The Great Tater Experiment
Recycled Coffee Sacks
I scrounge coffee grounds from the local java joint and add them to my garden. It dawned on me that coffee sacks are bigger than my pant legs, stronger, biodegradable and don’t look as weird. To me, the word ‘biodegradable’ also means no commitment.
I got my hands on a few used sacks and found they had many benefits over other container methods. Old tires were out of the question for both aesthetic and environmental issues, and having another large plastic garbage can to look at in the backyard was also a no-go. The newer polypropylene grow bags are neat but they still look like garbage bags to me.
I learned a few things about growing potatoes from trial and error and one of the keys is to mound up the soil after the stems grow several inches. This produces more potatoes because taters sprout and sprawl from the stem of the plant, not the roots. So the best containers for potatoes are tall, hence the stacking tire method that many folks use.
Jute is Cool
A jute bag can be plunked down anywhere – on a balcony, patio or garden bed. It looks natural and doesn’t stick out like a sore thumb. The material is woven so drainage holes come standard. Air flow and rot prevention are built in. It’s great to reuse something that already looks earthy.
If your sack once held coffee beans and has any kind of logo or print on it, it might even look cool next to your patio seating or flanking a bench.
A coffee sack will stay together for at least a couple of seasons. The natural fibers eventually break down and many gardeners lay them flat on the ground after use for weed control or as a mulch.
To inspire others to grow their own potatoes I put together a kit for my farmers market booth. It had three kinds of organic, gourmet potato seed plus a recycled coffee sack and easy instructions. Below are the instructions so you can do this yourself if you already have access to the potatoes and a suitable container or garden bed.
3 Easy Steps for Growing Potatoes in a Sack Above Ground
You will need: A recycled sack, seed potatoes and garden soil.
On potatoes purchased at the store: I have used organic potatoes from the store that have not been sprayed with a growth hormone to prevent sprouting. Certified seed potatoes are disease and pest free, and will probably give you a bigger harvest.
When to Plant: You can plant your seeds in the fall if you don’t get hard frost in the winter. Many folks in Southern California start potatoes in November! If you live in USDA Zones 1-7, recommend waiting until early spring to plant. As with any seed, results will vary depending on growing conditions and level of care.
Storing your Seed Potatoes Until Planting: If you cannot plant right away, store your seed in a cool, dark spot where the potatoes won’t dry out or freeze. Ideally, you would plant 1-2 weeks after you receive the seed. Keep each potato individually and loosely wrapped. Ideal temperature range is 35 to 45 degrees F. A garage, basement or unheated closet works well.
About Chitting: If you want to encourage your potatoes to sprout before planting, you can “chit” them. You sit them with eyes up in a cool place with some light and wait. Don’t let them touch each other. An egg carton is a perfect chitting tool. I don’t chit and I’m not a closet chitter. I’m just lazy and plant the potatoes without going through any pre-sprouting rituals. If you are into chitting, let them eye-out 2- weeks before planting and plant sprouts up toward the sky.
Step 1: Prepare the Sack
Add soil: Roll the edges of your sack down over the outside of the bag to make a very short bag about 4-6 inches high. Tuck in the bottom corners of the bag (optional) to improve stability of the sack and to conserve soil. Fill your sack with approximately 4-5” of loose soil. Potatoes can grow in a variety of soils – rich, sandy – even straw. Heavy clay soil may not be the best choice. If you want to fertilize the soil, do it now.
STEP 2: Plant the Potatoes
Prepare the potatoes: If a seed potato is large (more than 2.5” long) and has more than one eye, you can cut the potato into 1-2 inch sections (keeping an eye on each section). You’ll plant only 3-4 pieces in the sack. If your potato is small (1-2 inches), don’t bother cutting it into sections. Plant any extra seed in another container!
Some folks insist on waiting a day after cutting so that the cut area gets a chance to callous over. This is supposed to prevent rot. I don’t wait – I just plant it but if you are concerned about rot you can delay planting for a day. Do not let the seed potato dry up.
Plant the potatoes: Place the potatoes on top of the soil, eyes/sprouts pointing up toward the sky. Again, plant the seed at least 6 inches apart.
STEP 3: Cover the Potatoes – Then Mound Up Later
Cover: Top your potato seed with 4”-6” of loose soil.
Mound up the soil: Once the leafy plants push through the soil (2-4 weeks) and the green tops grow more than about 8” tall, mound up the soil around the plant to promote growth of more potatoes under the mound. Leave some of the leafy vine above the soil (4-6″). Mounding Up is one of the secrets to getting a larger harvest!
Watering and Fertilizing: Keep moist at all times but don’t over-water (to prevent rot). Shelter the bag if you have excessive amounts of continuous rain. Don’t let your sack dry out. Soil amendments added when “mounding up” may increase your harvest and improve plant health. We use a combination of compost, worm castings and kelp brewed into a compost tea.
Harvest! After approximately 80-100 days, the plant will stop flowering and you’ll see signs that it’s starting to die (turns yellow or brown and withers). Wait 2 more weeks after the plant shows these signs and then try to harvest! Waiting allows the skin of the potato to set. Dump the sack over or carefully dig the potatoes up as you need them. YUM! If you harvest them all at the same time, store as you would other potatoes, in a cool, dark spot where they won’t dry out.