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- Food for thought – Insects on the menu
- Be on the lookout for new uninvited house guest.
- Holes in trees – wood borer or woodpecker?
- Little bulbs yield major reward in spring
- Trial Plants winners for 2016
- Yellowjackets – insects with attitude
- Saving Seeds from Favorite Garden Plants
- Time to sign up for the Master Gardener program
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The Homeowners Column
Watch Out for Problem Trees
Extension Educator, Horticulture
Problem child–everybody has one, knows one or is one. Problems predictably follow them along with the headaches. Perhaps problem children just haven't found their niche where they can flourish. Some trees seem like problem children with their dropping twigs, diseases and bug problems. Actually the trees are not bad trees, we just haven't placed them in a situation where they can flourish.
First of all, select the right tree for the right spot. Give power lines plenty of clearance from large trees. You do the math. A tree with a mature height of 80 feet will soon engulf a 30 feet tall power line.
Secondly, when planting trees do some homework to determine the common problems associated with a tree selection. Just wanting fast shade is not a good reason to plant a problem child unless you are planning to remove the tree once a more desirable tree gets larger. With proper care such as watering during drought periods, mulching and regular fertilization, durable trees can be planted and will provide fairly quick shade.
Many trees should not be planted as shade trees in lawns, but are usable trees around ponds and in less manicured areas. They can also provide wildlife habitat and food in natural areas.
Don't plant problem children without careful thought. If you have inherited a problem tree, get to know a certified arborist who can evaluate the tree. A few problem children include:
|Silver Maple||Probably one of the best trees for areas with very poor soil and poor growing conditions where few other trees would survive. However, they can cause sidewalks to buckle and can clog drain tiles. Silver maples are very fast growing which means weak wood and limbs all over the yard from wind, ice and snow damage.|
|Sycamore||Like most kids, they are always dropping something. They have leaves like shoe leather (from a very large shoe). The tree continually sheds its outside bark in summer. They can reach 100 feet tall with an equal spread - much too large for a street tree and for most lawns. The regular infection of the fungal leaf disease, anthracnose, keeps sycamores bare of leaves until mid to late June and causes twigs to continually fall. Sycamores are magnificent trees situated along rivers and in flood plains, which is where they should stay.|
|Siberian Elm||Numerous diseases, brittle wood, elm leaf beetle and just plain messiness with no ornamental attributes. I'm having a hard time determining the redeeming value of Siberian elms. Firewood, perhaps?|
|Green Ash||Narrow branch angles, prone to storm damage, ash borer, ash decline disease.|
|European White Birch and paper birch||Prone to bronze birch borer insect, prone to storm damage, needs high soil moisture. Consider superior cultivars such 'Hertiage' and 'Whitespire.'|
|Birch, River||Leaf yellowing due to iron deficiency, tends to drop twigs, susceptible to storm damage.|
|Black Locust||Borers, root suckers, weedy seedlings.|
|Bradford Pear||Poor branch structure, too many branches arising from common site on trunk, narrow branch angles, tends to split apart as it ages, needs regular pruning to develop structure.|
|European Mountainash||Borer insects, fire blight disease.|
|Pin Oak||Iron deficiency in alkaline soils.|
|Scotch Pine||Pine wilt disease.|
|Lombardy Poplar||Canker disease.|
|White Poplar||Root suckers.|
|Princess Tree||Brittle wood, drops leaves, twigs, flowers and seeds. Flower buds often get killed by frost in central Illinois.|
|Russian-olive||Canker and verticillium fungus wilt disease.|
Biological Pest Control Workshop
Thursday March 16, 9 am-4pm. Discover the wonderful world of beneficial insects that can help us control garden pests. Cost is $35 per person or $45 for couples. Cost includes many publications. Call 333-7672 for information.