Q.Top-dressing established beds
Hello,
When I plant new flowers, I amend the soil with compost. Now that my garden is more established, I’m wondering if I should top-dress each spring with compost and/or fertilizer to ensure the soil has nutrients for the plants. Is it necessary to do both? Or if I top-dress with compost each spring, can I forgo fertilizer?

The only way to really know if the soil is nutrient rich is a soil test.
Top dressing is a great way to amend soil but if blooming plants receive too much nitrogen they may have poor flower performance.
Some plants need additional fertilizer for healthy growth.
You may want to research your plants specific needs and make decisions about fertilizer or compost applications from that information.
Your County Extension Office can do a soil test for you for just a few dollars.
Here are some links with more information.
https://www.gardeningknowhow.com/extension-search/
https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/testing-soil.htm
https://www.gardeningknowhow.com/special/organic/the-importance-of-soil-for-an-organic-garden.htm
https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/improving-garden-soil.htm