Here in Iowa its 10 below and everything has been frozen for a week now. Its times like this that April can seem so far away. But January is an important month for us, as its when we do much of the planning and initial prep-work for our market garden. Plots and crop rotation are mapped out on graph paper, seeds are ordered, and here very soon we’ll be starting our first round of transplants under grow lights.
Transplants are an important part of our planting scheme. Many of our crops are grown from putting seed right in the ground. Our corn, beans, squash and the majority of our leaf and root crops are all done this way. But there are certain crops that we always start indoors and then transplant when the ground is warmer. This is where taking the time for proper planning is important. Knowing our planting season, relative last frost, varieties we want to plant and their maturity time frame are crucial.
So why transplant? Good question. Many crops can be started indoors under grow lights rather than by direct seeding. The advantages to this are multifaceted but include stronger disease resistance, protection against late frost or other weather events, protection against birds or other animals that like to dig up seed, and getting a jump on long maturity dates. Not to mention that it’s fun to start seeds indoors when there is snow on the ground.
Certain plants should always be started indoors, or bought as transplants from your local nursery or greenhouse. Here are six vegetables that you’ll have a higher success growing if you transplant rather than direct seed.
Tomatoes are somewhat fickle when they are first starting out. They’re not hard to grow, but exposing them to the elements through direct seeding doesn’t usually have good and consistent results. Tomato seeds are very small. They need the right temperature and amount of moisture to germinate. Most varieties of determinate and indeterminate tomatoes also have long days to maturity, meaning that if you wait until outdoor conditions are right for sowing your seed, you probably wont’ be picking those juicy red slicers in time for burgers and bbq.
For our market, we need to have fresh tomatoes as soon as possible.
In order for tomato seeds to germinate, your soil temperature needs to be around 70 degrees. They’ll need a steady source of light until they sprout, which means you don’t want to plant them too deep. We plant ours at about 1/4 and lightly cover with soil. The soil should be kept moist, but not saturated or the seed can rot. Once your seeds sprout and start to grow you’ll want to keep them under direct light for at least 8 hours a day.
Start your seeds no later than 4-6 weeks before the last frost in your area. We start ours around 8 weeks before last frost because I like to have a little more stem height when I go to transplant. This allows me to bury the stem nice and deep to ensure strong root development.
Peppers are part of the Solanaceae (Nightshade) family, like their cousin the tomato. Also like tomatoes, they aren’t difficult to start from seed but getting consistent germination can be frustrating with certain varieties.
We plant our pepper seeds just like we do our tomatoes, but we’ll start them at least 8-10 weeks before the last frost as they take longer to grow, sometimes earlier depending on the variety. Hot peppers like habanero can sometimes be fickle, but they’re the most profitable for us at the market. So these we take our time getting right.
You’ll want consistent moisture and soil temps around 70-80 degrees. I’ve found that sometimes an overhead light isn’t enough to get good germination. We start our seeds in Jiffy Peat Pods underneath a hard plastic cover, which creates a kind of extra greenhouse effect under the lights, trapping in the moisture and heat. You can also try a heated pad underneath your seed tray, but we don’t use that method. Once the seeds sprout, we remove the plastic cover and let expose the seedlings to 8 hours of light each day, always checking the soil moisture content.
We start our broccoli indoors around 7 weeks before last frost. In some climates, broccoli can be direct seeded, but we’ve found that our broccoli is much more healthy and better developed when we transplant. One of the biggest factors for us is pest penetration. Flea beetles love to eat young broccoli seedlings as they emerge, often decimating a whole crop overnight. Deer like to munch on broccoli too. Transplanting doesn’t guarantee either of these pests won’t go after your crop, but a bigger, stronger plant has a much better chance at surviving insect (or deer) infestation than seedlings.
Broccoli will germinate in soil temps as low as 45 degrees, and will usually only take 4-7 days. Broccoli thrives in cooler weather, but make sure temps are consistently above 55 before you transplant or else you might have early bolting (your broccoli head flowering and going to seed).
We handle cabbage and cauliflower the same as we do broccoli. All three are part of the same family and having similar growing traits.
Have you ever considered growing your own celery? There’s no comparison to the taste of fresh celery, and its really not as hard to grow as you might think.
Celery is a tiny seed that takes up to 3 weeks to germinate, which makes it a good candidate for starting indoors. We’ll start our celery around 12 weeks before the last frost, under grow lights at a consistent temperature around 70 degrees. Moisture should be even but not overdone.
When transplanting, makes sure temps are consistently above 55 degrees. Celery can withstand light frost, but too many cool nights and temps below 55 will cause early bolting.
Celery takes a long time to mature, so starting with strong plant development is essential. It does well in the high heat of summer here in Iowa, as long as we keep the soil moist, and we will usually start to harvest in August. That’s a long journey from seed to table!