Texas gardeners enjoy mild spring and autumn weather. During December, however, the state experiences temperatures that dip below freezing. Northern portions of the state even experience snow. These temperatures and icy conditions make it impossible to grow vegetables outdoors. Instead, plant vegetables inside during December and leave them indoors until temperatures start to warm up in February or March.
Check your containers for drainage holes. Vegetable seeds and seedlings need well-drained soil; without drainage, the plants' roots may develop root rot due to too-wet conditions. This is especially important along the Texas Gulf Coast, where the high humidity makes it more difficult for excess water to evaporate.
If your containers do not have holes, use a 1/2-inch drill bit to drill at least one hole in the bottom of each container. Use a masonry bit for clay or pottery containers.
Fill each of the containers with potting mix. Use a watering can or pitcher to mix in just enough water to make the soil moist.
Create a well in the center of the soil's surface and plant the seeds or seedlings. If you are planting seeds, plant three seeds in the center, within an inch or two of one another. Once the seeds develop their first set of leaves, pull out the weaker two seedlings, and leave only the strongest one to develop into a plant. If you are planting seedlings instead of seeds, plant one per container.
Insert stakes into the outer edges of the pots to give support to vining or top-heavy plants (such as tomatoes). Lash the stakes to one another with twine, to give the stakes and plants more stability.
Place the containers near a window in your home that receives at least eight hours of sunlight during the day. In Northern Texas, where snow storms are common during December, place the containers near double-paned or insulated windows, to keep seedlings from getting chilled.
Feed the plants with all-purpose plant feed after the seeds germinate. Dilute the fertilizer to half of the directed strength until the plants have developed two sets of leaves. After that, use the recommended strength.
Use a watering can or pitcher to water the plants regularly. Keep the soil moist but not wet. The frequency of watering depends on several factors: indoor humidity, the amount that each plant drinks, indoor temperatures, and the size of the container. For best results, check the soil in each of the plants every day or every other day and water accordingly.
Use insecticidal soap to control indoor plant pests as needed. White flies and gnats are common plant invaders in humid conditions. EdibleContainerGardening.com recommends using a homemade insecticidal soap made with organic ingredients to control pests while keeping the vegetables safe for consumption.