If I leave my lawn alone (except for pulling all saplings), how high will the various grasses, goldenrod, etc. become? I live in Connecticut.
Depending on the types of grasses (and weeds) growing in your lawn, I'd say anywhere between one to two feet, though some types of weeds can get over three feet. If you would like a prairie-type lawn rather than grass, it is best to clear your lawn and begin anew with appropriate seed. This article will help: https://www.gardeningknowhow.com/special/spaces/prairie-garden-design-tips.htm
I live in Lecanto, Florida (Zone 9). My 'fireworks' goldenrod just grows like a ground cover, only getting 3 inches tall and not flowering. However, a dwarf variety next to them grows well and flowers. What is wrong?
Not having enough Potassium for that variety of plant is all I can think of right now.
Can goldenrod cause allergic reaction?
Technically speaking, any plant can cause allergy but goldenrod is not known as a plant that commonly triggers allergy symptoms. It happens to bloom at the same time as ragweed, a well-known allergen. Since pollen travels on the wind, it is difficult to pin down the culprit without testing. If you react allergically to ragweed, daisies and marigolds, you might also react to goldenrod as it is in the same family of plants. (WebMD)
I have a one-acre hillside I wish to plant to aster and goldenrod for fall returning Monarchs and bees. What is the best mix of the two seeds for balanced growth? Do I need a 50-50 distribution or should I plant more of one than the other? The fact that the two plants grow well together does not mean insects feed equally on them. And, does one outlast the other producing nectar as you head into late fall?
I believe that starting with a 50/50 mix will be your best bet. No matter what you do, nature is going to establish the proper ratio over time. What you don't want is to start with what we, as humans, assume is a good ratio, only to lose the crop.
https://www.gardeningknowhow.com/ornamental/flowers/asters
https://www.gardeningknowhow.com/ornamental/flowers/goldenrod
https://www.gardeningknowhow.com/ornamental/flowers/asters/aster-companion-plants.htm