How to Grow Potatoes in Grow Bags
Check out the video version of this guide on my YouTube channel
Did you know you could grow potatoes in grow bags? There are several benefits or reasons why you should grow them in grow bags.
1. No digging them out at harvest time. Just dump the bag.
2. Grow bags are a great fit for small gardens
3. Potatoes don't like very wet soil or the potatoes rot. Grow bags dry out easily.
Cultivar Selection
⦁ Colors - white, brown, red, yellow, purple, pink, blue. In general the dark colors like purple and blue loose their color when boiled but retain color when roasted.
⦁ Texture & Use
Russets - hard brown skins with white flesh. Starchy and dry. Perfect for frying, baking, and roasting. Falls apart when added to soups or stews.
⦁ White Potatoes - Thinner light brown skins, white flesh. Dual purpose, works well fried, roasted, and stewed.
⦁ Waxy Potatoes - Example is Yukon Gold. Holds their shape well so best for potato salads, and soups.
⦁ Fingerling Potatoes - Slender and long potatoes. They are smaller in size so best to boil or roast them whole.
⦁ New Potatoes - Immature potatoes that are harvested early while the skin is still tender. They have a shorter storage life because of the immature skin. I grow Red Norlands because they do well in Florida and are early maturing.
⦁ Early or late maturing - Indeterminate potatoes have a later maturity date than most other varieties. Determinate potatoes (like Red Norland), are early maturing.
⦁ Please get seed potatoes that a certified disease free. I don't recommend starting your own slips from grocery store potatoes as they have been sprayed with growth inhibitors.
When to Plant
⦁ Plant seed potatoes 2 weeks before your last average spring frost date. Find your average spring frost dates on www.plantmaps.com.
⦁ My garden as an example - Zone 9B in Central Florida - you can start planting in January and February. My last average spring frost is the 2nd week of February.
How to Plant in Grow Bags
⦁ Use a minimum of a 5 gallon grow bag. The bigger the better. I like 15 gallon grow bags. You can find the same ones I use HERE.
⦁ Plant 2 seed potatoes for every 5 gallons of container size.
⦁ Add 6-8 inches of soil/compost to the bottom of the grow bag. Drop in the potatoes with the "eyes" up.
⦁ Sprinkle some all purpose organic granular fertilizer, and some extra potassium & phosphorus fertilizer.
⦁ Add enough soil/compost to cover the potatoes. Don't let them be exposed to the sun.
⦁ The potatoes will sprout some stems. When stems reach 7-8 inches in length, add more soil just under the top set of leaves. Keep doing this as the stem grows, until the top of the grow bag is reached. This process is called "hilling".
Sun Requirements
⦁ 8 hours of full sun, mine are happiest with afternoon shade. Too much heat will stunt potato growth, they wont produce well.
⦁ When the soil temperature gets above 80F, the roots are too hot and production declines.
Soil Requirements
⦁ Soil rich in organic matter and some what fluffy so the potatoes can develop.
Water Requirements
⦁ Potatoes easily rot in soil that is too moist. Allow the soil to dry out in between watering. Growing in grow bags helps with drainage.
⦁ Stop watering when the foliage begins to turn yellow and die off near harvest time.
Growth Habit
⦁ Potatoes are part of the nightshade family like tomatoes. Just like tomatoes, they form roots wherever their stems touch soil. Plants get bushy and sprawl out low to the ground.
Pruning
⦁ Not necessary, but remove dead, old, diseased leaves when ever possible to prevent spread and not attract pests.
Fertilizing
⦁ Potatoes are a root crop. Add plenty of phosphorus and potassium heavy fertilizers to promote large root growth. Apply at the time of planting.
⦁ the first application is when you plant the seed potatoes. Sprinkle some general/balanced fertilizer to give the plants a good head start.
⦁ Apply more fertilizer after "hilling up" for the first time. Try to use a fertilizer that has more potassium and phosphorus than nitrogen.
⦁ The final application will be when you hill up for the 2nd time. Again, use a fertilizer that has more potassium and phosphorus than nitrogen.
Pests
⦁ Black and yellow-striped "potato bug" and Colorado potato beetle - They feed on the leaves of the plant and can spread to other crops like tomatoes, eggplants, and peppers. Spray with BT/spinosad when you see the soft bodied larvae.
⦁ Worms - Leaves look munched on, small orange, green, or black balls on the leaves = eggs and poop. Nocturnal. BT (bacillus thurigensis) organic spray (link to Amazon). Washes off in a few days and is safe to eat.
⦁ Aphids - They tend to attack the pea tips. Spray them off with water. Usually aphids are an ant problem so treat for the ants. Spray with peppermint, rosemary, or neem oil. Plant lots of trap crops like nasturtiums, southern peas, kale.
⦁ Use Safer brand organic insecticidal soap to treat - aphids, earwigs, leafhoppers, mealy bugs, mites, soft scales, spider mites, and whiteflies. Find Safer Insecticidal Soap HERE.
Diseases
⦁ Leaf diseases - powdery mildew, blight, yellowing spots, spray with 1C hydrogen peroxide (3%) per gallon of water.
⦁ Bacterial wilt - Plants look like they have wilted all of a sudden and due quickly. There is no cure for this pathogen in the soil. Proper crop rotation is important.
⦁ Potato scab & canker - potato skin looks scabbed or lesions. This is a pathogen that survives in infected soil and plant material/debris. Plants are weak and production is reduced.
⦁ Potato tuber rot - caused by too much water in the soil.
Harvest
⦁ I recommend to wait at least 120 days to get decent size potatoes. They are ready for harvest once the plants yellow and die back.
⦁ Dump one grow bag to test how mature the potatoes are. The skins should be thick/firm and not rub off easily.
⦁ Don’t leave the potatoes exposed to sun light. It will cause them to turn green and develop a toxin that will give you an upset stomach if eaten.
⦁ Do not wash the potatoes after harvest. Brush off extra soil. The soil helps them dry out and cure for storage.
⦁ Cure the potatoes so they last longer in storage. Place all of the potatoes in a drafty box or container with good air flow. Cure for 2 weeks in temperatures of 45F-60F. This helps the skins to harden.
⦁ Store potatoes in a cool dark place.