of plants for gardeners, for one great reason: They don't need to be watered often! For a gardener who feels watering is a chore, succulents are a dream.

By definition, a succulent is a plant that has thick fleshy leaves or stems adapted to storing water. Therefore, succulent is a very broad term that can include many, many plants. Some of the common succulent plants you may be familiar with are hens and chicks, jade plants, aloe plants, or holiday cacti, just to name a few.

"First of all, succulents need minimal watering. For a gardener that works or travels a lot, succulents are a great choice. They thrive on neglect and dry soil. In fact, the easiest way to kill a succulent plant is by watering too much," says Candice Hart, a horticulture educator with University of Illinois Extension.

Hart points out a few more benefits of growing succulents. For example, she says they rarely suffer from diseases and pests. Besides the occasional mealybug, there are usually very few problems that pop up on succulents. "Succulents also have really interesting flowers and plant forms. The variety of colors, shapes, and patterns that are available in succulent plants is like nothing else."

Even though succulents are fairly low-maintenance plants, Hart says there are a few tips and tricks that can keep them healthy and happy.


If growing succulents indoors, a southern- or western-facing window would have the most ideal lighting for these sun-loving plants. Many succulents will thrive under incandescent or fluorescent supplemental lighting if the ideal lighting situation is not available.

Succulent container gardens can be taken outdoors for the summer and kept as houseplants for the winter. "Fill a sunny deck with succulent container pots for the summer and then, before the temperatures dip below freezing, bring those pots in and keep them as houseplants for the winter," Hart says.


Most cacti and succulent plants can adapt to wide fluctuations of temperature because that is what occurs in their native desert habitats. It is naturally very warm in the day and cold at night in the desert.

Exposure to temperatures between 40 and 90 degrees Fahrenheit for long periods is not harmful to succulent plants. In fact, many desert plants will initiate flower buds when grown in a cool, dry, well-lit location. Nighttime temperatures of 45 to 50 degrees are suitable to stimulate flower bud formation.


The amount of water needed for a container garden really depends on the time of year, the size of the plant, the type of potting soil, and the size of the pot. As a result, these plants can't be watered on a set schedule because of those varying factors. "In other words, you can't set an alarm to water your succulent containers every Monday," Hart says. "Watering without taking the conditions into account can easily lead to overwatering the container."

Overwatering is by far the easiest way to kill a succulent or cacti plant, so prior to watering, check the soil with your finger to judge the amount of moisture still left. If the soil still feels moist, don't water yet. Wait until the soil completely dries out before watering again.

If these basic care instructions are followed, you'll be a succulent-growing pro!


Reduce Your Plastic Footprint Mon, 30 Jul 2018 11:58:00 +0000 This blog is written by Extension Educator Jennifer Fishburn, 217-782-4617,

Reduce, reuse, and recycle. The three R's are part of being a good steward to the Earth. Jennifer Fishburn, a University of Illinois Extension educator, points out that it is ironic that the horticulture industry, whose goal is to beautify our yards, uses millions of plastic pots and trays each year.

Plastics are a rapidly growing segment of municipal solid waste, she says, and one of the largest categories of plastics includes pots and flat trays that hold plants. In a 2004 estimate, Penn State University's College of Agriculture Sciences estimated that cell packs, flats, and assorted nursery pots account for more than 320 million pounds of plastic produced each year.

Ultimately, Fishburn says, the solution is for the industry to go "green" and offer plants in biodegradable pots. The makeup of commercially available biodegradable pots vary. They can be made of wood fiber, paper, peat moss, or animal products such as cow manure. Drawbacks of biodegradable pots are that some tend to be more fragile or expensive than plastic containers.

"But the benefits of using biodegradable pots are that they won't end up in the landfill, plants experience less transplant shock, and roots stay intact."

A study on biodegradable pot strength and biodegradability was undertaken by Longwood Gardens, Louisiana State University, and the University of Arkansas. Researchers tested plantable pots: peat, CowPots®, fertilepot, cocofiber, StrawPot; and compostable pots: ricehull, paper and cord fiber, OP47 bio pots. Cowpot® containers decomposed the most readily, and cocofiber the least. Complete results of the study can be found at

"Until the horticulture industry begins using biodegradable pots, it is our job as gardeners to reduce, reuse, or recycle plastic containers and not send them to the landfill," Fishburn says.

She offers a few tips for gardeners:

  • Reduce the number of containers by starting seeds at home. Consider starting seeds in homemade newspaper pots.
  • Reuse plastic pots for planting next year's seeds or donating divisions to a local plant sale. If reusing containers, be sure to disinfect plastic pots by soaking clean pots in a solution of one part bleach to nine parts water for ten minutes.
  • Recycle plastic pots and trays. Many recycling programs do not recycle plastic pots made of numbers 2, 5, and 6 plastics. Check with your local garden center or hardware store to see if they have a plastic pot recycling program. For example, all Lowe's garden centers will recycle plant pots and trays. Simply return clean pots and trays to the store nearest you. According to Lowes' website, reusable material is sterilized and reintroduced to the production cycle, while non-reusable material is sent for recycling.


The mystery lurking under the pond turns radiant Tue, 10 Jul 2018 12:05:00 +0000 This blog post is written by Extension Educator Kelly Allsup,

They are the stuff of nightmares, but can make us stand in awe at their beauty. Their dark, extended bodies are poised to attack while lurking under water. They propel themselves through the water with a forceful expulsion of water through their rectum, directing themselves at any unsuspecting insect, small fish, or tadpole. They snatch at their prey with an enlarged lower jaw that looks like it may detach due to the vigor of the attack. Some crawl with long legs while on the hunt and some wait in ambush. When they are fully-grown nymphs, they surface from the water and an adult emerges from the splitting exoskeleton.

If you have not guessed by now, this mystery creature is a dragonfly.

"Dragonflies have been on Earth since before the dinosaurs, and they continue to captivate us today. As adults, their hefty size, vibrant color patterns and spectacular aerial agilities make them a standout in the garden," says Kelly Allsup, University of Illinois Extension educator.

Adult dragonflies are different from their cousins, the damselflies, in that they hold their intricate wings horizontal to their body when perched. Damselflies close their wings when they are perched and have much more slender bodies than the dragonfly. Dragonflies have very large compound eyes that bulge on the sides of their head, allowing for a 360-degree field of vision. Each eye can contain 10,000 to 30,000 individual facets or light-sensing units, allowing for excellent vision.

They will eat flies, mosquitoes, wasps, butterflies, and even other dragonflies, often in dramatic fashion.

"Dragonfly adults, however gorgeous, scoop their prey up with their legs during flight and swiftly tear it to pieces with their massive jaws and razor sharp mandibles, making them the top of the insect food chain," Allsup says. "However, all of this happens too fast for us to see. When flying, they can top out at 30 mph, making it very hard for a 4-Her to catch one for their fair project without the swift and steady sweep of a net."

Any onlooker who visits a pond or lake in the summer has most likely seen the mating ritual of the dragonfly. The sexually mature males are territorial, as water is crucial to complete their life cycle. They make trips to scout for other invading males and mates.

"When a mate is found, the male clutches the females head and she brings her abdomen up to a special structure that holds the sperm. This is known as the wheel position. In some cases, males have adapted special techniques to remove the sperm of a previous mate," Allsup says.

Once they have mated, the females will dart around a body of water looking for a suitable site with submerged vegetation to lay her eggs. All the while, the male will either hover above her or remain clasped to her to prevent other males from mating with her.

Dragonflies are excellent beneficial insects in the garden but require ponds, plant variety, hiding and perching spots in rocks, shrubs and trees, and full sun.


To Spray or Not To Spray in the Garden Sat, 07 Jul 2018 11:54:00 +0000 This blog post is written by Extension Educator Martha A. Smith,

Stop and think before grabbing a bottle of pesticide to control garden pests. That's the message University of Illinois Extension educator Martha Smith wants to convey to gardeners this season.

"Integrated Pest Management stresses monitoring your landscape, keeping a keen eye out for problems from the start," Smith says. "Ask yourself, should I spray or is there an alternative? Most pest problems start out small.

"Perhaps an infested branch can be removed. Simply hand-picking the critters off a plant can save you time, energy, money, and chemicals. How much pest damage are you willing to tolerate? If you seldom stroll through your landscape you might not see that pest until it has consumed a major portion of your investment. At this time, a pesticide control may be the only choice."

We are in the midst of gardening season. Pests are sure to attack. Monitoring and considering control options are signs of a responsible gardener, according to Smith. "Remember, a pesticide is any product used to control a pest, and a pest is anything harming your plant. Fungi, insects, bacteria, or rabbits could all be considered pests," she says.

Both synthetic and organic products are available for controlling garden pests. Regardless of what type of control you select, Smith offers a few tips to effectively apply the product.

  1. Read the label. Understand what the product is intended to do and when during the lifespan of the pest it should be applied. Correct timing will give the best control with the least amount of chemical.
  2. Correctly identify the pest. Caterpillars resemble sawfly larvae but the products to control them can be different. Also, is that caterpillar a true pest? If you choose a caterpillar control, don't question the absence of butterflies later in the season. Caterpillars can be voracious eaters, but the majority will turn into colorful butterflies. Consider the "pest factor" before spraying.
  3. Mix material as directed. Don't think if one teaspoon is recommended, two teaspoons will be better. Effectiveness will not increase by doubling the amount of chemical. In fact, higher concentrations can harm plants.
  4. Follow all personal safety instructions on the label. A sleeveless tank top and flip-flop sandals are probably not the recommended protective clothing. Consider a long-sleeved shirt, pants, eye protection, socks, closed-toe shoes, and gloves if not already instructed on the label.
  5. Use measuring utensils – don't guess at amounts. Have a set of measuring utensils specifically designated for chemicals. Write on them "chemicals only." Don't use utensils that are also used in food preparation.
  6. Spray on the target. Don't apply a chemical across a 20-foot border when only 2-3 square feet require attention - it may not be necessary. Read the label to find out if the entire plant needs to be sprayed. Spray to the point of runoff and stop.
  7. Pollinators can be harmed with certain pesticides. Consider spraying after the plant has finished blooming and pollinators no longer visit. If you must spray while the plant is in bloom, spray when insects are not active, such as dawn and dusk.
  8. Application equipment should be in good working order. Leaks can lead to damage on non-target plants. Use equipment that is recommended on the label.
  9. Spray when the weather is calm. Pesticide drift occurs when spray is carried off-target by the wind. Drift can also be minimized by spraying at a lower pressure and using the largest nozzle opening that will still allow you to complete the task.
  10. Watch the weather and avoid the heat of the day. Some pesticides will burn plant material if applied when temperatures are too hot. High temperatures can also cause some pesticides to evaporate and decompose quickly. Spray in the morning.
  11. Watch the weather and avoid spraying before rain or before overhead irrigation. This will reduce effectiveness by washing the material off the target plant, possibly leading to groundwater contamination.

Keep these spray guidelines in mind when selecting a pest control for your landscape. Monitor and identify the pest early. Consider your control options. Remember your control selection may not be what your neighbor would choose. Be a responsible gardener and ask: "To spray or not to spray?"


Common Garden Tomato Problems Mon, 25 Jun 2018 11:48:00 +0000 This blog post is written by Extension Educator Martha A. Smith,

Now that summer has arrived, gardeners are noticing problems with their tomatoes. There are a number of diseases affecting Illinois-grown tomatoes, says University of Illinois Extension educator Martha Smith, but the most common are early blight, Septoria leaf spot, and late blight.

Early blight, also known as Alternaria leaf spot, can affect plants at any stage of development. All above-ground parts are susceptible.

"The most characteristic symptom of early blight are spreading spots, a quarter to a half inch in diameter that form on lower or older leaves," Smith says. "These spots have dark edges and they are usually brown to black in the center. They frequently merge, forming irregular blotches. Concentric rings often form creating a 'target' or 'bulls-eye' effect."

Affected leaves develop yellow areas around the lesions. Eventually leaves become entirely yellow, then wither and drop off. The fungus may cause lesions on the fruit around the stem end and shoulder. The lesion is usually dark brown to black, up to an inch in diameter, with distinct concentric rings.

Septoria leaf spot can also affect plants at any stage of development. Numerous small, water-soaked spots first appear on the lower leaves. These spots soon become circular to angular with dark margins and grayish centers often having one or more tiny black bodies called pycnidia, which are spore-bearing structures.

"Individual lesions are seldom more than an eighth inch in diameter and are usually quite numerous on an infected leaf," Smith says. "Heavily diseased leaves turn yellow, wither and drop off in large numbers, starting at the base of the plant. Defoliation can be severe during prolonged periods of warm, wet weather."

Late blight in garden tomatoes usually appears in mid- or late August.

"A primary source of this disease can be from leftover potatoes from last year's garden. The fungus that causes late blight needs living tissue to survive over the winter, so it can't overwinter on tomato cages or supports. However, infected potatoes (the other plant that gets late blight) can carry the disease through the winter. Be sure to destroy any volunteer potato plants that come up. If you plant potatoes again, be sure to buy seed potatoes that are certified as disease-free," Smith says.

Ideal conditions for late blight development are warm, humid days followed by cool night temperatures with heavy dew, fog, or light drizzly rain that persists through morning. Heavy overcast skies during the morning prevent temperatures from rising rapidly and the foliage remains wet. In moist weather, this fungus can be carried 20 miles or more by strong winds and rain.

On older plants, the fungus causes irregular, rapidly enlarging, water-soaked, pale green to greenish-black lesions, which usually start at the margins or tips of the leaves. In dry weather, these lesions turn dark brown, dry, and wither. A pale green 'halo' often surrounds affected leaf areas. The spot may enlarge until entire leaflets are killed.

Lesions can expand rapidly and result in extensive, if not complete, defoliation within 2 weeks. Severely affected plants may appear as if damaged by frost. Infection of both green and ripe fruit starts at the stem-end or the side of the fruit, and soon spreads over the entire fruit. Infected areas are dark green, brown, or brownish black and greasy-looking, with a firm but slightly wrinkled surface.

Successful disease control involves several steps. Smith offers the following guidelines to insure a healthy crop.

  1. Crop rotation is recommended every year. Don't plant solanaceous crops (tomatoes and potatoes) in the same area more often than once every three or four years. Destroy any volunteer plants. This will prevent buildup of disease organisms in the soil.
  2. Purchase only disease-free plants from a reliable grower.
  3. Allow adequate space between plants to increase the rate of evaporation of water (rain or dew).
  4. Harvest all ripe fruit at each picking. Ripe fruit left in the garden may decay and infect the remaining fruit.
  5. Don't cultivate or work plants when foliage is wet with dew or rain. The organisms spread under these conditions.
  6. Apply recommended fungicides according to label directions where the above measures fail to provide adequate control. Contact your local University of Illinois Extension Office for recommended fungicides.
  7. After harvest is complete, spade or plow under, compost, or burn all tomato vines. Destroy all potato cull piles, volunteer plants, and solanaceous weeds such as groundcherry, horse nettle, nightshade, and Jimson weed.



Growing Herbs in Containers Thu, 21 Jun 2018 12:02:00 +0000 This blog post is written by Extension Educator Kari Houle, 217-357-2150,


Got a green thumb but inadequate space or sun for an in-ground garden? Container-grown herbs may be the answer, according to University of Illinois Extension horticulture educator Kari Houle. With the right size container and appropriate potting mix, she says, anyone can grow an herb garden.

"When I was renting apartments in college and graduate school, I didn't have the option to have an in-ground garden. Therefore, I used containers to grow my herbs and vegetables. It's also an easy way to get started with gardening if you've never tried it before. Small-scale growing in containers makes things seem less overwhelming than a huge herb garden," Houle says.

Some herbs, such as mint, are actually better to grow in a container, due to their aggressive tendencies. But it's possible to take a hybrid approach, growing the mint in a container and sinking the whole thing in the ground. That will help control the root system and contain spread. Houle says, "Mint, aka The Mint Monster, can quickly take over if it's allowed to run rampant and go rogue. Make sure to keep it under control if you do place it in the ground."

When selecting containers in which to grow your herbs, select ones that have drainage holes and that are also large enough to accommodate a fully grown herb plant. Containers without drainage holes lead to a higher chance of overly moist soil and root rot. If you do fall in love with a container without a drainage hole and it's not possible to make one, you can use it as a cachepot: a cover for the real container the plant is growing in. Houle suggests taking the inner pot out to water and allow to drain before putting it back in the decorative container.

"When selecting potting mix, don't use topsoil as it's too heavy," Houle says. "Select a nice quality potting mix instead."

These potting mixes are a blend of soil-free materials and are lightweight, making them perfect for use in containers. Often people will ask if they can reuse the potting mix year after year and the answer is mostly yes. If there were no disease issues the previous year, you can reuse the mix, but you may need to add additional nutrients to replace what was lost. You may need to add some new potting mix each year, but eventually it will all need to be replaced.

When deciding whether to start from seeds or buy plants, some are easier to start from seed than others. Herbs such as basil, parsley, chives, sage, cilantro, and dill are all easy to grow from seed, but it's easier to purchase already-started lavender, mint, and rosemary plants. When selecting plants, make sure they are healthy and free of any evidence of insects or diseases and choose those herbs that you know you are going to use in the kitchen.

"As for when your herb plant is ready for harvest, it depends on the plant. You want to make sure they have enough growth on them that you won't shock them by removing plant material and also never harvest more than 1/3 of the plant at a time. The best time of day to harvest herbs is early morning after the dew has disappeared and before the heat sets in." If you want to use fresh herbs in your cooking instead of dried, it's a 3 to 1 ratio of fresh herbs to dried herbs. If the recipe calls for 1 teaspoon of dried herbs, you would use 1 tablespoon of finely chopped fresh herbs.


Blackberry and Raspberry Summer Tipping Tue, 19 Jun 2018 12:00:00 +0000 This blog post is written by Extension Educator Andrew Holsinger, 217-532-3941,


Blackberry and raspberry gardeners can achieve a huge boost in berry yield by learning a technique known as tipping, according to a University of Illinois Extension horticulture educator.

"Summer is a time for tipping blackberries and raspberries," says Andrew Holsinger. "Tipping allows for lateral branches to grow, allowing for three- to five-fold higher fruit yield. Tipping, also called pinching, is the removal of the top 2 to 3 inches of the primocane – fresh growth from the current growing year. The removal of this portion of the plant stimulates lateral bud break."

Blackberries and raspberries, both types of caneberries, are popular small fruits with similar management strategies. These plants have similar growth and fruiting characteristics but Holsinger says some distinctions are necessary depending on the variety.

Removal of the shoot tip when it is of a small diameter and easily pinched by hand leads to a smaller wound, thus less susceptibility for disease infection. Tipping at this stage of development is referred to as soft tipping, but Holsinger advises to still use caution and wear protective clothing and gloves because some varieties have thorns.

"Although the optimum time to tip the shoots is while they remain smaller and unlignified or non-woody, hard tipping can also be an option," says Holsinger.

Hard tipping occurs when the tissues have lignified and become hardened. A pair of pruning shears or loppers will be necessary. Bypass pruners allow for a cleaner cut and are recommend over anvil pruners.

The height to which the primocanes are tipped is somewhat subjective. There are both primocane-fruiting cultivars, which produce fruit in the first year, and floricane-fruiting cultivars, which produce fruit in the second year. Primocanes (first year canes), should be tipped according to their vigor and when they reach the height of the trellis, if applicable.

Follow these general tipping recommendations:

  • Red raspberries do not require tipping.
  • Vigorous thornless blackberries should be tipped when they reach 40-48 inches
  • Black and purple raspberries should be tipped no higher than 30-36 inches, with the exception of purple raspberry cultivars like 'Royalty,' whose growth habit is similar to its red raspberry parent.
  • For floricane-fruiting blackberries (for erect/semi-erect cultivars), tip primocanes at 45-50 inches.
  • Primocane-fruiting blackberry cultivars may be double tipped: once the main cane reaches 25-30 inches, and again when the laterals reach 25-30

Tipping and other pruning should be done in dry, clear weather so the wounds have a chance to heal before rain is expected. Clean pruners with a ten-percent bleach/water solution or rubbing alcohol to prevent the spread of disease between plants.

"Following good cultural practices like proper sanitation, adequate air circulation, and cane management will help to prevent disease," says Holsinger. "Scouting is an important tool to find diseases or viruses early."

Scout caneberries often to determine the length of canes. Some vigorous cultivars need to be tipped multiple times. Laterals can be shortened in the dormant season and usually provide for larger fruit size.

According to Holsinger, "It is important that the tip be removed to the proper height even if the cane has grown further than anticipated. The laterals will develop the fruit and it is preferred to have the crop within picking distance."