Winter Seed Starting Tips
Curious about starting seeds for your winter crop? If you missed our Seed Starting Workshop with professional urban farmer, Idzai Mubaiwa, don’t worry! We took notes to share, so you can start your own seeds at home.
So, What Is Seed Starting?
Seed starting is just what it sounds like, it’s the process of growing plants from seed. There are many great reasons to start plants from seed. First of all, it’s thrifty. Purchasing transplants can get pricey, especially when attempting to fill your entire raised bed plot. For the same cost of one transplant, you can purchase a seed packet with dozens of seeds. Then, of course, there’s the less-quantifiable joy of growing something from start to finish—getting to see your once-little sprout blossom into a mature plant.
There are two ways you can start your seeds:
In Ground: For this method, you plant seeds directly into the ground. This is best for plants that grow underground, like beets, radishes, and carrots. These plants tend to be sensitive to transplanting.
In Containers: For this method, you plant seeds in small containers like egg cartons, and then transplant them once they’ve developed into larger seedlings.
When Should You Start Winter Seeds?
The best time to start winter seeds in San Diego is between late August and early October. This ensures your plants have the time and sun required to grow enough before the cold season sets in. If they’re still small seedlings when soil temperatures decline, your plants are less likely to survive.
Best Seeds to Start for Winter
Lettuce
Kale
Swiss Chard
Bok Choi
Celery
Calendula
Peas
Cabbage
Cauliflower
Beets
Radishes
Spinach
Kohlrabi
Pansies
Snapdragons
Stock (Matthiola Incana)
How to Start Winter Seeds in Containers
Step 1: Choose the right container.
Too large a container can be cumbersome when you need to transfer your seedlings into the ground. A smaller container means you won’t need to dig up your seedlings to put them in the ground, causing less stress to your seedlings. Egg cartons make ideal seed start containers, especially if you’re looking to avoid plastic (or buying something new). If you’d like to start a large amount of seeds, opt for a seed starting tray. You can find a variety of these at City Farmers Nursery!
Step 2: Add your soil mix.
You can opt for purchasing seed starting mix, but you can also create your own soil mix pretty easily. All you need is your standard potting soil and (if you really want happy seedlings) a sprinkling of worm castings, or vermiculture compost. You can typically find that in our gardener shed, thanks to the gardeners on the Compost Team and our hardworking worms! Here’s what to do next:
Mix your soil and castings together.
Work the soil with your hands, breaking up any clumps so it’s nice and fine.
Add just enough soil to be about level with the top of the container. No need to heap it on.
Step 3: Add your seeds.
You don’t need bury your seeds deep in the soil. In fact, burying them can make it hard for them to sprout. Instead, simply press them slightly into the soil, and cover them up with a dusting of soil. You can add 1 to 3 seeds per hole in your container, depending on the size of the seed and hole.
Step 4: Add water.
Okay, this part’s important. Don’t overwater your seeds. Just saturate the soil using a watering can or spray bottle. Don’t water it again until the soil is dry. Overwatering can result in mildew or damage the seed, causing it to not sprout.
Step 5: Set it in the right spot.
To germinate the seed (meaning, to get it to sprout), you don’t need much (or any) light for most seeds. At this stage, it’s less about light and more about soil temperature. So set your seed starts in a spot where you can ensure the soil is getting warmed by indirect light.
Step 6: Patience, my friend.
All you have to do is wait and water again when your soil gets dry! How long a seed takes to sprout depends on the seed. The estimated sprout time is typically listed on the seed packet. It can take anywhere from 3 days to 10 days. If it’s gone beyond a couple weeks, your seeds are likely not going to sprout. It may be a good idea to check if they were beyond their expiration date.
Tips From A Pro
Host Idzai Mubaiwa answering questions during our Q&A.
Idzai had us ooo-ing and ahh-ing with these seed-starting hacks.
Sprinkle Cinnamon on Your Soil Surface: Just a light dusting of cinnamon can help prevent the build up of mildew.
Cover Your Seed Starts: Idzai recommends using farm cloths (sheets that are black on one side, white on the other) to cover your seeds, just until they sprout. The coverage results in precipitation that keeps your soil moist, and increases the speed to sprout. Put the white side of the sheet facing up, so the black side is facing the soil. Check on the seeds daily. Once you notice your first sprout pop up, remove the cover.
Test Your Seeds: If your seeds are a bit old, you can test a few to see if they’re still viable. This process is easy and will save you the time and effort of trying to start bad seeds. All you have to do is place a few seeds on a moist paper towel, and fold the towel over to cover the seeds. Place the folded towel into a ziplock bag, seal it, and set it in a shaded area away from the sun. Check daily to see if they germinate. If you don’t get sprouts, your seeds are likely no longer viable.
Attend Our Next Seed Starting Workshop
This event was such a hit, we’ve asked Idzai to return seasonally to walk us through seed starting for spring, summer, fall, and winter plants. So if you missed this one, you’ll get another chance to ask questions and take part in a farm-fresh feast! Keep an eye on our events page for the next workshop, coming this winter.
