Answer: If you have several projects to complete, I'd suggest choosing one and finishing it before taking on the others. This way you can do the job right and you will be rewarded for all your work for years to come. If you have existing vegetation, you'll want to remove it. Mark off the flower beds and the lawn area. If you work on the flower beds now, you can work on the lawn later in the fall. Fall months are good months to plant a lawn.
The best way to ensure healthy, happy plants is to prepare the soil prior to planting. Do this by spreading 4-5" of organic matter over the entire flower bed and then digging it in to a depth of about 8". Then rake the soil level and plant your annuals and perennials. Once you've finished planting, mulch over the bare soil with organic matter (to help suppress weeds and slow water evaporation). When the flower beds are complete, you can work on the lawn.
Rototill the area, add some organic matter and starter fertilizer, then rake the area smooth. Broadcast your grass seed, cover it over with a thin layer of peat moss, and keep it watered. Grass seeds usually sprout in 7-10 days.
Best wishes with your new landscape!
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