Organic or Traditional lawn fertilizer: which is safer for areas with young children?

Question

I have a new lawn that was started in late August in the Boston (MA) area. The installer says it's time to apply fall fertilizer. My new lawn looks pretty good: there was broad germination; there are some bald spots; and in the shade there's some thinner uptake. It's starting to yellow slightly. I'm currently watering twice a week for approximately 30 minutes.

I have young children who want to play on the lawn, so I want to be careful about exposing them to the fertilizer. I bought two fertilizers with the plan to use one of them, and I could use some help answering questions in order to pick one.

The two fertilizers are:

1. Scotts® Turf Builder® WinterGuard® Fall Lawn Food -- This has no pesticides and a fertilizer mix of 32-0-10
2. Scotts® Natural Lawn Food -- This has no pesticides, is "organic" (bone meal) and has a fertilizer mix of 11-2-2

Questions:

1. Is the traditional fertilizer safe for my children? The online documents say "Kid and pet friendly when applied as directed."
2. Is the organic one any safer? Online says "Kid and pet friendly."
3. The organic bag is 2x larger by volume even though it covers only 80% of what the traditional one covers. Why is that?
4. By percentage, the organic one (11 + 2 + 2 = 15) has less actual fertilizer than the traditional (32 + 0 + 10 = 42). Does that matter much?
5. Should I use a broad fertilizer for a new lawn (organic one in this case) or the fall mix (traditional one). It's a new lawn, so root growth is key, which is why I would think the organic one with its (admittedly small) phosphate contribution would be good.

Any advice about fall fertilizers for a new lawn and fertilizers with kids is much appreciated.

Answer 1

This is a difficult one if you have children. First, let's deal with the two fertilizers you've mentioned - the first one, non organic, has a much higher Nitrogen level, as you've noticed, nearly 3 times the level of the organic one, and is much more suitable for use in Fall. Because its an autumn formulation, it will take longer to break down than the organic one you have, which does not seem to be specifically for autumn use. It also means you need less of it so its usually spread more thinly, and its the one I would choose in these circumstances.

The usual advice where children will be playing on grass after treatment is to use a liquid which, once its dry, is no trouble to either pets or children, and this is particularly useful in summer. However, because its Fall, you do actually need a product in granular or dry formulation because the idea is it breaks down gradually, over a much longer period of time than a liquid would do, which is more or less instant. Regarding the difference between them, in theory, either product could burn skin if the person is in prolonged contact and is particularly sensitive, but I imagine your children won't be lying for hours on the grass with bare skin.

Although the idea of an organic product seems better, in practice, bonemeal can produce dust, attracts various animals who think its something interesting to eat, and isn't any safer from a skin point of view when compared with the non organic product. So, on balance, I'd recommend the non organic version, carefully spread at exactly the right rate and no more, following the instructions to the letter. You should exclude children and pets whilst the treatment is carried out, and it would be better to keep them off the area until its been well watered in over a couple of days or so. I know the instructions say no need to water in, but if your sense of smell is good, after such a treatment is spread, the first couple of times it gets wet you can actually smell the treatment in the air, so I'd water it in regardless.

I do have one caveat though - I would check with Scott's first before using anything, to make sure that any product you choose is suitable for a lawn which has only been down a couple of months. If its like Scotts products here in the UK, there should be a contact phone number on the packaging for queries/customer service. It would also be interesting to find out what product, and its NPK ratio, the installer would use himself...