Over the Garden Fence Where gardeners come to find out what's happening out in the yard. Sun, 15 May 2005 13:02:08 -0500 https://web.extension.illinois.edu/dkk/eb192/rss.xml How Many Times can We Talk about Water? https://web.extension.illinois.edu/dkk/eb192/entry_13535/ Fri, 17 Aug 2018 07:44:00 +0000 https://web.extension.illinois.edu/dkk/eb192/entry_13535/ Master Gardener Help Desks continue to get visitors and calls about failing plants. Large evergreens and older shade trees have issues since the drought of 2012 and continue to show signs of stress, long-term decline and eventual death. Homeowners can see this visually in the rates of annual growth and the size of foliage on the trees. It will show up in the spring as terminal branch and twig dieback too. Some deciduous trees will manage water loss by allowing some of the foliage to yellow and fall to the ground. Birch trees are a good example of this. They also will drop damaged leaves from the Japanese beetle, so both are happening right now. If a tree has been lost, you can likely see the decline by looking at the annual rings after the tree is down. More recent rings are closer together compared to those pre-2012. Shade trees, shrubs and evergreens do not show water stress like other plants and that's' why it is easy to think they are OK.

Perennials in the beds will show stress by wilting during the day and recovering by morning, only to wilt again if water is not supplied. Blooms will not last as long and will not have the quality you expect. Full sun perennials will wilt before plants in the shade, but eventually those perennials, including ground covers, will wilt.

If the lawn is the problem, the best time to renovate between August 15 and the first week in September. This puts the renovation in a timeframe when the weather will only be getting better for lawns as we move to cooler and better moisture conditions. If weed control is going to be part of the renovation, even the weeds need to be actively growing for control products to work well. Fall weed control can be done into October, if necessary. Water will be key for the revival of dormant grass plants and the germination of seed if over-seeding or reseeding selected spots.

Related to the drought is the fact that while Japanese beetles are moving from the feeding portion of their life cycle to one of egg laying, the very hard dry soil will limit egg laying and for those eggs that do hatch, the ability to acquire enough food to survive the winter. If there has not been a history of grub damage, the rule of thumb is it takes more than 12 grubs per square foot before real damage is done to the lawn.

Tree and Shrub Disease Update https://web.extension.illinois.edu/dkk/eb192/entry_13534/ Mon, 13 Aug 2018 11:37:00 +0000 https://web.extension.illinois.edu/dkk/eb192/entry_13534/ It happens every year, almost like clockwork. (I say "almost" because not every tree leaf disease shows up every year.) Another good point to make right way is common leaf diseases are rarely fatal to a tree.

Some of our common tree leaf diseases are: Anthracnose, often seen on sycamores; and Apple Scab and Cedar Apple Rust are very likely on fruiting apple trees and the ornamental flowering crabapples. A more recent leaf disease, Tar Spot on maples, has made its presence known in the last three to five years. And, while rose growers are very familiar with Black Spot on rose foliage, others may be used to Powdery Mildew on Lilacs and Phlox.

What they all have in common is weather. Leaf diseases are not as common and the infections not as bad when we have drier, warmer springs. The fungal spores that infect the leaves cannot travel in the air and still be viable in those hotter, drier temperatures. This was certainly not the case for the spring of 2018. There is a natural decline of infections as our normal spring weather starts to warm and the rains are less often. You easily can see this on flowering crabapples once the infection period ends; you see the new growth at the ends of the branches looking good, while the first leaves of the season are spotted or have fallen from the tree.

If you have an established landscape with disease-prone ornamentals, you will have to manage those leaf diseases appropriately. As you have the chance to update and replace plants, just like we do for vegetables, choose a naturally disease-resistant replacement. There are disease resistant plants for every leaf disease listed here. One point to remember, these plants are only resistant to leaf disease, not immune. In a normal season, they can appear quite free of disease. In a year where disease pressure is high, you are likely to see some spotting. Resistance can mean the plants do not allow infection in the first place. If infection occurs, the plant is able to confine that infection and does not allow it to enlarge.

There may be key plants in the landscape that make a focal point in the yard or maybe there is a tree next to the patio that you do not want leaves raining down from all summer. Fungal diseases must be treated in a timely manner and can only be prevented. There is no catching up if you miss those first sprays. Knowing that fungal spores are out there at the time of bud break is key. It will not be comfortable at that time of year, so you will need to "bundle up" a bit. Sprays are directed at the buds as they swell and begin to lose the over wintering bud scales to show the very first green tips of the new growth emerging.

A large shade tree can have spot diseases, but it is not one to treat due to the size. Many times, it is the lower limbs that exhibit the leaf diseases while the upper canopy is fine. One strategy is to spray as high as is possible with the equipment you have.

So, take note for 2019 if you want to incorporate disease prevention measures in the future.

Poisonous Plants https://web.extension.illinois.edu/dkk/eb192/entry_13515/ Thu, 02 Aug 2018 20:58:00 +0000 https://web.extension.illinois.edu/dkk/eb192/entry_13515/ You would not think of intentionally planting poisonous plants in the home landscape, but that is exactly what the University of Illinois - College of Veterinary Medicine has done on campus, and for good reason. They have created an actual garden to grow poisonous plants. Each year, farm livestock, recreational horses and our pets are accidently exposed to plants that harm to some level. The Vet Med garden is there to assist livestock owners and the homeowner with pets and children in identifying harmful plants on the farm and in the home landscape.

This past spring during mushroom season, University of Illinois Extension received weekly calls from worried pet owners suspecting ingestion of mushrooms. It was important that they take their pet to the vet immediately for treatment.

In the brochure that accompanies the Poisonous Plant Garden, Veterinary Medicine has information everyone should know. "The toxic effects of plants vary with the health status, age, and species of the animal affected. Time of year, humidity, growth conditions, and plant growth stage, among other factors, influence a plant's toxicity."

A common example would be poison ivy, where we break out with rash and blisters. Even in the wintertime, what little sap that remains in the woody stems can still give us a mild rash. During the summer and active growth, our skin fares far worse. Another example would be rhubarb; we love the pies, but do not eat the leaves.

Additionally here are some very helpful pointers if you feel a pet or family member has ingested a poisonous plant:

1. Obtain a sample including all parts of the plant (especially those parts ingested).

2. Estimate the quantity eaten.

3. Estimate frequency and duration of exposure, and time of onset and nature of clinical signs.

4. Contact a physician or veterinarian immediately.

The garden includes 22 plots, which contain 80 different plants that have properties that cause mild distress to severe reaction or worse. There are dozens of commonly planted trees, shrubs, evergreens, perennial flowers and weeds growing and listed. A lot of what is there is perennial, yet each spring they will plant annuals too. Not every plant part of every plant is toxic. It is often leaves of course, but also unripe or ripe berries, stems and, for some, the roots. The College of Veterinary Medicine also includes tropical plants we grow as houseplants as our pets will chew on them too.

For your pet, besides contacting your veterinarian, ASPCA Animal Poison Control Center has a website at aspca.org/pet-care/poison-control. For large animals, contact your local Vet or the Veterinary Medicine Emergency Room at 217-333-5300. For family members, contact the Illinois Poison Control Center at 800-222-1222.

Watering Hanging Pots and Containers https://web.extension.illinois.edu/dkk/eb192/entry_13500/ Wed, 25 Jul 2018 16:01:00 +0000 https://web.extension.illinois.edu/dkk/eb192/entry_13500/ For best bloom show and performance, the big deal is never to let the plants wilt. Yes, they recover but a future cost of less produce or less ornamental flowers. If left to wilt, a portion of the roots are lost and often with that there is the loss of some foliage and early flower death. Plants recover, but energy will be directed to rebuilding roots instead of blooms. Before hanging pots wilt, the pots get lighter (remember water weighs about 8 pounds per gallon). Use your index finger and eyes as a moisture monitor; the soil mix will feel dry, and the soil may pull away from the edge of the pot. The same goes for the larger containers, though not many gardeners actually pick up those large containers to see how light they are.

The best way for plants to receive water is directly to their roots, whether using a watering can or a garden hose with a water breaker. This has an added benefit of keeping leaf surfaces dry to prevent diseases. This is especially important on the vegetables, like tomatoes. Watering early in the morning will ensure enough available water during the hotter parts of the day. However, if returning home at the end of the day and plants have wilted, water immediately. Do not wait for the next morning; plants will take up water during the night. If you wait until morning, wilted plants will struggle to recover all day long in the sun. Big plants in small containers or hanging pots often will need to be watered twice a day. Those larger containers have more soil mix allowing a longer buffer between watering. Other signs of uneven watering with container vegetables will be uneven growth of fruits. Cucumbers will have that fat/skinny look, bean pods will develop with an uneven appearance and tomato fruit skin will crack and split.

Not all is lost when it comes to keeping pots and containers evenly moist. Many potting mixes now contain water-retaining gels that absorb lots of water and later give it up as the soils dry. Potting mixes also are designed to drain well to avoid getting waterlogged, which damages roots and can cause crown rots killing the plants. When you do water, make sure there is enough water to drain out the bottom. For hanging plants that is easy, less obvious for container plants. A note of caution here, when the soil mix dries and pulls away from the sides, water will run down the edge of the pot and drains away quickly. A follow-up watering often is needed to be sure the soil mix rehydrates and swells back out to the edges.

Now We Need to Water https://web.extension.illinois.edu/dkk/eb192/entry_13491/ Tue, 17 Jul 2018 14:59:00 +0000 https://web.extension.illinois.edu/dkk/eb192/entry_13491/ What a difference just a few days can make in what we need to be doing in the home landscape. Since the rain shut off or slowed, the first part of the landscape with symptoms of water stress is the lawn (even the lawn weeds). If you planned for it, go ahead and let the lawn go dormant even though it is early in the summer for that to happen. If your fertilizer program is to feed all summer, then plan to water to take advantage of your fertilizing efforts.

It will take 680 gallons of water to put down 1 inch of water per 1000 square feet, if you are using your meter reading to know when to move the sprinkler to the next section of your lawn. Using any straight-sided container, such as a tuna can, is a good alternative for measuring water output. Be sure to check with your local authorities for any water restrictions. Most often are those rules guiding you on which days of week you can water using the homes address, even or odd numbers. Often, watering is allowed early in the morning and in the evening. That is 6 hours every other day, way more water than you are going to need to keep your lawn well hydrated.

When it comes to watering your landscape plants, consider any new plantings done in the last two years as a starting point. Those plants are not yet established, and they greatly benefit from water during droughts, even if they are brief. If the watering berm is still in place, continue to use that. If a berm is not an option, leaving the hose at a slow rate of flow around what used to be the berm works too.

The next set of landscape plants to consider would be those large established trees and evergreens. We do not think of a tree wilting, yet next years' potential growth is dependent on how well it does this year. The best "zone" to water is just inside to just outside the canopy drip line. This is where the tree has a lot of roots to absorb the moisture during a natural rain event. Big evergreen trees have a similar set of roots as well. A more effective way to water these big trees is to use the open hose, moving it around under the drip line area at a rate of flow that puts on a lot of water without running off.

A preferred strategy would be to use those permitted hours to water the lawn and garden or flower beds in the morning. Watering early morning will allow foliage to dry off before any disease has a chance to develop. Use the evening hours to water the trees and evergreens where the water is only on the ground.

If you have to choose between watering the lawn and those established big trees and evergreens, chose the big plants over the lawn. Lawns can be repaired, renovated and can naturally recover from a drought. You cannot replace the big guys.


A Note to Readers: This summer, we are excited to announce we will be joining our two horticulture blogs – "Over the Fence" and "Down the Garden Path" into one convenient place – and it's right here! The upcoming "Over the Garden Fence" blog will still feature timely topics and helpful hints from expert Richard Hentschel. If you haven't already, you can sign up for email alerts so you won't miss a post (see the blue box in the upper right corner of this page). Thank you for following U of I Extension!


It's OK to blame the weather some more https://web.extension.illinois.edu/dkk/eb192/entry_13484/ Thu, 12 Jul 2018 22:54:00 +0000 https://web.extension.illinois.edu/dkk/eb192/entry_13484/

A Note to Readers: This summer, we are excited to announce we will be joining our two horticulture blogs – "Over the Fence" and "Down the Garden Path" into one convenient place – and it's right here! The upcoming "Over the Garden Fence" blog will still feature timely topics and helpful hints from expert Richard Hentschel. If you haven't already, you can sign up for email alerts so you won't miss a post (see the blue box in the upper right corner of this page). Thank you for following U of I Extension!


The weather this spring caused gardeners and farmers alike to fall behind with tillage and planting in the fields. It also delayed home gardeners in early spring cleanup and bed preparation. The weather eventually came around, if even briefly, to get the crops and vegetables "in."

One outcome of this weather pattern has been all the weeds. Skip a couple of weeks of weeding, and we immediately regret that decision. Annual weed seeds have continued to germinate with the right conditions, and perennial weeds have come back strong, even if taken care of earlier by hoeing or pulling what we could.

Weeds by themselves are bad enough – they compete for resources, gardens look messy, and landscape beds covered in all manner of weeds look unkept. Plus lawn weeds, whether treated or not, do not look good. But, there also are more reasons to hate the weeds.

Calls to the U of I Extension Master Gardener volunteers' Help Desk have spiked as those little bunny rabbits are growing into full sized eating machines. All those weeds provide a great hiding place from predators and while there, they consume some or all of our favorite flowers.

When we are doing our best to grow vegetables, weeds contribute towards two more potential problems. Weeds can "host" diseases without showing any symptoms. They are there ready to spread that disease to our vegetables. That issue is helped by the second potential problem – insects. They will vector the diseases by feeding on the weed, then your vegetable plants.

So for more than aesthetic reasons, it is good to have a weed-free bed. Plus, you also benefit from fewer potential weeds next year since weeds will not be allowed to go to seed and build up the weed seed bank.

What to do now that the weeds are as big as your flowers? If your flowers are perennials, pulling the weeds likely will not disturb the established root systems. Getting the weeds out of the annual flowers takes a bit more finesse. You may have to hoe very shallowly or cut off weeds with clippers close to the flowers instead of pulling so you do not damage the annual flower root system. Same goes for vegetables unless large and established.

The last bit of advice I can share and have so often when discussing weeds is this: even if you have lost the battle, don't lose the war. Do Not Let Weeds Go To Seed!

What is Going on in the Yard? https://web.extension.illinois.edu/dkk/eb192/entry_13452/ Tue, 26 Jun 2018 12:46:00 +0000 https://web.extension.illinois.edu/dkk/eb192/entry_13452/ So many things, only so much space to get them down. I think the weather has been both good and bad, depending on your perspective right now. Lawns usually begin to slow down a bit, as the natural spring flush begins to pass, but as long as the rains continue, grass will continue to grow at an above average rate. The good part is I have not seen a bad looking lawn, park, cul-de-sac or parkway yet. The bad news is keeping up with the mowing is tough between the rain and attempts to follow that one-third rule.

The overly wet soils also are promoting mushrooms, many from rotting roots and decaying landscape mulch. All those Ash tree roots from dead trees, courtesy of the Emerald Ash Borer, have been in the ground long enough now that decay is well underway.

The above average rains are causing some insect problems both inside and out. Inside, homeowners are reporting more ants in the home in general and some specific types looking for food. Dishes of open dry cat food can be found covered with those very tiny tan ants, especially if that dish is always in the same spot. Outside you may find a potted plant not doing so well, only to find out ants have come out of the overly wet soil and brought their eggs with and have taken up home inside the pots, high and dry.

Another very tiny insect is the Thrip. They can be found by the thousands, unexpectedly on yard furniture and even the car. Not really much to do with them, as those populations will soon crash. The weather is to blame again, allowing large populations on our landscape plants and later to be found on all sorts of objects nearby.

Other outdoor pests are mosquitos, and it is tick season. Care should be taken especially for ticks. Your outdoor pets should be routinely groomed to remove ticks not already feeding and to properly remove ticks taking a blood meal. Best to call your vet for more information. If outside a lot, dress correctly. Wide-brimmed hats or at least a ball cap can help keep them out of your hair and scalp. Tuck your pants into your socks and use a rubber band to help seal them out. Do your homework and research how long some of the repellants are effective, some only last a couple of hours, others much longer and none last all day without reapplying. A family "tick check" is not a bad idea either. Mosquitos need water for several days to complete their life cycle. Right now after every rain, go out and empty everything that holds water that could support mosquitos.

Homeowners are also reporting lots of water sprouts and suckers in their landscape plants and sprouting suckers from roots in the lawn many feet away. Water is again to blame. Plants continue to take up moisture and will naturally push that water and nutrition into latent buds, which break and show up as water sprouts and suckers. Crabapples may be the worst, yet all plants do this.