Written by - Kaitlynn from MIgardener
This new blog series is written primarily for our northern dwelling readers. In the next few weeks, we will be laying out a few of the foundational varieties we recommend to start indoors in our region during mid-March, early-April, late-April, etc. Later, we'll talk more about what we will be directly sowing as the weather warms up outside.
A helpful reminder for Northern gardeners, and any gardeners really; there is no need to start seeds indoors if you do not have the proper space or light. Sometimes direct sowing seeds outdoors is a much more efficient way of starting things. Plus, not all varieties require 80-degree soil for successful germination! There are a handful of seeds that northerners can direct sow while there is still visible snow on the ground and danger of frost. To learn more about what you can start outdoors in early spring, check out our most recent video! However, if you have space and the supplies to begin indoors, this post will help you learn more about what you can get a headstart on for an earlier harvest in the garden.
Here are the varieties northerners should start indoors in late April:
Germination time: 2-15 days
Germination Temp: 35-80 degrees F
You will notice that the seed varieties in this post all have much quicker germination rates compared to the last few posts. In late April, the chances are that you will have a handful of weeks left until the last frost passes. Seed starting in this perfect window of time will get these faster-growing varieties prepared for transplanting. Lettuce matures quickly and tolerates cold weather. Starting lettuce too soon would result in transplant shock and stunt the growth of the plant. Starting lettuce indoors is especially helpful if you are planting heading varieties. Leaf lettuce is extremely simple to grow in a cut-and-come-again garden, but if you are growing romaine or iceberg style lettuce, letting the plants grow stronger indoors is beneficial. For a full lettuce growing guide, check out this video or this blog post.
Germination Time: 4-20 days
Germination Temp: 45-85 degrees F
Cabbage grows well under the colder conditions of Northern regions. It can withstand temperatures down to 20 degrees F. Your primary goal with cabbage is to avoid starting them too early; this can result in them growing too big indoors to thrive after transplanting. Cabbage seed requires slightly warmer temperatures to get started, which is why you can save time in the garden by starting them indoors. If you start them at this time, you'll be able to harvest the first crop in mid-July, leaving plenty of time to start a second round for a fall harvest! Check out this complete cabbage growing guide video for more info on this subject.
Germination Time: 6-10 days
Germination Temp: 40-100 degrees F
Kale will thrive all season long, producing rich flavor in the cold seasons, and incredible leaf growth in the heat. If northerners start kale any earlier than late spring, it could be damaging to the plant. Early starts could result in root-bound starters, which would make the plants perceptible to root-knot nematode, a parasite that could cause the plant to die. Giving them a few weeks to get started will give them time to grow strong enough to transplant perfectly. For a full kale growing guide, click here, and for a video tutorial, click here.
Germination time: from 4-20 days
Germination Temp: approx. 45-85 degrees F
Important note: our suggestion to Northern gardeners would be to only start sprouting varieties of broccoli (ex. broccoli rabe, purple sprouting broccoli) indoors for the best results. Classic heading varieties will not do well if started indoors. Planting sprouting broccoli will allow you enough time for two harvests in a year if you start the seeds indoors at the right time. Broccoli grows well under cool temperatures, and sprouting varieties will only get sweeter. The heat will cause broccoli to bolt early, so starting from seed in early spring is the best way to get it started. For more on growing broccoli, click here.
Germination Time: 3-10 days
Germination Temp: 65-100 degrees F
If you have space, late April is the perfect time to start large vining crops indoors. Especially in northern climates, starting things like watermelons will extend their growing season and allow them to enjoy more of the hot season fully established. This will enable them to produce massively sized produce instead of struggling at the end of the season. It's also helpful to start them early to make sure their starters will be healthy and strong enough before they are planted out. For our more on growing vining crops, click here. For a video tutorial, click here.
Keep your eyes open for future posts! Hopefully, these posts will help all of our midwestern and Michigan friends plan their best gardens ever in 2020.
Main Sources: linked throughout