New Plant Hardiness Zone Map in 2012

This has certainly been an unusually warm winter so far. Many people are concerned that the warm temperatures will results in plants sprouting too soon or in heavy summer insect problems.

Some people wonder if our climate is changing due to various factors, including global warming.

Source: Illinois State Climatologist  

The USDA released their new Plant Hardiness Zone map recently. The 2012 changes show that we are indeed experiencing overall warmer winter temperatures.

The USDA hardiness zones are based on average winter minimum temperatures. According to Jim Angel, Illinois State Climatologist at the Illinois State Water Survey, “This is certainly an improvement on the old USDA map that was based on data from a relatively short and cold period from 1974 to 1986.” Angel says that the new map is based on a longer period that includes the milder winters of the 1990s and early 2000s.

The new map can be found at http://planthardiness.ars.usda.gov.

To reflect these milder winters, most zones have shifted northward. Angel says, “Here in Champaign I used to be in the middle of Zone 5 according to the old USDA map. Now I'm almost in Zone 6.”

These maps are a useful guide. Most garden catalogs list the hardiness zone rating for their plants. The hardiness zone is an important plant selection guide, but it is only one factor in determining if a plant will survive the winter. Other factors, such as moisture levels and critters (voles, rabbits, and mice), also affect a plants chance of winter survival.

Speaking of critters, will this mild winter affect insect populations this summer? According to Phil Nixon, Extension Entomologist, mild winters or cold winters have little effect on the number of insects that people typically notice.

Nixon says that it is true that in a mild winter, more pest insects survive, but so do more predatory insects, parasitic insects, and other natural enemies. Contrary to popular belief, Nixon says that the most important impact on insect numbers is spring weather. Cool, damp springs encourage the development of fungi that attack insects and slow the development of insects. The result is fewer caterpillars and other insects surviving through the spring.

And finally, if you have daffodils sprouting or plants leafing out early, don’t fret. Although some of the early growth could experience freeze damage later, the plants should be fine overall once our official spring finally arrives. You can add a layer of mulch over the sprouting plants to provide additional winter protection, but it is probably not essential.

Published in Canton Daily Ledger Column 2-4-2012

Removing Tree Stumps

Recent droughty summers, a cold winter, and various other environmental and pest problems have killed many trees in our area. Usually when a tree is removed a stump is left behind. Here are several suggestions on how to remove tree stumps easily, quickly, and economically.

According to Bob Frazee, retired University of Illinois Natural Resources Educator, the cheapest and easiest method of removal, although not the quickest, is to cut the stump at or below the ground level, cover it with soil, and keep the soil moist. Decay organisms will then rot the wood. Grass may be planted in the soil if the thin layer over the stump is kept moist during dry seasons. The decaying method may be hastened by boring several vertical holes in the stump before it is covered with soil. This method may be used any time during the year. 

Frazee says that stumps may also be burned out. However, before burning stumps, be sure to check your local ordinances to see whether open burning is permitted. Frazee suggests that stumps may be burned out rather quickly with charcoal or coal by making a “stove” from an empty 5-gallon metal container. A stove is made by removing the bottom and top from the can and punching 4 to 5 one-inch holes in the side near the bottom. Place the stove on top of the stump and build a fire in it. A hot fire is required to burn out stumps, since the wood absorbs moisture from the soil and burns like green wood. Stumps will burn best during dry seasons.

Grubbing or digging out stumps is another option, according to Frazee, but it is hard work. Stumps larger than 15 inches in diameter are usually rather difficult for the average person to remove.

A popular option for homeowners to explore is use of a commercial stump grinder. Mechanical stump grinders that chip the wood are available from some landscaping firms, tree removal services, and some community street departments. A stump-cutting or grinding machine is often the quickest and most satisfactory means of removal. It can chip out a stump to 8 or 12 inches below ground level in minutes.

Stump removal is not easy. Many people resolve to leave the stump and let it decay naturally. Chemicals are available that can help speed up the decomposition process. Instructions for stump removal chemicals will vary from product to product, but all require drilling several holes in the stump. A measured amount of chemical is poured in each hole, and then water is added to fill the holes. Let the mixture stand for four to six weeks. Repeat applications may be necessary.

Sometimes the decaying stump is included in the landscaping. I saw a stump used as a miniature fairy garden recently that was really cute. Try adding containers on top of the stump for a different look. I once put a wooden wheelbarrow filled with annual flowers on a stump and added more annual flowers around the stump. Use your imagination and you may find leaving the stump is a good option.

If the tree is not completely dead when it is cut down the stump may produce sucker growth. You have two options to solve this problem. The quickest solution is to immediately treat the cut surface with an herbicide. You can also cut off all new sucker growth before it reaches eight inches to gradually deplete the stored food, but this can take five to ten years to be completely effective.

Finally, remember that dead trees are an important part of our ecosystem. Many birds and small mammals nest in dead trees. Consider leaving the tree if it is located in an area where it won’t be an eyesore or cause safety issues over time.

Originally Published in Canton Daily Ledger Column 6-21-2014; News Release 6-24-2013

Sticky Plants are Annoying

While hiking recently I got to thinking about the various plants that stick to our sock and pants. Certainly, they are frustrating; but, as a plant geek, I wanted to know more.

Sticky plants attaching to clothes, hair, fur, and feathers to disperse their seeds into new areas. They do this with hooks, spines, barbs, and burrs. Let’s look at a few common examples that we find here in central Illinois.

The biggest challenge on my property is Spanish Needles (Bidens bipinnata). This weedy plant grows one to three foot tall in dry, shady areas. Its leaves are finely textured, looking a bit like flat-leaved parsley. The non-showy, yellow flowers develop into 2-4 prong, barbed fruit. They get their name from the fruit’s needle-like prongs, each with its own backward pointing barb.

Virginia Stickseed

Virginia Stickseed (Hackelia virginiana), also called beggar’s lice, has very small prickly bur fruit that clings to clothing. It grows one to four foot tall in dry woods. The burs are less than ¼” in size. Burs are arranged along one side of stems (racemes) that are held 2-8” above the plant.

Probably the most commonly known hitchhikers are burdock and cocklebur. In fact, Velcro is said to have been designed after the burs of the burdock plant. After a hunting trip, the inventor looked closer at the tiny hooks on the bur and created the hook and loop fasteners design.

Cocklebur

Burdock (Arctium sp.) is a robust plant. It is also called wild rhubarb due to its large leaves that can reach 20” long. This is a biennial plant that grows rhubarb-like leaves the first year. In the second year, it sends up 2-5 foot stalk with large egg-shaped leaves and ½ to 1” bristly purple flowers. Each fruit is a prickly, clinging bur. Unlike rhubarb whose stems are edible, burdock has an edible taproot.

Cocklebur (Xanthium sp.) is related to burdock. This plant sprouts from seed each year, reaching 2-5 foot by summer’s end. Its triangular, lobed leaves are 2-6” long. Cocklebur has both male and female green colored flowers. Female flowers form ½-3/4” burs that are held in the axils of the leaves. The football-shaped burs cling with hook-tipped prickles.

Bedstraw

Bedstraw (Gallium sp.) is sometimes called velcro-plant or stickywilly. Bedstraw attached to us in two ways. Its leaves and stems have fine hook-like hairs that cling to clothing and fur. However, it is the extremely small seeds that really create havoc. At less than 1/25 of an inch, the seed burs are covered with small hooked bristles. Because each plant produces hundreds of seeds, they quickly cover large areas of clothing. Their small size and abundance make them difficult to remove.

There are many more, but you get the idea. I have not developed a magic way for removing these from my clothes or pet’s hair. Washing clothes does not remove most hitchhiker seeds. They usually need to be picked off individually, though some can be scraped off with a butter knife.

Enjoy a fall hike in the woods, but try to avoid those hitchhikers!

Published in Canton Daily Ledger Column 11-4-2017

Trees in Winter

Each season brings a different look to the garden. I enjoy each one, but I must say that plants are uniquely beautiful in winter. Now is a great time to see a plant’s texture and form - each unique and mystical.

left to right: Silver maple, red maple/dogwood, & redbud 

Look for the differences between these trees this winter: oak, maple, and redbud. Oaks are the kings of the forest. They soar well above the maples and smaller redbuds. Oaks are majestic in size and texture.

The white and bur oak are most majestic. A white oak will grow well over 100 feet tall in the wild. It has a medium to coarse texture in winter, but the wide-spreading branches exhibit a strong, bold appearance. Bur oaks are a bit more coarse in texture and probably even more majestic with massive trunks and stout branches.

There are many different types of oaks though. A pin oak is much different from the white and bur. Although still medium to coarse textured in winter, a pin oak has a strongly pyramidal habit. It is a strong central leader and pendulous lower branches. My college classmates called this the 55-mile per hour tree because we could recognize it even at highway speeds.

Maples also come in many different shapes and sizes, from the dainty amur maple to the sturdy sugar maple to the weak silver maple. Sugar maples grow 60 to 75 feet tall with a rounded character. They are hard, sturdy trees. Their texture is medium in winter. Notice their beautiful bark, which with age becomes deeply furrowed, with long irregular thick plates or ridges.

Silver maples are very popular because they grow fast. Unfortunately this is not always a good trait, since fast growing trees are usually also weak-wooded, often breaking in wind and ice.

The silver maples grow a bit more oval than rounded and are a bit coarser in the winter, often looking disheveled.

Amur maples and redbuds are similar in that they are both small, understory trees. The amur maple is a small tree or sometimes a multi-stemmed shrub, but is usually round shaped. It has very slender, fine branches and thus a medium-fine texture.

Redbud is a small tree with medium winter texture. Although best known for its spring flowers, it also has interesting bark in winter. The older bark is black or brownish with orange inner bark peeking through.

Enjoy looking at trees this winter. Also notice how terrible the topped trees look! Please do not top trees. It results in very weak, ugly trees!

Originally Published as: Ledger Column 1-8-2000, 1-5-2013; News release 1-8-2018

Food Garden Safety Begins with a Lead Test Soil

The garden season is in full force, and I’m excited to hear about all the food and community gardens happening in our area. As we begin growing food and other plants this summer, please consider some potential health hazards.

Forest Hill Community Garden in Peoria, IL

A growing concern in urban soils is lead contamination, though suburban and rural soils may also be contaminated. I recently partnered with the Peoria City/County Health Department to highlight the importance of avoiding lead contaminated soil during the gardening season.

Some garden soil contains high levels of lead that can pose a serious health risk. The risk can be from contaminated garden soil brought into the house on clothing, shoes, tools, or clinging to vegetable crops. Soil becomes mixed with house dust that is inhaled or ingested, resulting in lead poisoning. Roots crops (carrot, radish) are more likely to contain high lead levels than fruiting (tomato, pepper) and leafy (lettuce, spinach) vegetables. The harmful effects of lead poisoning can cause lifelong problems such as learning disabilities, behavioral problems, and lower IQ 

Gardeners can reduce the risk of lead poisoning by following safe gardening recommendations. A good start is with a soil test to determine if the soil is contaminated with harmful lead levels. Garden soils can be contaminated with lead found in old house paint, old lead plumbing pipes, or old leaded automobile fuel. The greatest lead concentration is in the top 1 to 2 inches of soil.

Soil samples should be taken from several areas to determine the location of the contamination. Sample children’s play areas and vegetable gardens separately. With a trowel or shape, take several soil samples from within the chosen area. Combine the samples together, break up clods and mix the f soil thoroughly.

Use about one pint of the soil mixture as a sample to send for testing. Discard the remainder. Send samples to a soil testing lab with a special request for lead testing. Be sure the lab you choose does lead testing.

Gardeners can reduce the risk of lead poisoning from lead contaminated soils by growing food crops in raised beds. Covering ground at the bottom of an eight-inch high raised bed with landscape fabric, then fill with a good potting mix. Avoid using chemical treated lumber.      

More information on how to grow food safely in the home vegetable garden is found on the University of Illinois Extension Lead in Soils Resources website. In addition to a Lead in Garden Soils factsheet, there is also information on soil testing, soil labs, general gardening, other soil contaminants, and more.

Published in Canton Daily Ledger Column on 6-17-2017

Test Yard and Garden Soil Before Adding Amendments

Fall is the time to take soil tests. If you have plants that are not growing the way they should, a soil test might be needed to see if soil amendments are needed.

Fertilize Lawn Based on Soil Test Results

Soil amendments should be based on a soil test to know the amounts needed. Be sure the sample is representative of the area to be treated. The teaspoon of soil finally used for analysis weighs a few grams in comparison to about 50,000 pounds of soil per 1000 square feet to a six-inch depth.

Before sampling the area, size it up for differences in soil characteristics, such as color, texture and drainage. If these features are uniform throughout the area to be treated, a single composite sample of the topsoil is adequate. If there is great variation in these features, take a composite sample from each predetermined area.

Soil samples may be taken at any time of the year when temperature (soil not frozen) and moisture conditions permit. Late summer and fall sampling is a good choice based on factors affecting nutrient availability and time available to the gardener.

Within the area selected for a sample, dig a hole to spade depth. With a shovel or trowel cut a thin slice down one side of the hole. Place this slice in a pail or pan. Do not include sod roots. Repeat this procedure in at least eight well-scattered spots within the chosen area. Place each slice in the pail with those previously taken. Break up clods and mix the slices of soil thoroughly with the hands and by revolving the pail while held at an angle of 45 degrees. Use about one pint of the soil as a sample. Discard the remainder.

The sample is then sent to a soil testing lab. University of Illinois Extension has a listing of labs online at https://web.extension.illinois.edu/soiltest/.

Soil testing and fertilizer application is only one step in effective soil management. For best growth of lawns, vegetables and ornamentals, you should also provide the proper soil structure and soil moisture. Take time this fall to focus on good soil health, because soil management is essential for good plant growth.

Published as News Release on 11-7-2011

Recycled Leaves Make Inexpensive Mulch

Fall brings wiener roasts, festivals, and leaf removal. I suggest making good use of the fallen leaves in your yard.

Ginkgo in Fall

The tree leaves that accumulate in and around your landscape represent a valuable natural resource that can be used to provide a good source of organic matter and nutrients for use in your landscape. Leaves contain 50 to 80 percent of the nutrients a plant extracts from the soil and air during the season. Therefore, leaves should be managed and used rather than bagged or burned. According to Rhonda, there are four basic ways in which leaves can be managed and used in the landscape.

First, a light covering of leaves can be mowed. Simply leave the shredded leaves in place on the lawn. This technique is most effective when a mulching mower is used. In fact, during times of light leaf drop or if there are only a few small trees in your landscape, this technique is probably the most efficient and easiest way to manage leaf accumulation.

Second, mulching is a simple and effective way to recycle leaves and improve your landscape. Leaves can be used as a mulch in vegetable gardens, flower beds and around shrubs and trees. Leaves that have been mowed or run through some other type of shredder will decompose faster and are much more likely to remain in place than complete leaves. I use a chipper shredder vacuum to pick up my leaves, which I use instead of purchased mulch in my landscape beds.

Third, leaves may be collected and worked directly into garden and flowerbed soils. A 6 to 8 inch layer of leaves tilled into a heavy, clay soil will improve aeration and drainage. The same amount tilled into a light, sandy soil, will improve water and nutrient holding capacity. A recommended strategy for using leaves to improve soil in vegetable gardens and annual planting beds is to collect and work them into the soil during the fall. This allows sufficient time for the leaves to decompose prior to spring planting. Adding a little fertilizer to the soil after working in the leaves will hasten their decomposition.

Finally, try composting your leaves. Compost is a dark, crumbly and earth-smelling form of organic matter that has gone through a natural decomposition process. If you have a garden, lawn, trees, shrubs, or even planter boxes or houseplants, you have a use for compost.

Get extra value out of your leaves this fall. And for fun, don’t forget to jump in the pile once!

Watch my video on Fall Leaf Management.

Published as New Release on 10-6-2014