Few foods have had as great an impact on civilization as the potato. Since it was first brought from the heights of the Andes Mountains in Peru to the lowly dinner tables of the European poor, it has become one of the largest and most important crops grown in the world today.
Not only is it tasty and nutritious, it has a host of other benefits. Rubbing freshly cut potato or potato juice on the skin promises to relieve aches and pains. And carrying a potato in your pocket is supposed to alleviate a toothache. We don’t have room to go into all its uses here, so let’s just say potatoes are versatile.
Another reason for their popularity is that, when properly cured, they store well. We’ll discuss how to cure them later. First, let’s learn how to grow them.
In North Texas the best time to plant potatoes is usually in February, or about 3 weeks before the last spring frost. If planted too early, the tops can be frozen off by spring frost.
Curing Your Crop
Let’s be honest, potatoes take some effort on your part. They need to be cured both before planting and after harvesting. Additionally, you will need to regularly “hill” them during the growing stage. However, if you persist — and follow the process below — you will be richly rewarded.
Use Only Certified Seed Potatoes
Potatoes are not usually grown from seed. Although the flowers of the plant produce seeds, those seeds may not be “true to type” which means that the seed may not yield the same type of potato as the original plant. (The exception is with heirlooms and other open-pollinated varieties.)
To get the kind you want, you need to grow them from pieces of potato from the original plant. These pieces are called “seed potatoes.” But before you cut up your surpermarket spuds, it’s important to know that grocery store potatoes are usually treated with a growth inhibitor intended to keep them from sprouting. If you try to plant them in your garden, they will not take root.
For planting, you should only buy certified seed potatoes from a garden center or plant nursery such as Marshall Grain. Certified seed potatoes are guaranteed to be untreated and disease-free.
Varieties for North Texas
Marshall Grain typically offers several varieties of red, white, and yellow potatoes, such as LaSoda (red), Kennebec (white), and Yukon Gold (yellow). All of these varieties can be harvested as either “new” potatoes or “cured.”
New potatoes are usually harvested early while the tubers are still small and immature. They don’t last as long as cured potatoes, but their skin is soft and tender. New potatoes should be eaten within a few days of harvest.
If you prefer larger potatoes, wait until the tubers are fully developed before harvesting. Curing them makes the skin rougher and less susceptible to damage. Cured potatoes can last for several weeks in a cool, dark cupboard, or even longer if stored in the refrigerator. When refrigerated, the starch in the potato will slowly convert to sugar, so if they're chilled for very long they'll taste sweet.
The Eyes Have It
As mentioned above, you will be growing your potatoes from pieces of another potato. When shopping for seed potatoes, choose those that have lots of buds or “eyes.” New growth will sprout from those spots and grow into plants.
So why cut it up? Why not just plant the whole potato? The reason is because too many eyes on a large potato will create a crowded, multi-stemmed plant, with each stem competing for food and moisture, and in the end, bearing only small potatoes.
As you divide your potato, make sure that each piece has at least one good eye. Most people prefer to leave 2 or 3 eyes per piece. The seed piece provides food for the plant until it develops a root system. If the seed is too small, it will produce a weak plant.
Each seed piece will produce one plant and one plant will generally produce about 5 to 8 potatoes.
Curing Your Pieces
Next, cure the cut pieces. Either set them out in the sun or place them on a table or counter in a warm (about 70°F), moderately lit room for 3 to 6 days. Another option is to put them in a dry paper bag for about 5 days before planting. As they cure, the potato pieces will become calloused, which helps prevent rotting.
Where to Plant
Potatoes need full sun and loose, well-drained soil that is slightly acidic. Poorly drained soils can cause poor yields and heavy clay or compacted soils will stifle tuber development. Within those guidelines, there are an endless number of ways to plant them. The most common way is to dig a trench in the ground and line them up in rows. Another popular technique is to grow them in an elevated garden. These could be created from straw bales, tires, and wooden raised beds. Still others recommend grow bags, trash cans, and other types of planters.
If you plan to use any type of raised bed or container, we recommend Soil Mender Raised Bed Mix. It has everything you need right in the bag.
Depending on the health of your soil, you may also want to work in some organic fertilizer. Since potatoes are root vegetables, they need phosphate to form tubers. Use an organic product with a high middle number (such as Rabbit Hill Farm Buds & Blooms 6-8-4) or work in some soft rock phosphate (0-3-0).
We recommend that you also rub each seed potato with Dusting Sulfur before you plant to prevent common soil fungus from attacking your plants.
Plant your seed potatoes about 3 inches deep and cover them with soil. Don’t cover them too deeply or they will struggle to develop and be more prone to disease and decay.
Warning: Never eat a green potato. As the potatoes enlarge, they will tend to rise above the soil level. The tubers must be protected from sunlight or they will become sunburned. Sunburned potatoes turn green and produce a toxic chemical called solanine. Hilling prevents potato greening.
Hill your potatoes by pulling more dirt or mulch up over the tubers. By applying a thick layer of mulch when the plants are 8 to 10 inches tall, you will block sunlight, reduce soil temperature, and increase yield and quality. The last hilling should be done before the potato plants bloom, when the plant is about 6 inches tall. Hoe the dirt up around the base of the plant in order to cover the tubers as well as to support the plant.
Potato plants will display beautiful white, lavender or purple flowers and sometimes will even produce fruits. The fruits bear the true seed of the potato plant. They look like small tomatoes but they're not edible.
Fertilize when the plants are about 4 to 6 inches tall.
Try to keep the moisture supply constant. They should be moist but not wet. Too much water enlarges the pores on the tubers and makes them rot easily in storage. This is especially critical during the period between when sprouts first appear until several weeks after they blossom. During this time, the plants need 1 to 2 inches of water per week. If you water too much right after planting and not enough as the potatoes begin to form, the tubers can become misshapen.
Weeds steal nutrients and moisture from your plants. Gently pull weeds or spray them with our 20% vinegar and orange oil weed killing recipe. The vinegar will also help to acidify the soil, which will benefit your potatoes.
Pests And Diseases
Potatoes are susceptible to several soil borne diseases such as potato blight and potato scab.
Blight is a fungus that causes potatoes to rot in the ground. There are several things you can do to prevent blight from getting started.
Where possible, rotate your crops. This is a good practice to follow for all annual vegetables and even flowers. Rotation prevents the build up of fungal spores and bacteria in the soil and helps ensure than any remaining infected plant pieces have fully composted into the soil.
When watering, try to keep it off the foliage. Of course, some water invariably will get on the leaves anyway, so water in the morning to allow time for any moisture on the leaves to evaporate during the day. Again, this practice will benefit all your other plants as well.
Blight is most likely to get started when the weather is warm and humid. You can help prevent it from developing by dusting your seed potatoes with sulfur before planting. After planting, you can spray your potatoes with a quality organic fungicide. Some good choices are Neem Oil, Fertilome Triple Action, or Spinosad.
Finally, when you harvest your crop, make sure you dig up every last potato so blight has nowhere to hide during the winter.
Potato Scab is caused by a high soil pH. Remember, potatoes like acidic soil (low pH). Do not plant your crop in soil with a pH higher than 5.2.
One of the potato’s most common pests is the Colorado potato beetle. The best way to deal with these is to hand pick them. Better still, let the birds eat them. While they’re in the nymph state, they can be controlled with Diatomaceous Earth (food grade) which is a non-toxic way to control pests in the garden. If they continue to be a problem, a few sprays of Spinosad, an organic pesticide, will get rid of the beetles. Always use pesticides — even organic ones — at dawn or dusk to avoid harming beneficial insects.
Aphids are easily controlled by releasing beneficial insects — either Praying Mantises or Ladybugs. You can also use Insecticidal Soap or Neem Oil. Always be careful not to spray in the middle of the day (10a.m. to 5p.m.) when bees are active.
Harvesting and Curing
Potatoes need to be cured a second time before they can be harvested. This process needs to begin about 2 weeks before you dig them up. At this point you should severely cut back on watering. The drying process will help toughen the potato skins. During this period, the top growth will begin to slowly die. Wait until the tops are completely dead. They should be dried up and brown.
If you are uncertain about whether your crop is ready, you can do a test dig to dig up one of the potatoes and inspect it.
Carefully dig them up with a fork. Try to avoid scraping or piercing the potato. After you harvest them, you will need to continue curing them to further toughen up the skin.
After you’ve dug them up, clean them, again being careful not to damage the skin.
NOTE: Don’t store potatoes with apples or fruits that give off ethylene gas, as this may cause them to sprout.
Place them in a well-ventilated container and stored in a dry location, away from sunlight, and at temperatures between 45 and 55 degrees F for about 10 days. For most of us, finding a spot that meets those requirements may be problematic. Another easier option to place them in a paper bag or cardboard box (not in a plastic bag) and keep them in the coolest part of the kitchen or a dry part of your basement.
After they’ve cured, check them for damage. Toss any that have soft spots, green ends or open cuts. Then you can move them into longer term storage.
Refrigerating them works well but tends to increase their sweetness and causes them to brown very quickly when fried. Not to mention that your crop may be too large to store in your fridge. An unheated basement or garage is also a good choice. Don’t store tubers where temperatures are likely to freeze, as they will crack open.
How long they will ultimately keep depends on a number of factors. For example, red potatoes do not keep as long as the white or yellow skinned varieties. Thick skinned russets have an even longer life. Use the thinner skinned spuds first.