Add/Update an Event
Find Events
FAQ
Home < Almanac < Gardening
Attractions | Almanac | Local Information | Wisconsin | Store | Lodging | Maps | Weather

More Wisconsin
Almanac

Almanac Home Page

Crop Weather Report
  
weekly

Gardening in Wisconsin
  
monthly

Night Sky
  
periodic

Outdoor Report
  
weekly

 

Wisconsin Yard and Garden Tips

September, 2016

Plant Hardiness Zones Map | Last Spring Frost Map | First Fall Frost Map
UW Extension County Offices
By Sharon Morrisey, Consumer Horticulture Agent, Milwaukee County UW-Extension
Wisconsin Yard and Garden Tips is updated monthly by Milwaukee County UW-Extension. Applicability in northern Wisconsin counties may be delayed one to two weeks in spring, and advanced a like period in fall.

This summer has gone from simmering to sweltering and everything in between. Sunscald and stress and spider mites were the results. However, field crops are a couple of weeks ahead of schedule statewide.

The days shorten quickly approaching the autumnal equinox on the 22nd. By the end of the month, most of the state will have seen night temperatures in the 30ís. The shorter days and cooler nights signal plants to prepare for dormancy. They send carbohydrates down into their roots for storage. What we notice are the leaves changing for a quick flash of color before they fall.

The changing conditions make September a good time to perform some important gardening chores. Grass seed sown now through the middle of the month will germinate quickly in the warm soil and growth strong and stout in the cool air. Plants planted or transplanted now root well so it is a good time to plant new trees and shrubs or dig and divide some perennials. Since lawn grass recovers in the fall, now is a good time to core aerate or dethatch if your lawn needs it. Conditions are also great for using broadleaf herbicides to control lawn and garden weeds.

Start looking for UW-Extension horticulture resources through the Wisconsin Horticulture website (http://hort.uwex.edu ). The search box lets you search for publications and factsheets. The link to the diagnostic labs take you to insect and disease information. Ask the Expert allows you to submit a question for a response by e-mail from someone in your region of the state.

First Week

From August 15th until September 20th is the best time to establish a lawn in Wisconsin either from seed or sod. Both require a good seedbed and even moisture. Step-by-step instructions are given in UWEX publication A3434 from http://learningstore.uwex.edu .

If you fertilize your lawn three times a year, it is time for the September application. Wait until the third week or so if you wish to use a combination weed and feed product to control broadleaf weeds at the same time you fertilize. If you are using fertilizer without the weed killer, apply it to dry grass and then water to wash it off the grass blades or apply it just before it rains. If applying a weed and feed product, water thoroughly before or apply it when the grass is already wet from dew or rain. Split the application in half and spread each half over the entire lawn in two different directions to avoid streaking.

Leaf lettuce, chard, spinach and radishes can still be planted for harvest yet this fall.

Watch beans for holes in the leaves caused by the second generation of the bean leaf beetle. At first sign of feeding, organic gardeners can use neem or spinosid for control. Carbaryl and permethrin are synthetic insecticide options.

Take cuttings of shade-loving flowering annuals and tender herbs to grow on a sunny window or under lights indoors this winter. Good candidates for this include wax begonias, impatiens, coleus, lantanas, and fuchsias. Geraniums need a lot of light but can survive indoors well enough to be grown outdoors again next year. Parsley, sage, rosemary, basil, oregano, and thyme can be grown indoors, too.

Houseplants that have been "vacationing" in the backyard this summer should be brought in soon. Give them a good blast of water all over before bringing them in to help remove freeloading insects. Insects in the soil are probably not damaging but more of a nuisance when brought indoors. For the first couple of weeks after the move either be prepared to kill them one at a time or help them migrate back outdoors. Replacing the potting soil before bringing plants indoors is another option..

Thanksgiving and Christmas cactus can be left outside a little longer to expose them to cooler night temperatures. Start letting them dry out more between waterings. This plus the cooler nights will stimulate blossom production.

Cyclamen that dried down in spring and were repotted in mid-summer are ready now for more moisture and cooler temperatures to begin flowering.

Place amaryllis in storage for a 2 month rest before starting the reflowering process. Select a cool (40 - 50 degree) spot and stop all watering. Plan to begin watering again 9 - 12 weeks before you want it to flower.

Second Week

A vigorously growing lawn is the best pest preventative strategy against weeds and diseases. If you have a thatch layer of more than 1/2", dethatching or core aerating is recommended. When looking at a slice of your lawn in cross-section, thatch looks like a cocoa doormat of dead, fibrous material between the green leaves and the soil and roots. Dethatching machines use vertical blades to rip out thatch while core aerators make holes which allow air and moisture to penetrate into the rootzone. Loosened thatch should be raked and removed (or composted) but the plugs of sod and soil brought up by aerating should be left on the lawn. This allows soil microbes to breakdown the thatch layer from the top down. Core aerating has the added advantage of simultaneously improving heavy clay soils. It can also help smooth out bumpy lawns blessed with healthy earthworm populations.

Buy colorful, hardy flowering mum plants now for transplanting into beds where annual flowers will soon be removed. Some of these hardy garden mums need mounding with soil after the foliage has died. Add two inches of mulch after the ground has frozen to protect them through the winter. In future years, divide large clumps in spring.

Third Week

Broadleaf weed killers are even more effective now than in the spring so this is a good time to control dandelions, creeping Charlie, clover, violets, etc. Either spot treat with liquid herbicide formulations or apply weed and feed products.

Fall leaf season is not really upon us yet but it is important to the control of many fungal and bacterial leaf spot diseases that fallen leaves are raked and removed. Leaves from disease-free plants can be managed without collection and removal or burning if you chop them up with the lawn mower. By mowing more often or going over areas with a lot of leaves several times, you can simply "leave 'em be".

Radishes can still be planted and harvested this fall.

Many fibrous rooted perennials should be transplanted every 3 - 5 years as a general rule. Fall is the time to divide and transplant plants that flower in the spring while fall flowering ones like chrysanthemums should be done in the spring. Cut back tops to 4 - 6" to reduce transplant stress. Thoroughly prepare the new planting site. Plan to mulch first year transplants well around Thanksgiving to protect even the normally hardy species.

Pumpkins, summer squashes, and gourds to be stored should be harvested before the first frost. Pumpkins that have begun showing color will continue to ripen after harvest. Use great care not to nick the rind during harvest since this will lead to more rapid deterioration.

Fourth Week

Apple varieties are showing up at fresh markets and roadside stands. Seek out some new varieties to eat fresh or create delicious desserts with. Apple trees can be planted now, too. Select disease resistant ones such as Redfree, Prima, Priscilla, Jonafree, Nova Easygro, and Liberty.

After frost has browned the foliage of non-hardy summer flowering plants such as canna, dahlia, gladiolus, caladium, and tuberous begonia they should be dug and prepared for storage. All should be air dried before placing in a cool spot for the winter. Gladiolus are stored dry and uncovered while all others should be covered with well wrung-out peat, soil, or sand to keep them lightly moist.

Fall is a good time to transplant woody landscape plants that are either container grown or balled and burlapped. Dig the hole 4 - 5 times wider than the plant's rootball. Many plants are sensitive to being planted any deeper than they were growing originally so try not to dig the hole any deeper than the ball so that settling does not occur after planting. Use the same soil to backfill without adding organic matter or fertilizer. Mulch the area over the roots and stake trees securely.

Keep harvesting second plantings of the cool season vegetables including radishes, lettuce, Chinese cabbage, chard, spinach, broccoli, and the other cole crops. Some such as parsnips, peas, Brussels sprouts, and kale actually have enhanced flavor after a frost.


For more information, contact Home Horticulture Agent Sharon Morrisey.

Plant Hardiness Zones Map | Last Spring Frost Map | First Fall Frost Map | UW Extension County Offices

Press - Ctrl D - to save this page

Search for anything at Wisconsin Online!

Copyright © 1995-2016 All About Wisconsin, Inc. All rights reserved.
Wisconline, Wisconsin Online, and Wisconsin.Info are registered trademarks of All About Wisconsin, Inc.

Home | About Us | FAQ | Advertising | Comments | E-mail Us | Add/Update an Event