When To Plant 1015 Onions In Texas

If you’re a Texas gardener, knowing when to plant 1015 onions is the first step to a huge harvest. This sweet, Texas-born variety thrives when you get the timing just right, and this guide will walk you through the optimal planting season for your region.

Named for its ideal planting date of October 15th, the 1015Y Texas SuperSweet onion is a staple. But Texas is a big state with diverse climates, so that date is more of a starting point. Planting at the correct time allows the onion to establish roots in cool weather and form big bulbs as days lengthen in spring.

This is your core calendar. For most of Texas, the planting window for 1015 onion sets or plants is from early October through mid-December. The goal is to get them in the ground so they develop a strong root system before the coldest winter weather hits, but after the soil has cooled down from summer’s heat.

Regional Planting Dates Across Texas

Because Texas spans several climate zones, you’ll need to adjust your schedule. Here’s a breakdown by major region:

North Texas & Panhandle: Plant from mid-October to early November. Early freezes are common, so getting them established before a hard freeze is key.
Central Texas (including Austin/San Antonio): The classic “October 15th” target works well here. The window typically runs from early October to mid-November.
South Texas & Coastal Bend: You can plant later, from late November through December. The milder winters allow for a more flexible schedule.
West Texas: Aim for early to mid-October. The arid climate and temperature swings make timely planting extra important for root development.

Why Timing is Everything for 1015 Onions

Onions are photoperiodic, meaning bulb formation is triggered by day length. The 1015 is a short-day onion, which bulbs up when daylight lasts 10-12 hours. If you plant too late in the winter, the plant won’t have enough green growth (tops) to support a large bulb when the triggering day length arrives. If you plant to early while soil is still warm, you risk premature bolting (flowering).

Signs You’re Planting at the Right Time

Soil temperature is below 85°F.
Daytime highs are consistently in the 70s or 80s.
You have 4-6 weeks of growing time before your first average hard freeze.

Preparing Your Garden Bed

Onions need loose, well-draining soil and plenty of nutrients. Here’s how to get your bed ready:

Choose a Sunny Spot: Select a location that gets full sun—at least 6-8 hours of direct light daily.
Loosen the Soil: Till or dig the soil to a depth of about 8-10 inches. Onions struggle in heavy, compacted clay.
Amend the Soil: Mix in 2-3 inches of compost or well-rotted manure. This improves drainage and fertility.
Check the pH: Onions prefer a soil pH between 6.0 and 6.8. A simple soil test can tell you if you need to add lime (to raise pH) or sulfur (to lower it).
Add Fertilizer: Work a balanced fertilizer (like 10-10-10) or one higher in phosphorus (the middle number) into the soil before planting to encourage strong root growth.

Step-by-Step Planting Guide

You can start 1015 onions from seed, sets (small bulbs), or transplants (small plants). For most gardeners, transplants or sets are easiest and ensure a harvest in the same season.

Source Your Plants: Buy fresh, healthy onion sets or transplants from a local nursery or reputable online source. Look for stems about the diameter of a pencil.
Plant Correctly: Space plants about 4 inches apart in rows that are 12-15 inches apart. If using sets, plant them just deep enough so the tip is level with the soil surface. For transplants, plant them so the white base is about 1 inch deep.
Water Thoroughly: Give them a good, deep watering immediately after planting to settle the soil around the roots.
Apply Mulch: A 1-2 inch layer of straw or shredded leaves helps retain moisture, suppress weeds, and moderate soil temperature.

Caring for Your Onions Through the Season

Consistent care is simple but crucial for developing those sweet, juicy bulbs.

Watering and Feeding

Onions have shallow roots and need consistent moisture. Water deeply when the top inch of soil feels dry, usually about 1 inch of water per week. Reduce watering as the bulbs begin to mature and the tops start to yellow and fall over.

Feed your onions every 3-4 weeks with a nitrogen fertilizer, like a 21-0-0 side dressing, until the bulbs begin to swell. Stop fertilizing once the bulbs start to form, as too much nitrogen then can hurt storage quality.

Weeding and Maintenance

Weeds compete fiercely with onions for nutrients. Hand-pull weeds carefully to avoid disturbing the onion’s shallow roots. The mulch you applied will do most of the work for you. Keep an eye out for pests like thrips, which can be treated with insecticidal soap if they become a problem.

Harvesting and Curing Your 1015 Onions

Your onions are ready for harvest in late spring, typically April or May in most of Texas. The tops will turn yellow and begin to topple over. When about half the tops have fallen, it’s time to harvest.

Gently loosen the soil with a fork and lift the bulbs.
Brush off excess soil, but do not wash them.
Cure for Storage: Lay them in a single layer in a warm, dry, well-ventilated place out of direct sun for 2-3 weeks. This allows the outer layers to dry and the necks to seal, which is essential for long-term storage.
Once the necks are tight and the outer skins are papery, trim the roots and cut the tops back to about 1 inch. Store in a cool, dry, dark place in mesh bags or a single layer.

Common Problems and Solutions

Bulbs Not Forming: Usually caused by planting too late, overcrowding, or insufficient sunlight.
Premature Bolting: Often triggered by planting too early when soil is still warm, or a sudden cold snap followed by warm weather. Remove the flower stalk and use that onion first.
Small Bulbs: Can result from poor soil, lack of water, or not enough fertilizer during the growing stage.
Rotting in Ground: Caused by poorly draining soil or to much water near harvest time. Ensure your bed is well-drained.

Frequently Asked Questions (FAQ)

Can I plant 1015 onions in the spring in Texas?

It’s not recommended. Spring-planted 1015 onions won’t experience the cool growth period they need and will likely form very small bulbs or bolt immediately as days get longer.

What is the best month to plant onions in Texas?

For 1015 onions, October and November are the prime months for most of the state. Adjust slightly earlier for north and west regions, and slightly later for south Texas.

How long does it take for 1015 onions to grow?

From transplanting in fall, they take roughly 180-200 days to reach full maturity for harvest in late spring. They are a long-season crop that requires patience.

Can I grow 1015 onions from grocery store onions?

It’s not reliable. Store-bought onions are often treated to prevent sprouting and may not be adapted to your local climate. It’s best to buy certified disease-free sets or transplants.

Do 1015 onions need a lot of water?

They need consistent moisture, especially during bulb formation. However, soggy soil will cause rot. The key is deep, infrequent watering to encourage strong root growth.

Following this guide for when to plant 1015 onions in Texas will set you up for success. By paying close attention to your local frost dates and regional climate, preparing your soil well, and providing simple consistent care, you’ll be rewarded with a bountiful harvest of sweet, homegrown onions that are worth the wait. Remember, getting them in the ground at the optimal time this fall is the most important step you can take.