Stephen Brueggerhoff, CEA – Horticulture, Brazos County AgriLife Extension; published 2/017/2026

All images unless otherwise noted by Stephen Brueggerhoff

Potatoes and onions go together like peas in a pod, veggies that are often cooked together and are a staple in the Brueggerhoff household. These veggies are also cultivated and harvested around the same time, each with their own unique origins and growing habits.

Global Travelers

Modern potatoes originate in South America along the Andes, from coastal Chile to Argentina, Bolivia and Peru and estimated to arrive in Europe in the 1500s. Commercial Texas production includes the High Plains (Panhandle), the Rolling Plains, the Winter Garden (generally north of Laredo and south of San Antonio); and the Rio Grande Valley. Bulb onions (Allium cepa) have been domesticated over centuries and originate from central Asia. Historically, members from the Columbus expeditions cultivated bulb onions in Hispaniola as early as 1494, introducing a commodity that became well established as a staple in North America by the nineteenth century.

The Eyes Have It: Potato Cultivation

Potatoes are starchy tubers with vegetative buds (eyes) that produce above-ground leafy stems and eventually form tubers at the tips of root structures. The tubers we use for planting are called seed potatoes that have been cured and stored from previous years’ harvest. Irish potatoes are the tubers appropriate for cultivating in our area and include varietals like red flesh Norland, La Soda and Viking, white Kennebec and Superior, and popular yellow flesh Yukon Gold.

Choose well-formed seedlings three to four inches in length, about the size of a large hen’s egg. You can cut larger seedlings into quarters or half depending on their size and make you have at least one good eye on these new seed pieces. If cut, dry for several days in a well-ventilated room, allowing the pieces to scab over and seal the large wound. You can pretreat these pieces with dusting sulfur applied by coating pieces in a paper lunch bag. Wear a mask, gloves and old clothes. Sulfur will stain clothes, can irritate your respiratory system, some may have an allergic reaction to the dust, and keep in mind that slightly rotten egg smell will linger in the room. You may not have time to chit your potatoes, which is the process of sprouting about 4 weeks before planting. Chitting potatoes gives them a shorter growing time in the soil for potentially heavier yield.

To plant, prepare a well-draining, enriched bed forming 12-inch-high berms. Flatten the berms to 8-inches and 12-inches wide. Prep the planting site with a band of fertilizer in 4-inch-deep trenches and on each side of the row. Apply 2 cups in each trench per 30-foot row. Create a 3-inch-deep trench down the middle of the row and space seedlings 12-inches apart, cover and water in the rows. We don’t want to plant the seed pieces too deep as they have the potential to rot. The seed potato will develop new tubers along the stem below ground and above the seed potato. You will be pulling up soil along the sides of the row as the emerging stems elongate. Apply 3 tablespoons of fertilizer per 10 feet of row alongside when the plants are about four inches tall. The basic rule of thumb for watering is maintaining adequate moisture but not oversaturating the soil. Harvest time relies on visual cues from the plant; once the above-ground plant begins to die, it is time to harvest and on average about 100 days from planting. To dig out, use a spading fork and aim for about ten inches away from the plant to prevent damaging the spuds. Push down the fork and lever up the soil. Shake away soil from the tubers but don’t hose them down. We want them to dry and harden their skin first before dusting off excess soil. Store in a cool, well-ventilated room such as a bench in your garage or in a dark pantry.

Don’t Cry Now: Bulb Onion Cultivation

The onion bulb is a storage organ for the plant. The bulb produces a fan of hollow, blue-green leaves that facilitate photosynthesis. Each leaf is associated with the inner ring of the bulb, so when you laterally cut open an onion you see rings that are made of fleshy modified leaves. Bulb onions enlarge and form in response to specific day length and temperature, identified as long and short-day onions. Onions have a habit of bolting when ambient temps become too hot, and for our region it is best to transplant short day varieties like yellow 1015 Texas Supersweet, Sakata Red, Yellow Granex or Texas Early White that require up to twelve daylight hours for production in fall or late winter. Each can take up to 110 days to harvest.

The starts are purchased in a gathered bunch of around 30 to 40 plants. Transplant with full sun exposure in well-draining soil in beds raised 6 to 10-inches high. Bed prep should include 3 pounds of fertilizer over 100 square feet of garden area mixed within the top 3-inches of soil. Plant at 3/4 –inch deep at 3-inches apart. Cultivation includes keeping the garden bed free of weeds that will compete for natural resources and impact the size of the developing bulb. Apply another round of fertilizer when the plants form 6 leaves, about 1/2 cup for each 10-feet of row, spread evenly between the rows and water in the product. Water evenly and as the soil begins to dry. Harvest when the leaves begin to fall over, then leave in the garden to dry for up to two days. Remove the tops and roots and allow them to continue to dry and paper up in well-ventilated boxes. You can then store the cured onion bulbs in your refrigerator crisper or in a wire or ventilated mesh bag in a cool garage or utility room.

Growing these veggies can be a rewarding experience, patience is key to cultivation and conserve water resources in any gardening endeavor. Keep conserving natural resources while growing your veggies and I will see you in the garden.