I have leftover lawn fertilizer (16-6-8) from the time I used to have a lawn. Can I use this fertilizer for anything else, trees, vegetable garden, xeriscape plants, bulbs? If so, how would I adjust its application. Thx for your help.
Absolutely you can use 'lawn fertilizer' for other plants. What you HAVE TO know is the entire chemistry of your fertilizer in that bag and what the your soil tests show and what you are trying to achieve.
For instance, vegetables, such as leafy greens could possibly be ok with this high nitrogen fertilizer. Does it have any herbicide included? Then DO NOT USE IT EVER AGAIN. Is it sulfur based? How much iron?
Purchase proper fertilizers and only apply them judiciously! Read that label. Organic, slow release fertilizer is the best. Lower numbers are better...fertilizer IS NOT FOOD. You are just replacing chemicals those plants we stuck in the ground need and is not available in your soils.
If you want flowers or most vegetables where you want reproductive growth you have to have nitrogen being the lower of the 3 numbers. I used this stuff my hubby bought that claimed it was for vegetables...6- 5- 4. 6% of the bag of stuff was actual nitrogen, 5% of the bag (weight) was phosphorus and 4% was potassium. And all I got was great leafy growth and little fruit/vegeys/flowers. That first number has GOT to be lower of the three if you want flowers or fruit.
I'd use that stuff on your compost pile to help it decompose. Now there is a great application of high nitrogen as the decomposers have to have nitrogen to do their thing. Not a lot and a bit of moisture will help you decompose your kitchen scraps. I am glad you've gotten over lawns. Took me years to learn all about that monster...a little lawn is fun...too much is just dumb...oh, unless you are feeding animals with the grass...that is different. That is a pasture not a lawn...