Question
Hi Ken,  I live in Michigan, Metro Detroit area,  How often should my lawn be fertlized yearly, and when is the earliest the first application should be applied, should it be a weeed and feed or just a start up fertilizer and the weed and feed on the second application?  reason I am asking is my fertizer guy called and wants to put down the first application,  I think its to early (march 7) and the ground is still frozen several inches down.  I don't mind paying, I just dont want to waste my money.  Thanks for your time,  Leo

Answer
My recommendation is to fertilize in late spring, early fall and late fall. I do not recommend fertilizing too early in spring and do not fertilize during hot summer months.

There is always a lot of discussion whether to fertilize in early spring or not. Most county extension offices and turf professionals recommend fertilizing only after the soil has warmed by itself in spring. Definitely never fertilize when soil is frozen (that is a complete no-no). Also remember that soil warm slower than air temperatures in spring so it is not uncommon for the soil to be frozen even in april.

Fertilizing early in spring (e.g. april) will lead to lots of top growth and will look really well (healthy, green and lush) but will also deplete the reserves stored in the roots very fast. Waiting to fertilize until later in the spring will provide for healthier turf which is also capable of handling a hot, dry summer much better. If you deplete the recourses in the roots in early spring, there is less resources to keep the lawn healthy in summer.

During hot summer months, lawns in our area is generally stressed. Keeping the lawn green and active is difficult with high temperatures and draught periods. Also grass in Detroit can not build resources in summer once soil (soil!) temperatures exceed 75F.

Most of the fertilizer should be provided in fall. In early fall, you can thicken up the lawn and get good carbohydrate (energy) storage in the roots, crowns. Fertilizing in late fall is even better as top growth is minimal but energy storage is still good.

My recommendation is this:
- fertilize in late may, early september and late october.
- Do not fertilize too early in spring and do not fertilize in summer at all (no matter what lawncare companies tell you)
- apply weed-and-feed lawn fertilizer (against broadleaf weeds) in fall only. Broadleaf weeds are such as dandelions, clover, etc.
- otherwise use regular lawn fertilizers.

There is only one type of fertilizer which could warrent fertilizing earlier in spring.

This is fertilizer with crabgrass control but it should not be applied now. First half april is more appropriate. You can generally time this application by the appearence of the yellow forsythia flowering bushes. Otherwise, as long as it is applied by mid april you are in most circumstances fine.

Not all lawns need crabgrass preventer, however. Only those with bad infestations last year should be candidates. If you did not have bad crabgrass infestations then skip the application. If you are in doubt, skip it. If you had a lots of light green grassy looking weeds last year, then you can use it, but it is really not as critical as the commercials would have you think.

If you decide that you must provide crabgrass preventer, then the preferred way is to have a landscaper/lawn care company put it down without fertilizer. Professionals have access to the material in liquid form.

Home owners who wishes to put down the crabgrass barrier themselves typically have to rely on fertilizer w/crabgrass preventer included. And, it must be put down by mid april in your area as mentioned. This goes against my advice of not fertilizing until mid may, and you have to weigh the advantages of crabgrass control with advantages of lawn health.

Therefore, only if you absolutely need crabgrass preventer put down (past bad infestation) then you can trade off and give fertilizer in early april. Then postpone your second application to early june.

If you use a professional lawn care company, then they should not have to use the fertilizer w/crabgrass preventer. They should just use crabgrass preventer without fertilizer. I am not sure how big the outfit is that you are using ? Are they a local type mowing company who will also fertilize your lawn, or one of the big name companies with a wider product line of their own ? If their involvement in fertilizing is only buying and applying home owners types then they may only have access to the mixed fertilizer w/crabgrass barrier.

Let me explain a bit about crabgrass:

Crabgrass is an annual grass plant which grow from seeds which germinate (sprout) in early spring and result in light green grassy weedy growth in summer. This plant must be controlled by a chemical crabgrass control barrier in very early spring. Once crabgrass seeds germinate (soil temperature dependent) it is too late to put it down later. Therefore, if crabgrass is a concern, you must fertilize early (if fertilizer is mixed with crabgrass preventer), or the barrier must be down in it's pure liquid form in early april by a professional.

In winter, the crabgrass grass plants die back (annual) but the plants will have produced seeds in the fall and the dormant seeds will then germinate the following spring.

This is reason why crabgrass is handled by a liquid barrier in spring because it prevents crabgrass seeds from germinating and you break the weed life cycle. If you did not have a bad infestation last year, you will probably not need the barrier and therefore you can wait to another year.

So back to my recommendation:
- if you need to control crabgrass, do so in early april and then fertilize in june, early september and late october. Do not fertilize in mid summer
- crabgrass preventer is not always required and if you anyway pay a professional company, I would expect them to use a liquid crabgrass barrier in early spring and also for them to postpone fertilizing to late may.
- if you want to handle crabgrass yourself, then you may have to trade off and buy a fertilizer w/crabgrass barrier included. You then have to fertilize earlier than normally recommended.
- if you do not require crabgrass barrier (and many lawns can do without) then do not use it.

Too many lawncare companies are too quick to fertilize and use too much fertilizer at the wrong periods of time. I would recommend that you ask them to fertilize in late may, early september and late october and not a whole lot else.

-- Kenneth