Q: Now that spring is coming, what is the timing and sequence of killing weeds and fertilizing?

Weed controls can be applied any time that weeds are actively growing. Seeding can be applied anytime during the spring that the soil is not frozen or covered. First fertilization application can be applied now. If you want to use a pre-emergent to control crabgrass (ie.Scott's Halts) do not try to reseed now, but wait till fall. The pre-emergent will stop crabgrass from sprouting later in the year, but will also stop new grass seed from
sprouting as well.