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Time for fall clean-up. Remove weeds before they go to seed. Cut back perennials unless they have winter interest.
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Take cuttings of annuals such as coleus, geraniums and impatiens to enjoy indoors in winter. Save seeds of species flowers and veggies.
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Order spring blooming bulbs to plant now.
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Cleanup & discard dead leaves from roses; when flowers are spent. Cut back hybrid tea canes to 24-36' and remove diseased areas of canes.
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Apply mulch if needed after the soil freezes to keep soil temp constant and prevent heaving.
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Move or divide crowded perennials-have a plant swap with friends!
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Cold frames will extend growing season of veggies such as radishes and lettuce. Close top at night and vent during the day.
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Clean windows before bringing houseplants inside, to increase light for the plants. Quick temperature changes can result in yellowed foliage and leaf drop; bring plants indoors before temperatures dip below 55°F.
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Check for insect pests and treat before you move the plants inside.
Perennial Weeds in the Lawn and Landscape
Bugs come and bugs go but weeds are always with us. Ask any gardener and they'll tell you that they spend more time and effort managing weeds than insects and diseases combined. So, let's take a look and this class of pests and pay special attention to one group of weeds, the perennials, since late summer and early fall is a good time to control them.
Just as we classify our favorite desirable plants by their life cycle (annual, biennial and perennial), weed scientists do the same for weeds. Perennials, of course, are plants that survive more than two years with the help of some kind of vegetative survival structure….roots, rhizomes, stolons, bulbs, tubers or woody stems. Ok, let's get specific…dandelion has a taproot, Canada thistle and quackgrass have rhizomes, ground ivy has stolons, wild garlic has bulbs, yellow nutsedge has tubers and poison ivy has woody stems. Have we named some plants you are familiar with? Hey, we've even got kudzu in northern Bucks County.
The reason these weeds are so persistent is that we can pull, cut and mow these plants and they seem to survive anyway. The energy they store in those survival structures allows them to re-grow if we are not persistent. Frequent mowing or pulling will do the job…if you do it frequently enough and if you keep it up over several years. But many weeds such as yellow nutsedge, ground ivy and dandelion tolerate mowing and pulling, either because they hug the ground or they simply re-grow fast enough that they recharge themselves quickly. Most perennials will easily grow through organic mulches and some will grow through plastic weed barriers. And just to keep you on your toes, most of these perennials also produce plenty of seeds.
What's a gardener to do? Herbicides are chemicals that control weeds. Herbicides that move within the weeds (translocate) are especially effective on perennial weeds because they move throughout the plant, even to underground parts, and disrupt plant functions. Roundup is the trade name for an herbicide that contains an active ingredient called glyphosate. There are many other trade names for this active ingredient so feel free to shop for a "generic" brand if you choose to use it. Glyphosate, when applied properly, will control almost all perennial weeds. Here are the key points to keep in mind when using glyphosate products.
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the better the weed is growing, the better the herbicide will work. In order for the active ingredient to get to underground parts the weed has to be actively growing and, importantly, moving energy (sugars produced by photosynthesis) to those parts. The herbicide moves with the sugars. That is why late summer and fall applications are better than spring and early summer applications for most weeds. This is also why you should not mow, cut, till or otherwise disturb the weed you want to kill prior to glyphosate application. You might think you are giving the weed a double whammy by injuring it first…but that ain't so.
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glyphosate is only absorbed by plant foliage; there is no root uptake. So, apply to foliage only.
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glyphosate is "non-selective". That means any plants that are contacted by it will be injured. Do not allow drift of glyphosate to contact the foliage or thin stems of desirable plants. It is hard to 'spot treat' weeds in many situations without getting drift. Several tricks can be used to eliminate drift, such as wiper applications.
There are some selective, translocated herbicides. The products commonly sold for dandelion, clover and other broadleaved weed control in home lawns (2,4-D, MCPP, dicamba, triclopyr) are selective; they kill broadleaved weeds without injuring the lawn grasses. A very nifty characteristic….selectivity. Some of these ingredients are also sold to control nasty weeds in places other than the lawn. Poison ivy, multiflora rose and other woody weeds come to mind. Triclopyr is a relatively new ingredient that is very effective on this type of weed and is readily available in garden centers.
Although most folks think of spring as the time to control lawn weeds, the perennials are best treated in September and October. The herbicides work better and the lawn can quickly fill in the voids left by dying weeds since the cool-season grasses that make up our lawns continue to grow, even past frost. The best defense against lawn weeds is dense turf so be sure to fertilize this fall, too. Some of you are probably thinking 'weed and feed'. It's OK, but sprayed on applications of broadleaved weed control products work better, especially if you have a tough customer such as ground ivy or wild violet. In fact, weeds such as these probably require two applications about two weeks apart in the fall.
As fall approaches, our contest with annual weeds such as crabgrass, pigweed and foxtails is about over. Whether you are winning or losing, the game is up in early October when Mother Nature drops the frost bomb on them. They'll be back next year from seed. Now is the time to take a whack at the perennials. If you do, their chances of being troublesome next year are minimized.
The Master Gardeners of Bucks County will be offering Fall Gardening Seminars; $3 fee for each seminar. Seminars will be held in the meeting room at Neshaminy Manor Center, Doylestown from 7:00-8:30 PM. Call 215-345-3283 to register.
September 26 Bonnie Olliver will demonstrate how to divide perennials, save seeds and force bulbs for indoor pleasure.
October 17 Learn more about controlling weeds, Scott Guiser, Extension Educator will show you the Wacky, Wicked World of Weeds.
If you haven't come to the Extension office this year, the Demonstration gardens out front are open for viewing 24 hours a day every day and brochures are available in the Boxes to list and describe the plants. The Gardener Selects demonstration garden is at it's peak right now. A few of our favorites this year are Euphorbia 'Diamond Frost', Calibrachoa 'Mini Famous Lemon', Celosia 'Fresh Look Red' and Diascia 'Whisper Pumpkin'. These plants, along with the rest of the Gardener Selects entries, are being evaluated by MGs across Pennsylvania. From these evaluations, Penn State will pick the "Plant of the Year".
Sure, you've heard this "marketing" phrase, but did you know that it's true? Fall is an excellent time to plant. The cooler temperatures and shorter days send a message for the plant foliage to stop actively growing. This combined with adequate rainfall allow the plant to grow a good root system and become established before the next active growing season. You should try to get perennials in the ground by the end of September to mid-October to allow sufficient time for the roots to "dig in" before the ground freezes. Otherwise the small root ball may "heave" and desiccate over winter. Shrubs and trees can be planted until Thanksgiving most years. Be sure your newly planted perennials, trees and shrubs receive adequate moisture; 1 inch of water per week by rain or hand watering, until the ground freezes. If the winter is dry, water the plants again during "thaws".
Fall is also an excellent time to find bargains at local nurseries, most nurseries have great sales in the early fall. Perennials that look tired and worn in the pot often spring back to life once they are in the ground. There are also often great bargains on Spring blooming bulbs . Order your spring bulbs now for fall planting.
Nutsedge - Our lawn was mowed yesterday. What's the grass that's already taller than the lawn?? Yellow nutsedge (not a grass) has yellow green shiny leaves and erect stems. The tops and stems die in winter, but new growth occurs in spring from underground rhizomes and nutlets. MANAGE is a product that affects nutsedge. Make sure you read the label before using any herbicide.
Bagworms - Bagworms are quite noticeable now since their cases are brown against the green ornamentals on which they feed. These insect pests attack evergreens such as junipers, arborvitae, spruce and pine as well as some deciduous trees. Their cases or "bags", sometimes mistaken for cones since they are brown and conical in shape. Bagworms eggs overwinter within the bags that were inhabited by female bagworms. Bags may contain 500 to 1,000 eggs. Do not treat with insecticides now, it is too late. Hand pick what you can reach, discard the cases and plan a mid-June spray for 2007. Bt works on young bagworms. Sevin or pyrethroids are excellent too.
Scott
Guiser, Extension Educator/Horticulture
and
Sue Schneck, Master Gardener Coordinator
This page last updated Thursday, February 22, 2007
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