One of my New Year’s Resolutions is to start a vegetable garden. When can I start to plant? AG

Even though we just recently crossed over into 2021, we are a little over a month away from beginning to start some of our cool season vegetables. Some of these can be started from seed while you’ll have better success with others if you start them outdoors as plants. Let’s break it down a bit.

There are several plants you can start outside around mid-March: broccoli, cabbage, cauliflower, lettuce, and onions. If you want to plant these mid-March, you will need to either find plants at a garden store or start your seeds indoors before then. However, many gardeners know vegetable starts can be challenging to find at the beginning of March so you may want to think about starting seeds indoors.

Vegetables that can be started from seed and then planted outdoors mid-March include beets, carrots, swiss chard, kohlrabi, lettuce, peas, radishes, spinach, and turnips.

Typically, your seeds are going to need 5-6 weeks indoors before they are ready to move outdoors. So, if your target to plant a cool season is mid-March, then we need to have our seeds ready to start germinating by the first of February. Personally, I like to grow my vegetables from seeds which means I need to get busy!

Starting seeds indoors can be a lot of fun for adults as well as for kids. There are a variety of products you can utilize depending on how deep you want to dive into this. In the most basic of set ups, you just need some seed starting soil, seeds, containers, water, and a bright warm room.

Once you get your seeds, you will need to decide what type of temporary container you are going to plant them in. You can purchase seed trays at the garden store or empty yogurt containers are also a good choice. Anything that is small and manageable enough will work. Personally, I like to use the seed trays and the peat pots since the peat pots can be planted in the ground when the time comes. With this method you have less potential for damaging your little transplants when planting, but that is just me.

Once you have your container, you will need some sort of growing medium. Seed starting soil is a good choice because it has a really fine consistency that enables the roots young roots to grow. These seed starting soils can come with a little fertilizer in them, but once your plants begin to grow, you should plan on adding fertilizer.

A lot of seeds for the crops we are going to want to grow will germinate quickest in soil that is about 70 degrees. Many of us have seed trays and seed heating mats to make sure our soil reaches this temperature to help speed up the germination process, but it’s not necessary. Just know that germination time with a seed heating mat can be a couple of days while without, it might be a couple of weeks.

These seed starting trays also come with clear plastic covers. These help maintain a warm moist environment. But once your seeds have germinated and are starting to grow, the cover needs to come off and the heating mat needs to be turned off because those warm, moist environments can become perfect breeding grounds for fungi.

Next you job is to nurture your new little ones until they are ready and weather conditions are appropriate to plant outdoors. If your plants get long and lanky, this is an indicator that they probably don’t have enough light. This is not a fatal error, and in my experience, this can correct itself once they are planted outdoors. But good light is key.

Speaking of light. If you budget allows, there are nice, suspended grow lights with frames that are adjustable. By adjustable, I mean they have cords which allow the light bulbs to be raised as your baby plants grow. If you have access to these, start the lights out down low near the top of your container covers. As your plants grow, raise up the lights to allow for growth. You may also need to rotate your plants so that they equally share in the light. If you don’t, you will likely have tall ones right under the light and shorter ones near the edges.

Once the seedlings begin to get established, some gardeners like to move them to larger individual containers full of a rich garden soil mix. The advantage to this is that the roots will be able to expand more than they would if they were still contained in the smaller seed-starting pots. But, this is not a necessity.

And last, but certainly not least, you will need to harden off your new plants before planting them outdoors. Hardening off is the practice of letting them get adjusted to outside life gradually, rather than just plopping them in the ground in full sun.

Plan on about a week of hardening off, which means you should find a partly shaded spot outdoors for your plants to let them gradually get used to the sun and wind. After a few days of this, they will be acclimated and ready to go in the ground.

You can get answers to all your gardening questions by calling the Tulsa Master Gardeners Help Line at 918-746-3701, dropping by our Diagnostic Center at 4116 E. 15th Street, or by emailing us at mg@tulsamastergardeners.org.