17 Seeds With Long Germination Times to Start in December

While all seeds need moisture and the proper temperature to germinate, the time to sprout varies between different types. Some pop up in as little as a few days, while others take more than a month to germinate.

Knowing expected germination times can help you determine when to plant each seed. For example, you can sow quick germinating species a few weeks before you hope to transplant the seedlings outdoors. However, you’ll need to plan ahead if you want to grow plants that are slow to germinate.

The following plants take at least a few weeks to germinate under ideal conditions. When you factor in less-than-ideal temperatures and variations in seed genetics, some of them can take more than a month to sprout! Therefore, starting these seeds in December gives them plenty of time to germinate and grow before transplanting season arrives.

Factors Affecting Germination Times

All of the plants on this list are slow to germinate. However, germination times can vary within a single crop variety! That’s because factors like temperature and moisture levels largely impact germination times.

If you want your seeds to sprout ASAP, provide them with moist soil and the ideal soil temperature. Some seeds germinate best when the soil temperature is at 90°F (32°C), while others are happiest when the soil is near 70°F (21°C). Others need a period of near freezing temperatures to sprout. You can often find the ideal germination temperature and treatments on the seed packet, but you can also research this factor online.

You should also pay attention to light and seed depth. Some require light to germinate, and others need darkness. Therefore, burying a seed too deep or too shallow can lead to germination problems.

Seed quality can also impact germination times. Old and improperly stored seeds may have difficulty sprouting. So, check the seed packet date if your seeds aren’t germinating.

Do I Really Need to Start Seeds as Early as December?

It depends! The ideal time to start seeds varies based on your growing zone, intended planting date, and protective coverings.

For example, if you live in USDA hardiness zone 9, you’ll probably sow earlier than your friend in zone 6. However, if your friend has access to a high tunnel or doesn’t mind covering their plants with layers of row cover, they may be able to start at a similar time.

In general, starting seeds earlier will lead to an earlier harvest date, but the plants will require more protection from the cold. If you want to limit the risk of cold damage, you can start in January or February.

Seeds to Start in December

All of the following plants have with germination periods greater than a week. Some of the seeds will sprout in ten days under ideal conditions, and others can take more than a month to germinate in an average household environment.

Most of these plants are also relatively cold-hardy, so they can survive below-freezing temperatures if you protect them with a layer of row cover. Therefore, it’s possible to transplant them outdoors before the last spring frost occurs. 

Asparagus

Known for its tender green stalks that burst through the soil in the spring, asparagus is on the wish list of many veggie gardeners. Since the plants are perennials, you can plant them once and enjoy a yearly harvest for years. Just be aware it can take a few years for an asparagus patch to become established enough to harvest.

When it’s time to plant, you can choose from either asparagus seeds or crowns. Crowns establish more quickly but also cost more. Therefore, seeds are a good option if you want to save some money.

Asparagus takes around three weeks to germinate at the ideal temperatures. Aim to keep the soil between 65-75°F (18-24°C) to encourage germination. After they sprout, place the plants under grow lights and plant them outdoors when the danger of frost has passed.

Lavender

Lavender’s lovely purple flowers and delightful fragrance make it a great addition to herb and flower beds. No matter which type of lavender you want to grow, starting from seed is one option. While this is slower than growing from cuttings, it’s less expensive and allows you to grow rare varieties you can’t find in greenhouses or plant nurseries.

Lavender varieties vary in germination time, but most take between two and 12 weeks to sprout. However, it’s not unheard of for some to take a few months to germinate. Therefore, it’s best to start these seeds in wintery December or January.

They germinate best with cold stratification, so place them on a slightly moist paper towel, then pop them in the refrigerator for a month. When it’s time to plant, remove the seeds and sprinkle them on top of trays filled with a well-draining mix. Keep the soil moist and place the trays in a bright area between 60-70°F (16-21°C).

Parsley

Whether you like Italian flat-leaved parsley or a curly variety, there’s no replacing the flavor of parsley. Since this herb grows after you harvest, you can enjoy a single parsley plant all year.

Planting parsley from seed is easy as long as you are patient. The tiny seeds take multiple weeks to germinate, and the seedlings often grow slowly. Therefore, it’s best to sow them a few months before you hope to transplant them outdoors.

Keep the soil moist and between 50-85ºF (10-29°C). While they may germinate in as little as two weeks, some parsley seeds can take longer than a month to sprout. Therefore, don’t toss them after a few weeks.

Celery

If you live in a warm area or don’t have access to an ideal seed-starting setup, you can start celery in December. Celery seeds take multiple weeks to germinate, but they like to be transplanted once the weather remains above freezing. Therefore, pay attention to your last predicted frost date before sowing—aim to sow 10-12 weeks before your last frost.

Since celery requires light to germinate, avoid burying them. Instead, gently press them into the top of the soil. Keep the area between 70-80°F (21-27°C) for the best germination.

The seedlings should emerge in two to three weeks. Once you see the first set of true leaves, you can reduce the temperatures to 60-70°F (16-21°C). Keep the seedlings well-watered and plan to transplant them outdoors a couple of months later.

Verbena

Known as purple top verbena or tall verbena, this tender perennial has clusters of small purple flowers atop long, slender stems. The flowers attract pollinators of all kinds and also work well in bouquets.

Verbena takes two to four weeks to germinate, so planting them early is a good idea. They germinate best when warm days (75-85°F or 24-29°C) with cool nights (55-65°F or 13-18°C). This change in temperature helps the seeds break dormancy and germinate. One way to encourage this change in temperature is to put your trays on heat mats that you turn off at night.

Aim to keep the potting soil only slightly moist. Verbena is sensitive to wet soil and may rot if the growing medium stays moist. You should also barely cover the seeds for the best results.

Artichoke

If you live in growing zones 6-10, you can try growing artichokes at home. Healthy plants will produce buds that are large enough to harvest, and even subpar crops will add a unique look to your garden.

You can propagate new plants by division or cuttings if you already have access to artichoke plants. Starting from seed is a great option if you can’t find plants or want to grow a unique variety. Just make sure to start the seeds early—around December or January—since they’re slow to germinate and take a long time to mature.

Plant in a well-draining seedling mix about a quarter of an inch below the soil. Keep the soil moist and between 70-80°F (21-27°C). Under these conditions, the seedlings should pop within one to three weeks. You can plant mature seedlings outdoors a few weeks before your last spring frost date.

Rosemary

Rosemary plants’ deep green leaves and delicate purple flowers work well in ornamental landscapes and edible gardens. While many gardeners choose to buy rosemary seedlings from a nursery or root cuttings to form new plants, you can also start this herb from seed.

This herb takes two to four weeks to germinate under ideal conditions. Sprinkle the seeds on the soil surface and avoid covering them to ensure they receive light. Make sure to use a well-draining and moderately moist soil mix and keep it between 65-75°F (18-24°C).

Once the seedlings emerge, ensure they receive at least ten hours of bright light. You can transplant the plants to individual containers once they have four sets of leaves and plant them outdoors after the last frost.

Radicchio

A member of the chicory family, radicchio is a slightly bitter green known for beautiful shades of green, red, and pink. Although the plants sometimes get a bad rap for being disgustingly bitter, well-grown radicchio is a garden delicacy. One trick to growing great radicchio is allowing the plants to grow in cool temperatures. That means starting seeds early in the season (around December in warmer climates) if you want to enjoy a spring crop.

Although radicchio doesn’t take long to germinate, an early sowing time allows you to get the seedlings into the ground early. Since these plants are cold-hardy, they don’t mind below-freezing temperatures as long as they’re protected with row cover. You can expect the seedlings to be ready to transplant about a month after sowing.

Keep in mind that all types of radicchio prefer cool temperatures to germinate. If the soil temperature rises above 77°F (25°C), the seeds can enter thermal dormancy and fail to germinate. The ideal germination temperature is between 60-68°F (16-20°C).

Sea Holly

Also known by its genus name Eryngium, this flowering perennial adds a unique element to bouquets. The flowers resemble small thistles with spiny bracts surrounding the flower heads. You can find blue and green versions of this unique plant.

Although sea holly only takes a week or two to germinate, the seedlings are slow growers. Starting them early in the season allows you to grow mature transplants by the time the last spring frost arrives.

These seeds require light to germinate, so avoid covering them with soil. Bottom water or gently top water to avoid covering them. Keep the soil slightly moist and between 70-75°F (21-24°C).

Foxglove

Foxglove is a must-have in cottage gardens, cutting beds, and everything in between. The plants produce numerous spikes covered with large, bell-shaped flowers. You can find both perennial foxgloves that bloom in their first year and biennial varieties that flower in the second year.

Growing from seed allows you to take advantage of the many foxglove varieties and colors. These seeds take a couple of weeks to germinate and are slow growers, so an early start date in December allows for timely spring plantings.

Foxgloves require light to sprout, so avoid covering them with soil and bottom water. Keep the temperature between 65-70°F (18-21°C), and they should germinate within three weeks. You can transplant the seedlings outdoors a few weeks before the last frost as long as you use row cover to protect the plants from cold.

Delphinium

If I had to pick a favorite spring flower, it might be delphinium. There’s something irreplaceably impressive about seeing the plants go from tiny seedlings to towering stems covered with delicate flowers. One way to end up with tall stems is to transplant seedlings when it’s still cold and then protect them throughout the winter.

Starting seeds indoors in December allows you to end up with healthy transplants in February or March. Delphinium seeds germinate best between 65-70°F (18-21°C) and should sprout in two to three weeks. When the seedlings emerge, move them to a cooler location that’s between 50-60°F (10-16°C).

You can transplant the seedlings into the ground after the last frost. Or, you can plant a few weeks before your last frost date as long as you protect the plants with row cover.

Larkspur

I like to think of larkspur as delphinium’s younger cousin. Both of the plants produce tall flower spikes covered with open blooms, but larkspur is a bit smaller and more delicate than delphinium. The seeds also have different germination requirements.

Larkspur requires cool, dark conditions to germinate. Cover the seeds with about a quarter of an inch of soil and place them somewhere below 55°F (13°C). You can also pop the seeds in your fridge for a week before sowing to speed up the germination process. Under the right conditions, the seedlings should sprout in two to three weeks.

Continue to grow the larkspur seedlings in a cool area. When the seedlings have a few sets of true leaves, you can transplant them outdoors. Just make sure to cover the plants with row cover if temperatures are expected to drop below freezing.

Snapdragon

Snapdragon’s ability to tolerate cool weather means they’re ideal spring flowers. In warm climates, you can transplant seedlings in the fall and overwinter them in a high tunnel or under row cover. This planting schedule will lead to tall stems and healthy blooms.

However, if you live in a colder climate or missed the fall planting window, spring planting will work just fine. Snapdragons take between one and three weeks to germinate when they are kept between 70-75°F (21-24°C). They need light to germinate, so place them on the soil surface or lightly cover them with vermiculite.

After the seedlings develop three sets of true leaves, pinch off the top set of leaves. This will encourage the plants to develop a bushier form and produce more stems. You can transplant the seedlings outdoors a few weeks before the last frost.

Lupine

At home in gardens, fields, and bouquets, lupine’s large flower spikes make it a favorite of many growers. The blooms come in shades including pink, purple, and white, and the perennial plants produce flowers year after year.

Lupines can be difficult to germinate due to their hard seed coat. Soaking the seeds overnight or scarifying them will encourage germination. As long as you complete either of these practices, and keep them between 65-75°F (18-24°C), you should see plants emerge in two to three weeks.

These plants develop a sensitive taproot system, so it’s best to plant them in large containers and transplant them before they’re rootbound. The seedlings can tolerate a light frost, so you can plant them a few weeks before your last frost date.

Lisianthus

Known for their gorgeous flowers that seem to last forever in a vase, lisianthus plants also have a reputation for being extremely slow growers. The plants seem to remain the same size for weeks, especially in the short days of winter. Therefore, starting the seeds in December or January is key if you want to enjoy blooms in the summer.

Place the seeds on top of the soil, then cover them with a thin layer of vermiculite. This will let light in but help keep them moist and limit algae growth. Keep temperatures between 65-75°F (18-24°C), and they should germinate within 10-15 days.

After the seedlings emerge, keep them somewhere between 60-70°F (16-21°C), provide good ventilation, and keep the soil consistently moist. The plants often take two and a half months to reach a size that’s ready for transplanting, so be patient! Make sure to plant before the seedlings are rootbound since this can lead to undesirable short stems.

Columbine

A beloved native plant with numerous species and varieties, columbine is at home in pollinator habitats, shade gardens, and cutting beds. If you want to grow the plants from seed, take note that they take three to five weeks to germinate. That means sowing in December will help you end up with sizable transplants for spring.

Stick the seeds in the refrigerator for 3 weeks prior to planting. Sprinkle them on the surface, then only lightly cover them to make sure they receive light. If you sowed multiple seeds per container, pot up the seedlings when they have two to three sets of true leaves.

You can transplant columbine outdoors a few weeks before your last frost. Just make sure to harden them off before planting! The seedlings won’t mind a light dusting of frost, but you should cover them in the event of a heavy freeze.

Echinacea

Also known as coneflower, the Echinacea genus contains handfuls of different species. All of these perennials work well for cutting, provide food for pollinators, and produce seeds that songbirds love. Plus, they look gorgeous in the garden.