By the time May rolls around in Central Texas’ edible gardens, most of the heat-loving crops have been planted and we are tending to watering, pest control and harvesting many of those fruits and veggies that were planted in March and April.
In May, there are a few crops that can still be planted from seed like okra, melons and Southern peas. Sweet potatoes also can be planted now, and they love our hot summer weather. The best varieties for growing in Central Texas are Beauregard, centennial and jewel.
The method for planting and growing them is unique, and the reward of a treasure huntlike harvest can make a new gardener feel very accomplished.
Before we get into the how-to of growing your own sweet potatoes, let’s dig a little deeper into the origins of the sweet potato.
The sweet potato is one of the most widely grown and important root crops in the world. Scientists believe sweet potatoes were cultivated more than 5,000 years ago in Central and South America, and there is evidence that other related plants in the morning glory family (Convolvulaceae family) might have originated in the Old World millions of years ago.
The sweet potato is a very distant relative of the white potato, which is in the Solanaceae or night-shade family. It is also botanically distinct from a yam (Dioscoreaceae family) although there has been some confusion over those names possibly due to an agricultural marketing campaign to differentiate white, hard sweet potatoes from the soft, orange-flesh ones. Yams are native to Africa and Asia and have barklike skin.
The preferred way to grow sweet potatoes in a home garden is to purchase or grow your own “slips.” These are transplants that are grown from a mature sweet potato. Most nurseries will carry sweet potato slips that are ready to be planted outside, but you can start your own on a windowsill inside.
The time frame for planting your slips into the garden in Central Texas is April through the end of June. Make sure you start growing your slips right away so you have time to transplant them outside before the end of June.
To make slips, purchase an organic sweet potato from the grocery store then submerge half the sweet potato in a jar filled with water using toothpicks to hold the sweet potato in place. Put the jar in a sunny window and add water every few days to keep the jar full.
In two to three weeks, you will see stems and leaves emerge from the potato with roots growing in the water. These are your slips. Once the slips have grown to about 6 inches, break them off the mature potato and place the slips’ roots in a new jar of fresh water. You can add 1 teaspoon of coffee grounds to the water at this time for a little boost of nitrogen. The slips will grow stronger roots for a couple more weeks.
When it’s time to plant the slips outside in the garden, remember that potatoes need loose, well-drained soil to grow large tubers underground. Creating mounds of loose soil where you will plant the slips will give a lot of space below.
Dig a hole about 5 inches deep and 3 inches wide or large enough to cover all the roots. Leave the stem and leaves above ground and gently cover the roots.
Keep the soil well-watered for the first week and then consistently watered thereafter.
Sweet potatoes can withstand drought and are not pest-prone, which makes them great to grow here in the hot, dry summer. However, with consistent water, the plants will produce more tubers.
Sweet potatoes grow from vines, so this vigorous plant will begin to creep all around the garden. It is a very pretty plant, and the leaves are edible too, but as it grows it might seem to become invasive, so give it lots of space to crawl.
Plants require 110 days to 140 days from planting to maturity, and because your crop is growing underground, you will need to mark this time on your calendar to know when to harvest. There are also some telling signs on the leaves above ground when it is time to harvest. Once the leaves start turning yellow and the vines slow their growth, you can carefully unearth your buried treasure.
If you spear or nick potatoes when harvesting, cook those immediately because they will not store well. Allow the unblemished potatoes to dry outside in the shade for a week then brush off the soil and store them in a shady place with good airflow. Don’t wash them until you are ready to cook with them. They can store for many months if cured properly.
This month’s recipe is from Maite Aizpurua, the chef behind the Mighty Spoon. Aizpurua has spent time working in restaurants in New York City and the Basque region of Spain.
In Austin, she has worked in the kitchen at Odd Duck and Sour Duck Market, started a bone broth brand and created oyster pop-ups at Hotel San Jose.
Now, she offers pop-up experiences of all kinds, food photography, recipe development and virtual classes where she focuses on helping people master an innate understanding of ingredients, flavors and techniques.
Sweet Potato Miso Dressing
1 inch ginger
1 clove garlic
2 tablespoons miso
1/4 teaspoon salt
1/2 cup sweet potato, cooked
5 tablespoons vinegar
3 tablespoons water
8 tablespoons extra virgin olive oil
2 tablespoons sesame oil
Blend all ingredients until smooth. For a more refined finish, pass the dressing through a sieve after blending. Use on top of your favorite salads right away or keep in an airtight container in the refrigerator for up to a week.
Makes about 1 cup.
Liz Cardinal is the founder of Austin Edible Gardens, austinediblegardens.com.