Swiss chard is relatively easy to grow, hardy, and packed with nutrition, and this green, leafy vegetable grows from a cluster of seeds. Many gardeners find it easier to start those seeds indoors then move the resulting seedlings outside once they’ve gotten a good start.
You should transplant your Swiss chard seedlings about four weeks after planting the seeds. Cotyledons appear first, and then the actual Swiss chard leaves appear. The second set of chard leaves appear before this four-week window closes, so don’t transplant until they’ve grown.
Swiss chard is a relatively fuss-free plant to grow, but even the toughest garden plants will suffer if you don’t maintain them correctly. So let’s look closer at our timetables for transplanting.

When Seedlings Are Ready
While you have the option of planting seeds directly in your garden, starting seeds indoors and then transplanting seedlings has its advantages:
- Starting indoors means you control how many plants you have. Sowing seeds in the ground is inexact, as you don’t know how many will come up or what critters might swipe a few seeds before they germinate.
- The controlled climate of an indoor setting allows more certainty. Keeping weather and water conditions constant puts less stress on the new plants.
- Planting seeds indoors means you can start your plants earlier. A late, hard freeze won’t cause your plants any issues when they’re indoors.
When you start indoors, there comes the point when your plants are ready to move outside. How do you know when that is, though?
The simple answer is that your seedlings should be ready to move outside about four weeks after planting them. However, you shouldn’t pick up your trays of plants and get them all in the ground on day one of that fifth week.
Thinning Your Seedlings
Chard seeds are clusters of seeds, so when you plant them, you will probably have multiple seedlings sprout in one spot. As we mentioned, starting seeds indoors gives you more control over how many plants you have.
The opportunity for that here lies in thinning your seedlings. Clip the seedlings you want to remove at the soil line. Don’t just rip them up out of the dirt, as you can harm the roots of the remaining plants that way.
Hardening Your Chard
If you’ve ever kept an aquarium, you may be familiar with the idea of acclimating a new fish to your tank. Remember when you were a kid and brought a new fish home from the pet store? You probably set the bag of fish and water in the tank and let the temperatures equalize so as not to stun the fish.
Hardening your seedlings works along the same lines.
Before you move your seedlings into their outdoor garden bed homes, they need time to acclimate to the weather and (generally) warmer outdoor temperatures. Also, as seedlings indoors, they’ve been getting regular watering, and they may not get that quite as well outdoors.
By moving your plants outside for a few hours a day, you can allow them to start adapting to what will be their new surroundings.
If you’ve started your seeds indoors when it’s still cold, pay attention to outdoor temperatures as you move them out.
- Start the plants off in a shady spot, as direct sunlight after a life indoors may be too much at first.
- Leave them outside for a maximum of three hours.
- Over the next 10 to 15 days, increase the plants’ time outside, ensuring they’re not out in inclement weather before they’re ready.
- Cut back on the plants’ daily watering, but don’t let them wilt.
After two weeks, your plants will have sufficiently adapted to the outdoors, and these hardened plants can go into the ground.
When To Plant Seeds
Since Swiss chard, like kale, likes cooler weather, many gardeners have the chance to plant early or late (or both). When you’ve started your seedlings indoors, when to plant, and when to transplant them to your outdoor space depends mainly on when you want to harvest your Swiss chard.

If you want smaller leaves (best used in salads and enjoyed uncooked), you can expect harvestable leaves about 30 days after you plant your seeds.
If you prefer larger leaves, say, for cooking with, you’ll need to wait a couple more weeks. Those larger leaves will need about 45 to 60 days from planting the seeds until harvest time.
Chard in the Spring
Like kale, Swiss chard is a biennial, meaning it has a two-year life cycle. If you transplant your chard seedlings in the early fall, you should be able to get leaves onto your dinner plate before winter.
Since chard likes the cooler weather, you should be able to harvest until temperatures drop below 30˚F (about 0˚C).
Then your biennial plant will close itself down for the season and overwinter. When spring arrives, your Swiss chard will begin its second season.
Chard in the Summer and Fall
Transplanting in the early spring allows for harvesting before the heat of summer kicks in, and things get too uncomfortable for this cool-weather plant. Since chard is relatively cold-hardy, you don’t have to wait for that last freeze before transplanting. A very hard freeze will cause problems, but you know your area’s climate and can work out when that hard freeze will come.
If you live in a cool spot, you might even be able to harvest your chard throughout the entire summer. High enough temperatures will cause bolting, which is the process of flowering that can make your chard taste bitter.
To stop bolting Swiss chard, remove the flowering stalk. You need to do this as soon as you notice bolting happening, and once you remove the bloom stalk, your plant should redirect its energies back into producing leaves instead of flowers and seeds.
The Act of Transplanting
You’ve planted seeds, watered them, raised some seedlings, and hardened them. Now it’s time to transplant those seedlings so you can have Swiss chard in your garden and then on your dinner table.
- Prepare the ground. The soil should be loamy, so if you live in an area with clay-rich dirt, be sure you’ve worked some compost into it beforehand.
- If at all possible, have planting day coincide with an overcast day. Hot, direct sun will be stressful even to hardened seedlings. Transplanting is traumatic.
- Get the spacing right. Planting chard close together will yield smaller leaves, which is fine for salads. Giving each Swiss chard plant more room means larger leaves, which you’ll want for cooking, as the process cooks the leaves down relatively small.
- Plant in rows. The rows should be about two feet apart, and within the rows, the plants should be between four and eight inches apart, depending on how much room you have and how big you want the leaves to grow.
Maintaining Your Transplanted Chard
Hopefully, your plot of Swiss chard gets lots of sun, as the plant only tolerates shade and will perform much better in full sun.
Past that, you can ensure good, healthy growth by watering and feeding your plants. Swiss chard needs between an inch and an inch and a half of water per week. Using a rain gauge can help you keep track of the water Mother Nature doles out, then you can water when needed.

Then there’s fertilizer. Different companies make specific fertilizer blends, and while there’s nothing wrong with those, chard likes blood meal and cottonseed meal. It’s organic, so it’s an eco-friendly way to deliver your plants the nitrogen they crave (and need for that rich green color you want).
Conclusion
While you don’t have to start your Swiss chard plant seeds indoors, doing so can benefit your plants and your gardening tasks. Once they’ve sprouted into seedlings, wait about four weeks to transplant them.
Once you’ve thinned and hardened your seedlings, plant them in good sun, and ensure they get regular water and fertilizer. As a cold-weather plant, Swiss chard, when taken care of, will put greens on your menu far into the fall, allowing for fresh vegetables longer than you’d expect.