What Is THE Best Fall Treatement For A Lawn Renovated In 2015 That Subcummmed to Crab Grass?
(1) We live on a partially, heavily wooded lot. In the past we fertilized three times in autumn. Do you still recommend such a program? If so, what type of fertilizer would I use? (Formerly I used 10-10-10 and on the third month, November, I'd use a Winterizer type.) Folks at the garden centers tell me to concentrate on the middle and last numbers, not the nitrogen content. Should I also think about aWeed/Feed? I did not fertilize in September because it was too dry. (2) What do you suggest for over seeding? When do I attempt this? (3) Another matter: I used the corn gluetin in spring and I was thrilled with a beautiful lawn. However it rapidly declined after July 4. What do I use next spring?
Howard County Maryland
1. We do not recommend fertilizing 3 times in the fall. Two times is the recommended approach. Please read over our fertilizer schedule: http://extension.umd.edu/hgic/umd-extension-lawn-fertilizer-schedule-home-lawns The spring fertilization is for poor or new lawns, or those that did not get fertilized in the fall.
Because phosphorus (2nd number, i.e. middle number, in the 3 number fertilizer ratio) is a major pollutant of the Chesapeake Bay, there should be NO phosphorus (P) in lawn fertilizer unless a soil test from that year says that it is low.
Also, potassium (K), the 3rd number, lasts a long time and is not usually necessary.
So, the most important nutrient is the 1st one, nitrogen (N). You DO want nitrogen, just not too much because, once again, it can be a big pollutant in the Bay. Most LAWN fertilizers sold in the state of Maryland now follow the recommendations in the link above. 10-10-10 is used in vegetable gardens, which have completely different needs than lawns.
2. Please read the overseeding info in this publication from our website: http://extension.umd.edu/sites/default/files/_images/programs/hgic/Publications/HG102%20Lawn%20Estab... Fall is always the best time to overseed.
3. Corn glutin is not a very effective weed killer. It must be used repeatedly over several years to reach minimal effectiveness. It also contains nitrogen, so in that respect it works like a light fertilizer, and maybe that's why your lawn looked good. We don't recommend it. To decide what herbicide to use in spring will all depend upon what weeds you are trying to irradicate. You may want to click on the Weeds section of our homepage and try to identify your lawn's weeds.