Spring weather is unpredictable, and it can be hard to figure out when to transplant seedlings into the garden. After a long, cold winter, we are always anxious to dig in the dirt. But transplanting seedlings too early can just result in frustration if a late frost kills all of your hard work, and you have to replant everything. Ugh!
Knowing when it’s safe to transplant seedlings into the garden is extremely important. I mean, you spent all that time growing and caring for your seedlings, you don’t want them to die as soon as you plant them into your garden! Right?
The good news is that there are several types of vegetable seedlings that can be planted in early spring as soon as the soil is workable.
The soil is workable when it has thawed, and has dried out enough for planting. It’s easy to test your soil to see if it’s ready to be worked. Simply grab a handful of dirt and try to make a ball with it in your fist.
If the soil crumbles rather than forming a ball, then it’s ready to be worked. If the soil sticks together into a ball, that means it needs to dry out longer. Give it a few days and try testing it again. Sandy soils will dry out much faster then clay.
Harden Off Seedlings Before Transplanting
But hang on one second… before we talk about when to transplant seedlings into the garden, I want to make sure that you have taken the time to harden off your seedlings first.
This is a crucial step to ensuring that your seedlings will survive the transition to the garden. So you should never, never skip this step!
If you don’t harden your seedlings before transplanting them into the garden, they will probably die. If you haven’t taken this first step, then read this post first… How To Harden Off Seedlings
When to Transplant Seedlings
Once you have determined that your soil is workable, then it’s safe to start transplanting seedlings of cold hardy crops. Cold hardy crops are those that can survive cold temperatures and frost. Many of these crops actually grow best in cooler weather, and will be ready to harvest long before the heat of summer kicks in.
Examples of cold hardy crops that can be planted in early spring are: broccoli, cauliflower, kohlrabi and all plants in the cabbage family. Leafy greens, including lettuce, chard, kale and spinach. Onions, chives, leeks and others in the onion family. Root crops, like radish, turnip and carrots. Peas, cilantro, dill, parsley and celery are also on the list.
Other crops require warm soil and frost free weather before it’s safe to transplant the seedlings into the garden. Warm season crops shouldn’t be planted into the garden until all danger of frost has passed.
Many garden centers start selling vegetable plants several weeks earlier than they can safely be planting into the garden, so don’t let the fact that you can buy tomato plants in early spring fool you.
The seedlings of warm season crops will die if the temperature goes below freezing, or if they are exposed to frost. Wait until after the last frost date to transplant warm season seedlings like beans, tomatoes, squash, cucumbers, corn, eggplant, peppers, melons, okra, basil, potatoes and tomatillo.
Knowing Your Average Last Frost Date
How do you know when it’s safe to transplant seedlings of warm season crops? Well, first you need to know what your average last frost date is. Our average last frost date in the Minneapolis metro area is May 15th. But that is just an average.
There have been years where our last frost came in early May, and other years where it was weeks later. A few years ago we had our last frost on May 24th! If you don’t know the average last frost date in your area, check with a local garden center.
If you’re still feeling unsure about when to transplant seedlings into your garden, then wait until two weeks before your average last frost date to plant your cold season vegetable seedlings, and two weeks after your average last frost date to plant the warm season vegetable seedlings. It’s better to wait a week or two than to plant warm season crops too early.
Determining when to transplant seedlings into your garden can be tricky. Every year the last frost date will be different. The key is knowing your average last frost date, and then keeping your eye on the weather report.
If you’re new to gardening and want to learn exactly how to start garden seeds, check out my online Seed Starting Course! It’s a wonderful and fully comprehensive online course that you can take any time, from anywhere, and at your own pace.
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Do you know when to transplant seedlings into your garden? Share your tips in the comments below.