Onions

Plant in rich soil for big, beautiful onions!

An onion set is a bunch of small onion bulbs, planted instead of seed.

In Central Texas, bulbing onions can be planted October – February.  Timing is critical, and in Central Texas we have the most success with short-day onions.  Onion plants are sensitive to both day length and temperature. If sets are planted in the fall, or if seeds are planted too early, they will likely bolt the next spring. Bolting means the onion will form a flower, which reduces size and density of the bulb, and makes it more prone to decay. Planting seeds too late may lead to immature plants which require extra protection from winter freezes.

  • plant seed October-December
  • plant sets January-February

We typically bring onion sets in at the beginning of January.  When you purchase your onion set, keep them in a cool, dry area.  DO NOT put them in water or soil while waiting to plant.  The plants are in a dormant state, and should be planted as soon as possible.  The roots and tops may begin to dry out, but don’t be alarmed—as a member of the lily family, the onion can live for three weeks off of the bulb.

Southern Belle Red
110 days to maturity

  • Up to 4″ diameter bulbs
  • A hybrid, globe-shaped, sweet red onion
  • May store up to 2 months
  • Bolt resistant

Texas Legend
105 days to maturity

  • Up to 6″ diameter bulbs
  • Open-pollinated
  • Globe-shaped, sweet yellow onion
  • May store for 3-4 months

Yellow Granex
100 days to maturity

  • Up to 5″ diameter bulbs
  • A hybrid with semi-flat shape and rounded shoulders
  • Sweet yellow onion
  • May store for 1 month
  • Also known as the Vidalia onion when it is grown in southern Georgia.

1015Y Texas Supersweet
115 days to maturity

  • Up to 6″ diameter bulbs
  • Open-pollinated
  • Very sweet and mild globe-shaped onion
  • May store up for 2-3 months
  • Name comes from the date the seeds should be planted (Oct 15).

Texas Early White
110 days to maturity

  • Up to 5-6″ diameter bulbs
  • Open-pollinated
  • Globe-shaped, sweet white onion
  • May store for 2-3 months
  • Disease and bolt resistant

White Bermuda
95 days to maturity

  • Up to 3-4″ diameter bulbs
  • Open-pollinated
  • Sweet and mild, white, flat onion
  • May store for 2 months
  • Also known as the Crystal Wax variety

Along with timing, the key to big beautiful onions is rich soil. Every ring of the onion is a leaf of the plant, so regular feeding with organic fertilizer is important. To plant, choose a location in full sun. To prepare existing soil for onions in the ground, mix in one of our quality composts. The resulting blend should be about 50:50 compost and soil. At the same time, mix in an:

  • organic high phosphorus fertilizer,
  • mycorrhizal fungi,
  • and a mineral supplement.
  • Consider adding organic controls (such as streptomyces) to prevent fungal diseases that effect onions.
  • Adding soil sulfur to the soil will help to slightly lower the pH.

If you have shallow soil or poor drainage, make a raised bed for your onions. Use a prepared potting soil, and add all of the amendments listed above.

If you are planting onion seeds, you may scatter them densely, but be sure to thin out the little green onions to 4” apart by February to get bigger bulbs.  Onion sets should be planted one inch deep and four inches apart, or plant two inches apart and harvest every other one as a green onion.

  • Water thoroughly after planting with a seaweed solution.  Seaweed may be used once or twice a month to strengthen the plants.
  • Fertilize every 4 weeks after planting with an organic, high nitrogen fertilizer to produce more leaves and bigger bulbs.  When the ground starts to crack as the onions push the soil away, the bulbing process has begun. Stop fertilizing at this point.
  • Water the onions regularly and deeply to keep the soil moist, but not soggy.
  • Add about three inches of mulch to help keep soil moist and to control weeds.

When the tops of the onions turn brown or yellow and fall over, it’s time to harvest.  Ideally, the plant will have about 13 leaves at this point.  Pull the onions early in the morning on a sunny day.  Dry the onions in the sun for two to three days.  To prevent sunscald, lay the tops of one row over the bulbs of another.

How long your onions will keep depends on how you treat them after harvest.  They must be dried thoroughly to avoid problems with rot.  If left outside when the weather is dry, this will take two or three days.  The entire neck (where the leaves meet the bulb) should be dry, all the way to the surface of the onion.  The skin will take on a uniform texture and color.  If rain is expected, you’ll need to dry your onions indoors.  Spread them out in a well-ventilated area with room to breath.  Drying indoors may take longer than outdoors.

Once the onions are thoroughly dry, clip the roots and cut back the tops to one inch.  Now they are ready to eat!