Q.to raise my garden to at least a foot…will it kill my established tulips and Daffodils?
My flowerbed has receded through the years, when watering the water basically runs right out leaving my flowers dry…I would like to raise my garden about 2 foot .. will it kill my 20 year old Tulips and Daffodil’s?

Certified GKH Gardening Expert
If they have never been dug up and replanted before, then this is exactly what they need during dormancy. They need thinning every one or two years, sometimes going 5 years or so between thinning. This will be the only proper way to fix it. Otherwise, it only offers a "cosmetic" solution.
These two articles will help you:
https://www.gardeningknowhow.com/ornamental/bulbs/daffodil/dividing-daffodil-bulbs.htm
https://www.gardeningknowhow.com/ornamental/bulbs/tulips/dividing-tulip-bulbs.htm