“In spring, there are so many blooms in the flower box that trees sometimes get forgotten,” says Donna Danielson, an instructor at The Morton Arboretum’s Plant Clinic. “To give trees their best chance to flourish in spring, give them good care in the fall.”

Tree roots grow well when soil temperatures stay above 40 degrees, and they grow faster in the fall than during the hottest part of the summer. Continue to water mature trees during dry periods until the ground freezes. Water infrequently, slowly and deeply to allow water to soak down at least 12 inches into the soil to be available to the roots.

Fall is also the time to check tree bark and stems for evidence of two major pests:

1. Scrape off any gypsy moth egg masses, which are 1.5-inch long, light-colored, hairy masses. They attach to trunks and branches, are found often on oaks and other trees that lose their leaves in the fall, and usually are within 20 feet of the ground.

2. Once leaves have fallen, check for bagworm cocoons attached to stems. Cocoons are 1.5-inches long and made of dry leaves. Give evergreens extra-close scrutiny.

After the ground is frozen in early- to mid-December, lay a blanket of mulch over the tree and shrub roots. Spread it as far toward the drip line as possible. Shredded and composted fallen leaves make great mulch because they mimic the leaf litter found in forest environments.

“A 3- to 4-inch layer insulates the roots from the frost-thaw cycles in winter and helps retain moisture in the soil during dry periods,” says Danielson.

This article was written by Laurie Casey, a staff writer at The Morton Arboretum; it appeared in the November 14, 2010 issue of The Chicago Tribune.

Note: For more information on winterizing your entire garden, check out this post from fall 2009.

Ed Hedborn, Arboretum botanist and our “Color Scout,” notes that with trees from more than 40 countries around the world something is always turning a fall color at the Arboretum. Members and guests should make repeat visits to enjoy the entire show.

Sugar maples sporting yellows, oranges and reds, maples typically are the big attention-getters, but also beautiful in the fall weeks are lindens, ironwoods, black cherries, hickories and more. Here are some of the lesser-known tree species that visitors can enjoy at the Arboretum:

Pawpaw – These trees, which turn yellow for fall, may seem really out of place. They’re the northernmost member of a tropical family. Their fruits will look like greenish-blue potatoes. When ripe, the fruits can taste like banana custard, although we do not recommend anyone eat these (some people can have an allergic reaction).

Corktree – Not a tree people would see frequently in parks or forest preserves. Nice, thick bark, hence the name “cork” tree. The leaves produce a lovely yellow fall color.

Sumacs – Many varieties in small and large shrubs and small trees. Sumacs are among the first to turn fall color, with many displaying brilliant reds.

Hickories – They sport a beautiful yellow color in the fall. These trees are not so common anymore. Early settlers recognized the hickory wood strength and used these trees to make tool handles, smoke meat, and more.

Beech – This is the tree that brings us beech nuts. It’s a main food source for turkeys, and it’s used to feed the now-extinct passenger pigeons. Leaves turn yellow and brown and look gold from a distance.

Japanese Zelkova – Related to elms, but the Zelkovas do not get Dutch elm disease. They have interesting sawtooth-shaped leaves that turn purple in the fall.

Oaks – You can see many colors from them. Bur oak leaves turn yellow in fall, pin oaks become scarlet red, red oaks turn red, and the Asiatic oaks will become a coppery-brown.

Dawn-redwood – A “living fossil,” this tree wasn’t even know to be a living plant until 1948, when a researcher discovered it in the tree’s native range in China. Dawn-redwood’s fossil record may go back as far as 120 million years. They display a reddish-bronze fall color.

Ginkgo – A botanical oddity. Another “living fossil,” ginkgos are believed to have been in the landscape 200 million years ago. Ginkgos are noted for their fan-shaped leaves and develop beautiful yellow fall color.

Asian maples – The Arboretum boasts many varieties not often seen in parks or forest preserves. These are from Russia, China and elsewhere in Asia. The paperbark maple draws its name from the unique and beautiful bark, featuring a paper-like look with a cinnamon-red color, and its leaves turn red in fall.

Bald-cypress – Often found growing in swampy areas. You almost cannot drown a bald cypress. Unlike other trees that must have drained soil to survive, this tree “breathes” through “knees,” which can grow 4- to 6-feet high. Also, unlike most conifers, this tree is deciduous. Like trees that lose their leaves seasonally, the bald-cypress does not stay green all year long. Fall color is a rich, coppery, reddish-brown.

Freeman maple – A cross between a silver maple and a red maple. This tree gets its adaptability to compacted soil from the silver maple and the lovely form and reddish fall color from the red maple. In the fall, each leaf shows green, yellow, red and purple hues, but the overall look is purple.

Native grasses – In the Schulenberg Prairie, lovely Indian grass, big blue stem and little blue stem are among the showy grasses on display, sometimes 6- to 8-feet tall. Silvery “hairs” on seeds at the grass tips often produce “sparkling highlights” when the sun hits them in just the right way.

But, this is bound to end (we all say) and there will be plenty of chances to do the usual summer garden activities. Here is a helpful and partial run-down of what you should be doing in your summer garden. Our web site has the full list.

* Cool weather and excess moisture in spring allows fungal diseases to thrive. To prevent reinfection, remove as many infected leaves as possible.
* Prune late-spring flowering shrubs and hedges now.
* Avoid pruning oaks and elms between mid-April to mid-July. Oak Wilt and Dutch Ellm Disease are spread by sap-feeding insects carrying the disease from tree to tree.
* Replenish mulch under trees and shrubs to conserve moisture, reduce weeds and control temperature fluctuations in soil.
* Monitor all plants regularly for pest and disease problems.
* Pull weeds before they go to seed. After a rain, roots will pull out more easily and completely.
* Plant summer-flowering bulbs and annuals. Annuals are developing roots; fertilize and keep well watered.
* Monitor container plants (especially those in clay pots) daily for watering needs.
* Pinch garden mums and asters once a month (until July 15) for bushier growth.
* Remove faded blossoms from flowering annuals, perennials, and roses to encourage more blooms.
* Fertilize roses with a 10-10-10 slow-release fertilizer after first bloom.
* Check bird houses for unwanted tenants and fill birdbath regularly.
* Divide and replant iris. Discard any plant showing signs of insect or disease. Iris should be divided every three to five years.
* Remove spent flowers and pinch back leggy foliage from annuals and perennials to promote bushier growth and more flowers. Stop pinching mums after July 10 to allow flower buds to set.

Watch out for anthracnose, which commonly occurs after wet weather. Spores from several kinds of fungi infect newly-grown leaves. Symptoms include brown or black blotchy areas on the leaves. While this will not kill your tree, it is important to discard fallen leaves to prevent re-infection.

“Since fungus needs wet weather to infect, a few things you can do to prevent fungal infections are to avoid overhead watering and if a plant is very dense, you could thin it so it would dry faster after rainfall, ” says Donna Danielson, Arboretum Plant Clinic Assistant.

There are some fungicides on the market, but once a tree is infected, it is too late to spray a fungicide. They should be applied as leaves are emerging.

Some trees are sporting yellowing leaves. A possible culprit is too much soil moisture. This occurs when the roots are not able to dry out in between watering. Too much water can often be more harmful to a tree than not enough water.

As the summer heats up, look out for leaf scorch. “Leaf scorch is a condition and not a cause. The culprits include unfavorable weather conditions such as high winds, drought or soils that are too wet, root damage from compacted soil, grade changes, and restricted root growth,” says Doris Taylor, Arboretum Plant Information Specialist.

Symptoms, usually appearing in July and August, consist of browning on the tips of leaf tips and yellowing between leaf veins and leaf margins.

To minimize leaf scorch, give your tree or plant a break. “Place trees in well-drained soil with adequate root space, water well in dry periods and conserve moisture with a 3-4″ depth of organic mulch,” Taylor says.

For more hot weather advice, Taylor offers the following tips:

While caring for the garden this summer, start thinking ahead to next year. Photograph your yard each month and note where you could use more bulbs or color, or where plants are not staying healthy. This will make it easier in the wintertime when you plan improvements in your garden’s health and beauty.

“My absolute favorite fragrant shrub is viburnum. The aroma is my definition of springtime,” said Jacobson. Try Judd’s viburnum (Virburnum x juddii) or Korean sprice viburnum (Vibrunum carlesii), which both grow about 6- to 8-feet tall and bloom in early spring. Plant in full sun to part shade near a walkway or door where you can enjoy the sweet scent. Later in the growing sesason these shrubs develop deeply-colored red fruit while their leaves turn wine-red in the fall.

Fothergilla sends out fluffy white bottlebrush flowers in April and May before leaves emerge. “Their beautiful flowers are very interesting because they don’t have petals. They are actually clusters of stamens, which are the parts of flowers that hold pollen,” explained Jacobson. Large fothergilla (Fothergilla major) reaches 6 to 10 feet. Or, try  the dwarf variety (Fothergilla gardenii), which is about 3 feet high. Plant in full sun to part shade. Fothergilla has stunning apricot fall color.

Another choice for your home landscape could be one of the low-growing lilac Korean hyrbrids such as “Miss Kim” Manchurian lilac (Syringa patula ‘Miss Kim’) or “Palbin” lilac (Syringa meyeri ‘Palbin’). “Palabin is a very neat, clean shrub that is especially floriferous. It is very dense, so it even looks great in winter,” said Jacobson. Dwarf Korean lilac does best in sun, but can tolerate light shade. It has a lighter fragrance than old-fashioned lilacs and blooms in May and June.

This article adapted from one  written by Arboretum staff writer Laurie Casey that appeared in the May 8, 2011 Chicago Tribune.

Don’t get crabby! Get a new, disease-resistant tree. Many newer crab apple cultivars have excellent or good resistance to common diseases, according to Kunso Kim, Head of Collections and Curator at The Morton Arboretum.

“When you select the right crab apple, it will become a jewel in your landsacpe,” said Kim, who oversees 183 different types of crab apples, one of the largest collections in the nation.

Four diseases seriously affect crab apples:

1. Apple scab damages aesthetics by spotting leaves and fruits and making leaves drop early.

2. Cedar-apple rust blemishes leaves on native cultivars, especially those planted near certain junipers.

3. Powdery mildew is a fungal disease that thrives in wet, humid weather and mars the beauty of leaves and fruot.

4. Fire blight is the most harmful, because this bacterial disease can kill a tree if not treated.

Many disease-resistant crab apples have interesting forms, flowers and fruits. “In fact, I’d say the fruits arte the crab apple’s main feature. They canm last for months, we;; into winter,” said Kim.

Some of his favorites for home landscapes include:

1. Strawberry Parfait crab apple (Malus ‘Strawberry Parfait’)

20′ tall x 25 ‘ wide. Spreading vase shape with pink spring flowers and yellow fall fruits.

2. Tina crab apple (Malus sargentii ‘Tina’)

5′ tall x 6′ wide. Shrub with white flowers and red fruits.

3. Molazam crab apple (Malus ‘Molten Lava’)

12′ tall x 15′ wide. Broad, weeping form with white flowers and orange-red fruits.

4. Donald Wyman crab apple (Malus ‘Donald Wyman’)

20′tall x 20′ wide. An old-time favorite with white flowers and red fruits that remain through winter.

This article was written by Arboretum staff writer Laurie Casey and appeared in the May 1, 2011 issue of The Chicago Tribune.

To honor Earth Day and Arbor Week, Tree Talk and The Morton Arboretum have introduced a new section accessible from the home page of Tree Talk that will feature your special or notable trees. Your tree may not be a record-breaker, but it is special to you in some way. And we’re inviting you to share the story of your special tree with the Tree Talk community.

This venture is a direct result of the Tree Census program launched by the Arboretum and in 2010. When our research teams were in the field throughout Chicagoland, they met so many people who wanted to share their own tree stories. The new “Tree Stories” section is the result.

As a member of the Tree Talk community, you can submit your own special tree story and a photo to share the importance of trees to you and your family.

April 4 – Always make pruning cuts on an angle. That way, water is more likely to run off instead of collecting on the cut area and causing rot or disease. A slanted cut also drys out faster after a rain. Finally, the slanted cut leaves a smaller stub, which is better for the plant’s appearance.

April 5 – Evaluate the shape of your needled evergreens. If there are branches jutting out at odd angles, early spring is a good time to get rid of them. But don’t just shorten them as much as needed or you’ll be left looking at an ugly stub. Instead, prune down low, within the plant, and no one will be the wiser!

April 6 – Clear out the lawn, flowerbeds and vegetable garden before you get too busy and before plant growth covers everything. Get rid of rocks that may have risen to the soil surface during the winter months and rake out gravel and sand that might have been shoveled or pushed in.

April 7 – Thinking about moving a shrub or small tree to a new location? Early spring is a great time to do this – but while the plant is still dormant so there will be less trauma. Then, when it does start growing, it can direct all its energy into a great show. Always be sure the soil is workable before undertaing this type of project.

April 8 – Get in the habit of forming a basin around every plant you install or move around the perimeter of the plant’s drip line. Mound up the soil by a few inches in a circle around the plant’s root zone. Then, when you water, it will go straight to the roots. A basin also holds mulch well.

April 9 – Make a “nursery” area in a sheltered part of your yard. Clear it out, define its boundaries with a low fence or some rocks and put in some organic matter. You can temporarily plant, or “heel in,” bare-root shrubs, trees and rosebushes until they are ready to go into their permanent homes.

April 10 – Are deer an ongoing problem? Their destructive dining can be even more frustrating at this time of year when they go after young, emerging plants or ones you’ve just planted. Various repellants can work, but deer can be relentless and, if you mean business, you will need an 8-foot-tall fence around your garden.

We are very pleased to announce that the new Integrated Plants Database of The Morton Arboretum is up and running, just in time for the field season. This system provides integrated access to data on the plants of the Arboretum’s living collections and herbarium, as well as specimen-level links to the Arboretum’s outstanding interactive collections map, scanned herbarium sheets, and – for a few species – photographs of living plants. The system is mounted online and usable by anyone in the world. This dataset encompasses more than 222,000 live plants representing nearly 4,300 taxa and nearly 60,000 database herbarium specimens.

What can you do with this database?

You may already have plenty of ideas of what you’d like to do with this database, but in case you need a few suggestions, try these:

1. Figure out where to find a particular species on the grounds. From any page on the database, you can use the quick-search box to search the system by common name or scientific name, or by a particular living collection. For example, you could look for all plants in the Ozark collection. From the advanced search page, you can search by a particular collector or collector year. Once you find an accession you would like to find, you can click links to map each plant in the accession!

2. Get a quick idea of what plants look like. Many herbarium specimens have been scanned and are available online. When you do a search, look at the camera icon next to any herbarium specimens: Those icons link to scans of the herbarium specimen, and these are a great way to start to sort through a plant identification or selection problem. Also, in the future, we’ll be adding photos of live plants. At this point, only white oak has live plant photos associated with it, but watch for more during the coming year.

3. Figure out when plants flower. The herbarium specimens have been coded by presence of flowers, fruits, buds and vegetation. From the advanced search, you can select “Herbarium” as your collection and “Flower” from the source information. Just the other night I was wondering what the range of flowering dates was for Betulaceae in our area. Click here to see what a search looks like.

4. Study the distribution of plants. Many of our scientific names have ranges coded so that you can see roughly what their range is. Many have USDA hardiness zones coded as well. For wild-collected material (both living collections and herbarium), you can look at collection site data, including coordinate data that you can map in any mapping application like Google maps. For example, you might want to find out what sites were visited by recent NACPEC expeditions to China, or where Hill’s oak has been collected in the region.

Look for more information in a special article to be published in the “Our Impact” section of the summer issue of SEASONS magazine – due to arrive in member homes or available online at the end of May.

And, let us know what you think. Enjoy!

Andrew L. Hipp, PhD
Plant Systematist and Herbarium Curator

Saturday, April 9, 2011

The season is brimming with hope and expectations as spring emerges in the garden. Whether you are landscaping a newly built home or improving an existing landscape are you satisfied with how your garden looks during each season? Is there curb appeal? Inviting places to sit and relax? Or is there an eyesore or view you would like to screen?

Picking the right plants or deciding where they should go can be intimidating. Let us help get you started on a plan or solve that problem area.

Sign up for a 20-minute garden design consultation with Arboretum Plant Clinic landscape designers and master gardeners. Bring photos and sketches. Watch our 10-minute “Planting Design” presentation while you wait, and take home information on how to get more landscape design and garden care help. You will walk away with immediate planting plans and ideas for your landscape.

Register today or call the Registrar’s Office at 630.719.2468
♦ DH925 Saturday, April 9
Administration Center. $15 (non-members $22)
9 am – noon