Question
I would be closest to Bangor Maine.  I am in Southern NB Canada. My question is what would you recommend for spring time fertilization during the spring thaw?  Is liming the lawns a good idea?  What type, and when, should I apply fertilizer?

Answer
A lawn in your area should be fertilized in late spring, early fall and late fall. Avoid fertilizing too early in spring and during hot summer months. End May, early September and end October would be good times.

I recommend a fertilizer with high nitrogen contents (most fertilizers formulated for lawns are ok). I recommend using fertilizers without herbicides/insecticides (weed and insect killers). Always apply to a dry lawn and water in immediately using plenty of water, or apply when rain is expected. Most lawn fertilizer brands are fully acceptable.

Liming should only be done if the pH value is below recommended target. The target is 6.0-6.8 in which range most grasses grow adequately.

Have a soil test done and the pH determined before liming. If pH is below 6.0 lime. If above 6.0 do not lime. Garden centers will sell small pH test kits for a nominel fee. If you buy one of the packages which comes with small tubes and pills which is to be mixed with soil and water, then use distilled water, or better collected rain water, when doing your tests.

Lime takes about 6 months to change the pH level. You can lime anytime of the year when the ground is not frozen. You should avoid liming and fertilizing at the same time, however. A good way to introduce a regular liming program, is to take a soil test before fertilizing the first time in early spring. If you need to lime, do so mid summer or about 30-45 days after your last fertilizer application in fall.

Usually taking a soil test in early spring every year is all you need, and liming should then be done the following winter. The advantage of early winter fertilization is that the lime gets to work over the winter with normal thawing/freezing cycles which works it into the soil pores. Mid summer is another option for liming.

The reason I recommend early spring soil testing is that the soil pH is not affected by the acidifying fertilizers or by lime added recently. If soil tests are done early spring and lime added mid summer or late winter (seperated from fertilizer applications) you should be ok.

Use between 30-45 lbs of caltric lime stone per 1000 sq feet lawn area (about 15-20 kgs per 100 sq meters). I usually buy pelleted lime which works just as well as the powdery stuff, but it is easier to handle and distribute.