Only use a weed and feed if the weed infestation is completely uniform over the entire lawn and all species of weeds targeted will be affected by the herbicide in the weed and feed. This scenario doesn’t occur often, so it is more likely the use of an herbicide and a fertilizer separately will be needed. If the weeds are uniformly spread over the area to be treated, match the appropriate weed and feed product to your grass, the seed you have recently applied or want to apply, and the time of year.
Herbicides can target weeds before they germinate from seed – pre-emergent – or as developed plants – post-emergent. Before you seed, you can use a non-selective, post-emergent herbicide to control any weeds in the area to be seeded. Most of these can be applied up to two weeks before seeding to control any existing weeds. Herbicides should not be used after seeding until the new seedlings are established. Mowing and spot treatments can be used to control weeds until the seeded area is actively growing and requires only maintenance watering. Establishment times vary depending on the type of seed you use and your weather conditions.
Weed and feed fertilizers are often used in combination with seeding. Weed and feed formulations consist of two components: a herbicide to kill weeds and a fertilizer to strengthen the turf. The herbicide will weaken the grass as well as the weeds and the fertilizer will strengthen the weeds as well as the grass. When applying seed over a weed and feed application, remember that some weed and feeds can prevent grass seeds from growing.
It’s important to know a little about herbicides so you can make the best choice for when to apply seed in an area that has been treated for weeds. The most common types of herbicide in weed and feed products are selective and systemic. Selective herbicides target a species of plant to kill while systemic herbicides work by being absorbed though the roots and then transported throughout the plant, killing it from within. Read the bag label to see what kind of herbicide is used in the weed and feed you are considering using or have used. The bag label will tell you how many days you must wait before applying seed to a lawn that has been treated with that product.
It is important to know what kind of grass you have growing or want to have growing. Certain chemicals act differently on different species of grass and weeds. For example, the common herbicide 2,4-D is toxic to some cultivars of St. Augustine grass (Stenotaphrum secundatum), which grows in the area roughly covered by U.S. Department of Agriculture plant hardiness zones 8 through 10. Another common herbicide, atrazine, is potentially lethal to grass when applied in temperatures above 85 degrees Fahrenheit. Use the instructions on the bag of each weed and feed product to determine how it will affect seeding.
Sara DeBerry is a graduate of the University of Florida holding a masters degree in environmental horticulture and a minor in entomology and nematology. DeBerry has been writing for government agencies since 2004 and has published peer reviewed scientific articles during her studies at UF.
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Maintaining a healthy lawn includes mowing, weeding, watering, and fertilizing. However, fertilizing isn’t always necessary. Over-fertilizing your lawn will make the grass grow more vigorously, causing you to have to mow more frequently or lead to run-off which ends up in your local watershed.
The right weed-and-product can improve the health and appearance of your lawn. Ahead, get our top tips and recommendations for navigating the available options—and don’t miss our top picks!
Some weed-and-feed options out there feature slow-release formulas so you don’t have to fertilize as often. However, to achieve good results plan on treating your lawn at least once every 8 weeks from the start of spring.
In general, grass species are divided into two categories: warm season and cool season. The seasons do not refer to the time of year, but the climate and average soil temperature range.
Keeping your lawn looking lush and green means that you need to weed frequently and apply fertilizer at the right times of the year. Altogether, it can be an energy- and time-consuming exercise, especially if you have a large yard. Although you may be able to dig up a clump of crabgrass or dandelion by hand on occasion, it’s not plausible to hand-weed or fertilize an entire lawn regularly.
Unfortunately the seed you already put down is not going to germinate. But it sounds like you know that.
I think it is less likely that you get growth and then the young grass dies as the roots go deeper, more likely is you won’t get growth at all or significantly less than you had planned for (say 1/4 or 1/3 germination rate, btw totally just throwing a random number out since I have no idea if anyone could give a good estimation).
POLL: Biggest Garden Menace?
You can keep trying every couple of weeks and not need to rake up the “dead” seed so no worry of overseeding as if grass does take it will eventually get the nutrients from the decomposing seed and will also supply a bit of water retention properties when watered.
Just trying to find any possible solution.
Thanks in advance for your ideas!