| Greetings!
This month's content was to be a continuation of design guidelines introduced last month. Unfortunately within the past weeks, the long-awaited and destructive emerald ash borer has been discovered in Minnesota, specifically in St. Paul, MN. With this news, I want to provide homeowners information with how to i.d. ash trees, the facts of the disease, and if anything can be done to save your trees.
July's Cattales edition will return to design guidelines covering plant sizing, spacing, and selection.
With the kids out of school, consider a day trip to the Minnesota Landscape Arboretum to check out their summer exhibit, WATEROSITY: GO GREEN WITH A SPLASH. "Waterosity" will celebrate this most precious resource through thought-provoking and playful installations and exhibits. Check your local library for a Museum Adventure Pass for free admission to the Arboretum. |
|
Emerald Ash Borer |
|
  
Above left: Ash leaf Center: Ash flower gall Right: Adult emerald ash borer
Should you be worried about emerald ash borer (EAB)? Even if you don't have ash trees on your property you should still be concerned. Minnesota has one of the highest volumes of ash on forestland in the U.S. with an estimated 900 million ash trees. It hits closer to home if you have them planted in your yard or neighborhood.
How do you identify an ash tree? Ash trees have compound leaves, meaning there are multiple "leaves" (leaflets) attached to a "stem" (petiole). See photo. The trunk will have diamond-shaped areas separated by interlocking ridges. Another clue it's an ash is the presence of ash gall which is not present on all trees. Ash flower gall, caused by mites, is an abnormal growth of the flower which looks like little round brown balls.
All ash trees are susceptible to EAB that attacks and kills the tree. The adults are small, iridescent green beetles that live outside of trees during the summer months. The larvae are worm-like and live underneath the bark of ash trees. Trees are killed by the tunneling of the larvae under the tree's bark.
The beetle only travels two miles a year on its own. However, it has spread due to the transportation of ash wood products such as pallets, firewood, etc.
Symptoms your tree is declining is canopy die-back, woodpecker activity, splitting bark, shoots from trunk and roots, and abnormally larger leaves. Signs to look for to identify it as EAB are:
- "D" shaped exit holes in the trunk
- Serpentine tracks under bark
- Seeing the adult beetle outside the tree or larva under the bark
If you suspect EAB, contact a certified arborist for positive identification and removal or a U of M Forest Resources Extension to find an EAB First Detector.
What can you do to protect your trees? The best way to protect your trees from any disease or pest is to keep them healthy. Insects and diseases seek out trees that are stressed. Plant them correctly. Plant a variety of trees. Prune accordingly and correctly.
There are insecticide options available to treat ash trees, but it may not be effective or economical. Some studies have seen success with treatment prior to attack, but not all. If you live within a quarantined county, Ramsey, Hennepin, and Houston counties are quarantined counties, your trees are at risk. If you live within 10-15 miles of the infestation area, your trees may be at risk. If you live 15 miles or further from a known infestation area, your risk is low and it is too early to consider an insecticide. Talk with a certified arborist to see if this option is viable for you.
You can help slow the spread of destruction by not moving ash products such as firewood from county to county. Infested wood needs to be properly disposed of either by chipping or burning.
Find out more
|
| What's Blooming? Blue False Indigo |
 One perennial I find underutilized is Blue False Indigo, Baptisia australis. This long-lived flower produces 12-inch-tall spikes of blue florets shaped like pea blossoms. Once the blossoms fade, attractive black seedpods follow. Leave the seedpods on for winter interest.
Baptisia forms a big, substantial clump, and its roots do not like to be disturbed after planting. It will grow to 3-4 feet tall by 3-4 feet wide. It will take some time to get established, unlike other perennials, but is worth the wait. Hide its base by planting shorter perennials around it.
It thrives in full sun, but can handle some shade. It is native to our prairies, so it is drought tolerant. This zone 3 hardy plant looks great with columbines, aquilegia spp., and cranesbills, geraniums spp. |
I welcome your feedback on the newsletter. If there are topics you want to learn more about, please email me at nancy.dahl@integra.net.
Sincerely,
Nancy Thorman Dahl, CLP
Cattail Design LLC
Creative Designs for Land and Lakeshore | |
|
|
|
| Money-Saving Tip |
 |
Example of root bound plant
Whether you buy your plants from a garden center or big-box store, buying healthy plants will save you money, labor, and time. Look for these five things when shopping:
- General store surroundings
- Roots
- Overall plant appearance
- Buds
- Pests and diseases
The store's general surroundings can tell you a lot about the care the plants are receiving. If half of the plants are droopy or look bad, head somewhere else.
If roots are coming out of the pot, the plant is pot-bound and the plant will become root-bound when planted. On balled and burlap trees and shrubs, the ball should be solid.
The individual plant should look healthy. Leaves should be green and shiny, not wilting or yellow or brown. It should be full and bushy, and not tall and lanky. Limbs should not be broken. Do not buy trees or shrubs whose trunk or limbs are cracked or overly nicked or scarred.
Look for budding rather than flowering plants. Budding plants transplant easier.
Carefully examine the plant, including under the leaves for pests, diseases or weeds. Avoid plants with abnormal growth called galls.
Don't be tempted to buy something that doesn't look good just because it's the last one or it's on-sale. |
|
|
