Monthly Gardening Calendar
Sharon Morrisey, Home Horticulture Agent
Milwaukee County University of Wisconsin-Extension

Water, water everywhere. Saturated soil and wet leaves have led to root rot and leafspot problems. Thin out mulch around herbaceous perennials like irises and peonies. Prune lightly to thin out plants with dense foliage where moisture is slow to evaporate. Wet leaves are more susceptible to fungal leafspots. Expect apple and crabapple to loose leaves early due to apple scab leafspot. Rust and anthracnose leafspots are appearing on many other plants. Rake up and destroy these leaves often to reduce the spread next year.

Seeds that have not germinated in the wet, cold soil will need to be replanted. You might be just now getting into your garden. Don't give up because there are a dozen or more crops that can be sown from seed or transplanted in mid-July for harvest yet this fall (see calendar entries).

You can help the hungry in your community by sharing your garden's harvest through the "Harvest for the Hungry" program. Take your excess produce to your local food pantry or one of the fifteen local garden centers and nurseries that are serving as drop-off sites. Or call Second Harvest Food Bank at 414-931-7400 to determine a location near your home. "Harvest for the Hungry" is a local program which supports the national "Plant a Row for the Hungry" program of the Garden Writers Association of America.

2000 Official Drop-Off Sites for "Harvest for the Hungry"

Bluemel's Floral & Garden Center 
Greenfield 414-282-4220 

Hawks Nursery 
Wauwatosa 414-258-5525 

Luxembourg Gardens 
Franklin 414-425-5696

Milaeger's, Inc. 
2 locations in Racine
262-639-2040 262-886-2117 

Nature's Nook
New Berlin 262-786-3700
Franklin 414-761-8300

Shady Lane Greenhouses
Menomonee Falls 262-251-1660

Yerke Greenhouse
Mukwonago 262-363-8911

Again in this month's calendar, the UWEX Infosource documents are available for further discussion on a topic.  Just follow the link under the paragraph of that topic.

For more local gardening information and links to many other great gardening websites, visit the UW-Extension Hort Team site at http://www.uwex.edu/ces/wihort .

First Week

Be vigilant in watching the leaves of your tomato plants for signs of leaf spot diseases. The most common, septoria and early blight, appear first on lower leaves and can be effectively controlled if leaves are removed as soon as leaf spots are seen. If it has gotten away from you, chemical control is also possible with a fungicide containing chlorothalonil. 

To prevent bacterial wilt of squashes, melons, cucumbers, and gourds, apply rotenone, carbaryl or methoxychlor as a dust if either striped or spotted cucumber beetles are present. Dust late in the day after flowers have closed and bees are no longer active. Plants already infected with the wilt should be removed and destroyed immediately.
 

Squash vine borer is a difficult to control pest of vine crops, particularly summer squashes. Adults lay eggs for a three week period starting in late June. Cover lower section of stems with floating row cover or even aluminum foil to prevent egg laying. Look for and remove by hand any brown egg masses seen on the lower stems. Spraying carbaryl (Sevin) is more effective than using the dust formulation. If entrance holes and "sawdust" are seen, a wire can be inserted and threaded through the stem for some distance to kill developing larvae inside. Or slit stems lengthwise to find and destroy the caterpillar inside. Then bury slit stem section under some soil.

Renovate June-bearing strawberry plantings immediately after harvest. Control any weeds that have invaded and then mow over the top with the mower set high enough not to damage the crowns. Eliminate new plants between the rows by cultivating. Then sidedress with a 10-10-10 fertilizer. Lightly work it into the soil and water in.

Pinch back garden chrysanthemums one last time. Flower buds will form on new growth and be ready for fall display.

No further pruning should be done on trees or shrubs since the new growth this stimulates will not mature sufficiently before the cold days of winter are again upon us.

Likewise, woody plants should not be fertilized again until leaves begin to color and drop this fall. Fertilizing, like pruning, stimulates new growth.

Garden flowers, whether annuals or perennials, benefit from "deadheading" after flowering. By removing the spent flower heads, energy is used to produce more flowers or foliage and roots.

In general, flowering requires lots of energy so it can be quite helpful to fertilize flowering herbaceous plants once flowering begins. Fertilize once again before the end of the season.

Prevent peach tree borers on plum, cherry, apricot and peach by painting or spraying the trunks and lower limbs with chlorpyrifos. Follow label directions exactly.

Second Week

Watch for cabbage worm, corn borers, cutworms, potato leafhoppers, aphids, tarnished plantbugs, and thrips on many vegetable crops. Obtain a copy of UW-Extension publication A2088 to help you manage insects in the home vegetable garden. In Milwaukee County, call 290-2400 for ordering information.

Keep cole crops and potatoes covered with floating row cover to exclude cabbage worm and leafhoppers.
    

Seeds can continue to be sown throughout July for late crops of beets, bush beans, carrots, chard, Chinese cabbage, cucumbers, kohlrabi, and corn.

Transplants of broccoli, cabbage, cauliflower, Chinese Cabbage, collards, kale, kohlrabi, onion sets, and onion plants can be planted for fall crops.

Keep tomato plants well mulched and evenly moist to reduce the incidence of blossom end rot and cracking.

Oak, elm, ash, and maples infected with one of the wilt diseases will begin to show typical symptoms as the summer heats up. Bring samples of branches that have recently wilted to the Plant Doctor clinics at Boerner Botanical Gardens. UW-Extension staff are there from 2:00 to 6:00 on Tuesdays. From 10:00 to 12:00 on Saturdays other local horticulturists are on duty to answer your questions.   

Begin looking for webs of fall webworm on woody plants. Control by cutting out branches wrapped in webbing where possible. Spraying with the botanical insecticide B.t. (Dipel, Thuricide, and others) is only very effective on young larvae.

Third Week

The final preventative spray of chlorpyrifos should be applied to the trunk and lower limbs of white-barked birches susceptible to bronze birch borer. Annual treatment includes two additional sprays on May 20 and June 15. Trees weakened by attacks of leafminer are more at risk for bronze birch borer.(823 & 822)  

Allow asparagus to produce tops now. Fertilize the plantings with 10-10-10 fertilizer.

Summer raspberries should be coming in well now. Watch plantings closely for the many possible insect and disease problems. Harvest fruit often and thoroughly to reduce the number of picnic bugs competing with you for fruit. Viruses cause plants to be stunted and discolored, and fruits to crumble easily. See UW-Extension publication A1610 for pest descriptions and controls.
 

Ornamental kale, grown for its colorful foliage should be transplanted in mid-July. When planted earlier, this cole family member tends to bolt causing misshapen, cone-shaped plants.

Watch for yellowing and wilted leaves on cole crops such as broccoli, cauliflower, and cabbage. This may indicate black rot or club root, two serious diseases of these crops.

Divide iris plantings every 3 - 5 years to renovate plantings and clean-out borer infested plants.
 

Fourth Week

Alpine currant shrubs infected with the anthracnose fungus will lose leaves and sometimes completely defoliate by mid-summer. Fallen leaves will be spotted with the fungus and should be diligently removed and destroyed to reduce the infection next year.

Honeysuckles susceptible to the common leaffolding aphid should be sprayed every 10 - 14 days with insecticidal soap. Pruning out infected stems every fall will reduce the population considerably but the prevalence of the insect means that others will probably fly in again. Since many species of honeysuckle are invasive especially in our natural areas, it might be best to consider replacing them with something else.