How to Grow Potatoes in a Bag

Want to learn how to easily grow potatoes in a portable, space saving, and easy way that even apartment dwellers can do?  Read this blog post to find out.

We have rocky land, so growing potatoes in a ditch is not feasible.  It's hard for me to bend over because of my neck pain, and the stacked palettes didn't work so well a couple of years ago.  So, I bought 100 yds of premium weed blocker fabric.  I'll be able to make planting bags for years!

You can sew, glue or even duct tape the bags to make any size planter you want.  You can also use porous re-usable grocery bags or burlap sacks.  I've heard, though, that the weed blocker fabric works the best.

For potatoes, the bag should be taller than it is wide.  18" high is a good start.

Here's what you'll need:

• Assembled bag
• Seed potatoes (not grocery store!)
• Nitrogen fertilizer
• Loose soil mixture that won't compact
• Vinegar
• Marker or pen
• Masking tape

Seed Potatoes

• Don't use those potatoes in your kitchen you've had for 3 months
• Buy seed potatoes
• If they don't have sprouts, let them sit indoors in medium light until they have nice hearty sprouts
• Plant potatoes smaller than an egg, whole
• Larger than an egg, cut the potatoes 
• They should have at least one eye per 2" sq.
• Let the skin heal for a day
• Then plant

Fertilizer:

Each plant only needs a total of one-fifth ounce total nitrogen for the whole season.  Here's some math, but don't worry, it's easy!!

• Multiply 1/5oz x # of seed potatoes in the bag.
• (if  you have 4 seed potatoes in the bag you would have 4/5 of an ounce)
• Measure the nitrogen
• Part 1: Take 2/3 of the nitrogen you measured and put it aside
• Parts 2 & 3: Take the remaining nitrogen and split it in 1/2

Use your masking tape to keep track of dates to fertilize

• Part 1 gets mixed thoroughly into your initial soil
• Part 2 add to the soil about 6 to 7 weeks later
• Part 3 add to the soil about 2 weeks later

If you want to use manure for fertilizer, you'll need to mix it in the soil for the next season to allow the nitrogen to deplete.

Planting the Potatoes in the Bag:

1. Roll down the top edge of the bag to make bag height 8"
2. Fill the bag with soil until it is about 4″ deep
3. Mix in fertilizer well
4. Place seed potatoes on the soil surface, spaced evenly.  
• Use 4 seed potatoes for a bag 18" high and about 14" across
5. Cover with another 3″ of soil
6. Write the planting date, the days to maturation, and days to harvest for the variety of potato on masking tape and tape to the bag
7. Once the plants have grown to about 8″, unroll the edge of the bag about 4"
8. Add about 4″ of soil.
9. Water thoroughly
10. Repeat after they've grown another 8″
11. Repeat the process until the bag is full

Harvesting

• Use your masking tape dates to let you know when to harvest
• Feel around for a potato or two to see if they're the size you want
• Cut the vines down to the soil 14 to 20 days before harvesting (use your masking tape to make dates)
• Potato skins will toughen up after the vines die which lets you store them longer
• If you plan to eat them all right away, then you can harvest when you like the size of them

Tips

• Do not saturate the soil with water or your potatoes could rot
• Potatoes like acidic soil pH from 4.8 to 6.5
• Mix 1 T vinegar with 1/2 gallon of water
• Water (but don't soak) your potato plants or soil to easily increase the pH
• Write the planting and fertilizing dates on some masking tape and place on the bag to keep track of fertilizing and harvesting times
• If you plant different varieties in the same bag, put the masking tape labels near each potato to mark its individual dates.

Dates to Remember

Here's a handy list of dates you'll need to keep track of:

Day 0	Initial Planting (and Fertilizer Part 1)
Day 42	Fertilizer Part 2
Day 56	Fertilizer Part 3
? minus 14	Days to Cut Vines
?	Days to Harvest for the Variety

For example, if your potato variety takes 100 days to harvest, you would use these days:

Day 1	Initial Planting (and Fertilizer Part 1)
Day 42	Fertilizer Part 2
Day 56	Fertilizer Part 3
Day 86	Days to Cut Vines
Day 100	Days to Harvest

Want to use a spreadsheet to calculate for you?  Use these formulas:

Row/Col	A	B	C
1	0	Initial Planting (and Fertilizer Part 1)	[Enter 1st Date Here]
2	42	Fertilizer Part 2	=$C$1+A2
3	56	Fertilizer Part 3	=$C$1+A3
4	86	Days to Cut Vines	=$C$1+A4
5	100	Days to Harvest for the Variety	=$C$1+A5

Happy Potatoing!