View Full Version : Over-seeding after using Weed-N-Feed

Davis TLC
01-18-2000, 11:04 AM
I have a customer who wanted to have lawn over-seeded last fall, but used weed-n-feed. Has anyone had any problems overseeding in the spring after a fall application of weed-n-feed. Would appreciate your comments.<p>----------<br>Richard <br>Davis Total Lawn Care

01-18-2000, 02:24 PM
reseeding in the spring would be no problem. i ussually wate only a couple weeks after puttin a weed and feed down before i seed and have had much success. especially since by time spring comes it would have been like 5 months since it was applied.

01-18-2000, 02:27 PM
There will be no problem overseeding in the spring.That chemical will be long gone.<br>You should usually be able to seed 2 to 3 weeks after the application.<br>But if your going to seed i wouldnt put down a pre-m this spring

01-18-2000, 02:31 PM
The lawn will be fine for overseeding in the spring. The weed component of the fertilizer is gone. (Unless it is a pre-emergent with an ultra long residual)<p>The thing to watch for if you are overseeding is the use of pre-emergent herbicides in the spring. (These are used to kill grasses like crabgrass & others). If you use these prior to seeding, the new seeds will fail. Dont use any weed control on the overseeded area until the seedlings are mature.<p>I try to get my customers off of the store bought &quot;weed & feed&quot;. I think it's garbage.

Tony S
01-18-2000, 06:54 PM
What would you recomend rather than store bought weed & feed?

Kent Lawns
01-18-2000, 06:59 PM
Store bought weed & feed really is garbage. Milorganite is particularly crappy.

01-18-2000, 08:09 PM
The chemical used in most Weed & Feed fertilizers is just a herbicide called 2-4D. This is the herbicide that ALL fertilizer application business' use to control weeds in peoples lawns. I highly doubt that this herbicide would prevent the newly planted seed from germinating. You may be thinking of a pre-emergent type fertilizer or weed preventer. If a lawn is treated with ANY type of weed block...then no seed will germinate. Applying a herbicide like 2-4d won't do any harm to the new seed.

01-19-2000, 04:46 AM
Goodbuddies:<p>That is not necessarily true information. :)<p>1.) Not all lawn care's use 2,4D herbicide. Most do, but many companies, myself included have a 2,4D free option. Confront herbicide, for example is popular and contains no 2,4D. TruGreen makes some applications with MCPP & dicamba only.<p>2.) 2,4D application decreases grass plant metabolism and can be harmful to new seedlings. The rule of thumb is no weed control until after the 3rd mowing.

01-19-2000, 04:51 AM
Weed & feed, 2-4,D, or any other herbicide: READ THE LABEL, READ THE LABEL, AND READ THE LABEL AGAIN!! Label is a legal document, and use of product outside label directions is illegal.<br>Generalization: postemergent herbicides usually warn not to treat area 2 to 3 weeks before seeding, and not to treat emerged seedlings until after 2nd or 3rd mowing.<br>Another generalization: most preemergents will not allow seed germination for 4 to 8 months (depends on A.I.) On new spring seeding use siduron as preemergent. It will control crabgrass and allow grass germination. Downside is the cost and need to repeat in 30 days.<p>----------<br>Jim<br>South Bend, IN

01-19-2000, 07:29 AM
I have never seen a pre-m last more than 2 months.Unless you do more then one app.The barrier brakes down pretty fast with traffic and the weather

01-19-2000, 08:16 AM
Preemergents and most other chemicals applied to lawns are broken down by microbal activity (by far the largest activity), photodegradation and other natural events. Traffic and weather may reduce the health of the turf so weed germination is enhanced. No premerg is 100%, the best are around 95%. So when one crabgrass plant puts out 12,000 to 15,000 seeds, some of which are viable for up to 15 years, one crabgrass plant last year equals 600-750 crabgrass plants over the next 10-15 yrs, even with preemergents.<br>Again, are you applying according to the label? Really? Label can tell you what setting to use, but is it right? Couple of years ago I tried to help a buddy calibrate a Lesco spreader. We could not get away from almost a double dose of chemical about 2 feet right of center. Few months later a golf magazine ran an article on the same thing. Last spring Lesco came out with a change in gearing to supposedly correct problem. My buddy got the retro kit, but we never took time to see if it really works. I have used Spykers for years, and he has converted to them.<br>Another example of calibration: I had calibrated spreader for Team years ago, and decided to check my settings 3 yrs ago. Wow- the settings I was using wound up: 1/3 of product to left side, 2/3 to right side. So left was 1/3 underdosed and right 1/3 overdosed. And you guessed it: all my crabgrass breakthrough was on left side of the spreader.<br>Have generally had heavy breakthru only when site is not irrigated. A dry spell can allow soil to crack, so preemerg bond is also cracked?<p>----------<br>Jim<br>South Bend, IN

01-19-2000, 02:39 PM
I use split applications of preemergent. One in Feb. and then April. Have never had a problem with fall germination of cool season grasses.

Davis TLC
01-20-2000, 04:50 PM
Thanks guys. I appreciate the input. I thought there might not be a problem with the fall app. of weed-n-feed. I have seen instances where 2,4-D has been applied on a yard and then over-seeded and there was a very poor germination of the grass seed. I do not apply any post emergent until after 3 cuttings on new grass without any ill effects. <br>Thanks again.<br> <p>----------<br>Richard <br>Davis Total Lawn Care