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.

With properly sharpened tools, (hand-held pruners, loppers and pruning saws), and the right techniques, even novice “prunophobics” can tackle this job. Make a slanted cut (to prevent standing water on the stub) at or near the closest “vee” in the branch – to avoid creating a big stub. Cut close, but not too close, to the remaining limb; you don’t want to injure the branch that’s left. Disinfect your tools (with a bleach solution) if removing a diseased branch. For more information on proper cuts and specific techniques click here.

Of course, if you’re a “prunaholic” who can’t stop snipping, Doris Taylor, Arboretum Plant Clinic Manager, advises, “Go slowly because you can’t put it back on!” After each cut, step back and look at your work from all angles to see if you’re creating a pleasing shape.

The most common mistakes people make in pruning are “forsythia meatballs” and “buckthorn babies. ” The meatball look, attained by pruning a shrub such as forsythia into an unnatural shape, can also result in a loss of blooms. At the other extreme, gardeners sometimes go to great pains to preserve parts of a tree without realizing it’s a volunteer weed. “Look carefully at the leaves and bark of the stems,” Taylor cautions. “Often invasive plants like buckthorn will grow up right in the middle of your plant. There’s no need to save those!”

This post was adapted from an article written for the Chicago Sun-Times.

Ask Us
Q: My lilac is very overgrown. Should I prune it now?
A: Typically, spring-blooming trees and shrubs are pruned after they bloom so that you can enjoy the flowers. It will not hurt if you prune a plant before it flowers, and sometimes you may need to forfeit the flowers if the plant’s health is at stake.

Q: Is this true that tree paints are no longer necessary?
A: Research concluded that wound dressings did not affect the rate of preventing disease. In most cases, pruning cuts will close by a natural callus without any aid. The exception would be pruning oaks and elms in the summer. The potential for spreading oak wilt and Dutch elm disease are greater when insects are active.

Q: Last year I pruned a broken maple branch in early March and the sap ran for three weeks. Is there something I should have done?
A: Maple, birch, elm, walnut and a few other trees are considered “bleeders.” This is unsightly but harmless. To avoid the “hemorrhage,” don’t prune these trees until the foliage has emerged in late spring.

“When high winds rip large limbs off a tree, it’s much better to have a clean cut than to leave a jagged edge,” says Plant Information Specialist Doris Taylor of the Arboretum’s Plant Clinic, which diagnoses tree and other plant problems and recommends solutions.

Damaged trees attempt to isolate their “wounded” areas, growing a “wall” of cells to block any possible tree rot from infiltrating the trunk. However, when a “wound” is jagged, the “wall” could be compromised, leaving the tree vulnerable to diseases or pests, Taylor says. To cure the problem, the Arboretum recommends a three-step pruning technique.

Step One: Cut to remove most of the damaged branch, to reduce the weight pulling on the trunk.

Step Two: Make a cut beneath the remaining damaged branch, approximately one-third of the way up through the branch. Make this cut between the edge and the “branch collar,” a swollen area where the branch arises from the trunk.

Step Three: Make a final cut entirely through the branch, just beyond the branch collar. Never cut flush with the trunk, which would cause a very large wound and make it difficult for the tree to heal. In contrast, trees that receive a clean cut develop a hard edge, like a callous, which is a sign that the tree has healed. Hanging branches are hazards to people or property, and should be pruned as soon as practical.

Taylor emphasizes that some jobs are dangerous for average homeowners, who never should climb a ladder to prune a tree, and especially not with a chain saw. Similarly, if a tree is blown over or the trunk is so severely damaged that the tree may fall, safety is a primary concern. Homeowners should call a certified arborist to handle these cases.

Such arborists can often save young or small trees – up to about 15 feet tall – that are partially blown over. When a tree is destroyed and a homeowner wishes to plant a new tree in the same spot, Taylor advises that you engage an arborist to remove the old stump.

In choosing a replacement tree, select a species that is suitable for our area and that would help diversify the landscape. Consult The Morton Arboretum Plant Clinic for free assistance, at 630-719-2424 or plantclinic@mortonarb.org.

A diverse landscape helps promote a healthy ecosystem and guards against extensive landscape damage when exotic diseases or pests strike. Lightening sometimes kills a tree outright, and other times causes no damage. It sometimes takes a year or two for death to occur. After lightning strikes, prune the tree for safety otherwise wait until the following growing season to assess damage. Keep tree well watered and fertilized, according to Taylor.

Source: Morton Arboretum press release, August 2007.