Member Since: 02/24/2016

recent comments

Re: Build Your Own Potato Growing Box

@22chuckie I don't know anything about sweet potatoes, but I have grown white potatoes—Irish Cobbler, Kennebec and Katahdins. If you had rich garden soil you did not need to add manure. Manure adds nitrogen which encourages leafy growth, which you had—good for lettuce & spinach but not so much for spuds. Potatoes love wood ashes which provide potassium to grow strong stems (potatoes form on the stems), and phosphorus which promotes roots, flowers, fruits & seeds.
The directions in the article say to cover no more than 1/3 of the plant—4" on a foot high plant, so that might be another issue. What you add to cover the stems those 4" matters—go back to #11 in the instructions. Spuds need to grow in the dark, so covering the stems has more to do with the dark than the nutrients in the medium—some people use only a straw mulch. The advantage of compost or the other mixtures that actually go into compost is that they are less weighty and the nutrients are a naturally balanced soil builder that you can use in another part of your garden (preferably not where you grow other plants susceptible to the same diseases).
You say nothing about watering, and neither does the article, and I'm not familiar with your climate. I will say this about the size of your box—it's very very hard to access the middle. My previous square foot garden boxes were 4'x8', but when I moved I built 3'x6' (my joints are getting stiffer, so it's easier to reach 1.5' than 2' to the middle, making it easier to pick off potato beetles if I see any.
I suggest the Organic Gardening Magazine and Mother Earth News website(s). In particular Mother Earth has an excellent garden planning section with a TON of information on plants, graphing software, and you can choose between square foot gardening and row gardening. When you set it up you also tell it your zip code & email, and they will send you reminders when to plant different crops. It's free unless you want to save your garden layout from year to year (for crop rotation), in which there's a modest annual charge. Good luck!

These links will help you learn more about N-P-K fertilizers.