Why would you want to stop you
potato plants from getting taller?
You can get more
potatoes from a larger
plant! As it gets taller, hill the soil up around it, so it's deeper...
potatoes will develop between where the roots start, clear up to the soil line, if you keep hilling up as it grows.
Maybe the reason your neighbor has smaller
plants is because your soil is richer.
potatoes just love high levels of nitrogen & potassium, & apparently that's what you've given them by amending the soil with steer manure.
Sounds great to me!
Good luck! (Got pictures?)
Welcome to the forum, by the way!
TLC works wonders in gardens... we'd like to hear more about what's
growing in yours! This place is full of friendly people who are willing to help (& we're always looking for help with our gardens, too)... maybe you have some ideas & gardening experiences that you'd care to share with us. We're just like 1 big family & look forward to getting to know you better!