Heirloom seeds: The ultimate guide to selecting and growing heirloom seeds

Heirloom seeds are popular with home gardeners, but what exactly is an heirloom seed? The true definition is often debated, but most experts classify an heirloom variety as one that is open-pollinated and has been in cultivation for at least fifty years. In my own vegetable garden, many of our favorite crops are heirloom varieties like Cherokee Purple tomato, Fish pepper, Lemon cucumber, and Dragon’s Tongue bean. Read on to learn more about heirloom seeds and why they make such great garden plants.

Types of garden seeds 

There are two main types of seeds grown in home gardens: heirloom seeds and hybrid seeds. They each have their advantages and disadvantages. Hybrids, for example may be more disease resistant than heirlooms, but heirloom varieties often have better flavors.

Heirloom seeds 

The term ‘heirloom’ or ‘heritage’ is often used to describe seed varieties, but what does it really mean? As noted above, most experts define heirloom seeds as those that are open-pollinated and have been in cultivation for at least fifty years, although some prefer to classify heirlooms as those grown before World War II. Open-pollinated plants produce seeds that breed ‘true to type’. That means when you save and then plant the seeds of an open-pollinated variety, you’ll end up with a plant that is very similar to the original parent plant. If you plant seeds from a Brandywine tomato you grew in your garden, you’ll end up with another Brandywine tomato plant. 

For open-pollinated, heirloom vegetables that are self-pollinating like beans, peas, tomatoes, and lettuce, it’s easy to collect the seeds once they’ve dried or ripened. However, some types of open-pollinated crops, like cucumbers and squash, can cross pollinate if more than one variety is grown. If you want to save seeds from these vegetables, you’ll need to make sure cross pollination doesn’t occur. To do that, you can 1) grow one variety each season 2) isolate different varieties by spacing them very far apart or 3) use insect barrier fabrics to prevent bees from moving pollen between varieties. 

Hybrid seeds

Hybrid seeds are the product of two different but compatible plants that are crossed by breeders to create a new variety. The new variety, often labelled an F1 has characteristics from each parent with the goal of including improved traits like early maturity, disease resistance, improved vigor, or a larger yield. Popular hybrid vegetable varieties include Sungold tomatoes, Everleaf basil, and Just Sweet pepper. 

Gardeners often ask me if hybrid seeds are similar to GMO seeds and while they are a product of breeding, they have not been genetically modified. It can take years and thousands of failed attempts to produce a new hybrid variety which is why the seeds are typically more expensive than heirloom seeds. Unlike heirlooms which are open-pollinated, saving seed from hybrids doesn’t reliably produce true-to-type plants. That means you need to buy new seeds for hybrid varieties every year.

6 reasons to plant heirloom seeds

When reading heirloom seed catalogs, you’ll often see stories about individual varieties, their approximate age, and how they came to be discovered. These are fun to read and add to the mystique of heirloom seeds, but there are many advantages to planting heirloom vegetables, herbs, and flowers in your garden. Here are six reasons to grow heirloom varieties:

1. Flavor – Pop a sun-warmed heirloom Black Cherry tomato into your mouth and you’ll quickly learn how flavor has become a huge selling point for heirloom seeds. In fact, it’s THE reason many gardeners plant heirlooms. They’re after the flavors they remember enjoying from their grandparents vegetable gardens. Often newer hybrids are bred for characteristics like early maturity, disease resistance, and longevity, but they sacrifice flavor. When you’re growing your own vegetables, you want to grow those that taste knock-your-socks-off DELICIOUS! Most heirloom varieties have been preserved through generations because of their improved flavors, but it’s not just heritage tomatoes that taste exceptionally good. Expect most types of heirloom crops – from cabbages to pole beans, lettuce to melons to be fully flavored.
2. Diversity – Flip through the tomato section of any heirloom seed catalog and it’s likely you’ll find at least a few dozen varieties to grow. And while red tomatoes have been the standard in supermarkets, thanks to savvy seed savers we now have access to heritage varieties in hues of yellow, orange, white, burgundy, purple, and pink. It’s not just heirloom tomatoes that enjoy incredible diversity, there are many vegetables with varieties having unusual hues and/or shapes; Cosmic Purple carrot, Dragon’s Egg cucumber, Musquee de Provence winter squash, and Blue Podded pea, for example.
3. Preservation – Growing heirloom varieties helps preserve them for future generations. Genetic diversity is key to survival and having a large number of varieties in cultivation offers insurance if disease or other issues affect a certain variety.
4. Seed saving – It’s easy to collect and save the seed from most heirloom vegetables and flowers. Once seeds are thoroughly dry, they can be placed in labelled seed envelopes and stored in a dry location. The seeds can then be planted the next season with extras being shared with friends and family.
5. Less expensive – Heirloom seeds are often less expensive to buy than hybrid varieties, which are the result of carefully controlled plant breeding. 
6. Locally adapted varieties – For vegetable gardeners, a big advantage of growing open pollinated varieties is that by gathering the seed from their best plants each year, they can create strains that are specifically adapted to their growing region. For example, if I grow an heirloom tomato like Cherokee Purple in my vegetable garden each year, consistently saving the seeds from the plant with the best qualities (early maturity, large crop, vigorous plants, disease resistance), I would eventually have a strain that was better adapted to my region and climate. 

Ten heirloom seeds to grow in your vegetable garden

There are thousands of heirloom varieties available through seed companies and as you select seeds to grow don’t forget to pay attention to information like days to maturity, plant size, and disease resistance. Days to maturity is very important as northern gardeners may not have time to ripen long season crops like late maturing heirloom tomatoes, tomatillos, or melons. When I first read about the heirloom watermelon, Moon and Stars I was so excited to grow it. Unfortunately, I didn’t pay attention to the days to maturity information listed in the seed catalog and it proved to need a longer, warmer season than my garden could provide. Now, I grow earlier maturing watermelon like Sugar Baby. Learn more about many of my favorite heirloom varieties in my award-winning book, Veggie Garden Remix.

1) Cherokee Purple tomato – This wonderful heirloom variety was introduced to gardeners by Craig LeHoullier, the author of Epic Tomatoes. The large fruits have deep burgundy-purple skin and a complex, sweet flavor that can’t be matched by any supermarket tomato! The seeds landed in LeHoullier’s hands thirty years ago when a letter arrived in his mail from John Green of Tennessee. The tomato seeds had been passed along to Green and were said to originate from the Cherokee nation. LeHoullier planted the seeds and when he realized what a gem the variety was, he shared them with friends at various seed companies. Soon, Cherokee Purple was introduced to the wider world and became of favorite of food gardeners everywhere.

2) Brandywine tomato – Perhaps the most popular heirloom tomato grown in gardens, Brandywine yields hefty fruits that can weigh more than one and a half pounds. The tomatoes are a deep reddish pink in color and make the BEST tomato sandwiches. Brandywine plants take around 85 days to go from transplant to harvest and in my northern garden we start to pick the fruits in early September. If you live in a short season region, plant faster maturing heirloom tomatoes like Costoluto Genovese, Moskvich, and Carbon.

3) Lemon cucumber – Twenty-five years ago, I read the description for Lemon cucumber in a seed catalog and was so intrigued I ordered a packet. This was my introduction into growing heirloom seeds and we loved this unique variety so much that we still grow it every year. Lemon cucumber fruits are rounded and best harvested when they’re two to three inches across and pale green in color. They mature to a bright yellow (like a lemon) but at that point, they’re quite seedy so harvest when immature.

4) Chioggia Guardsmark beet – This beautiful beet is traced back to Chioggia, Italy and is often called the ‘candy striped’ beet for its unique interior rings of pink and white. Beets are quick to grow and Chioggia is ready to pull about two months from seeding. Enjoy the sweet, earthy roots as well as the deep green tops.

5) Musquee de Provence pumpkin – Winter squash are the glory of the autumn garden and when it comes to heirloom varieties, there is no shortage of varieties to grow. I plant heritage varieties like Black Futsu, Candy Roaster and Galeux D’Eysines, but my absolute favorite is Musquee de Provence. The plants yield several fruits per vine with each weighing up to twenty pounds. They are large, flattened pumpkins with deep lobes and dark green skin that matures to a lovely orange-mahogany. The bright orange flesh is rich and sweet and wonderful when roasted in the oven.

6) Rouge D’ Hiver lettuce – ‘Red of Winter’ lettuce is a cold tolerant salad green with deep burgundy-green leaves that are tender and crisp. We sow seeds in late winter in cold frames and our polytunnel for an extra-early harvest, and in the open garden once the soil temperature is around 40 F. It’s also ideal for fall and winter crops if grown under protection. Harvest the leaves as a baby crop or cut whole heads as they mature. Just be sure to leave a plant in the garden to flower and form seeds so you can collect them and grow it again and again and again.

7) May Queen lettuce – There are a lot of butterhead lettuce varieties available from seed companies but May Queen is an exceptional heirloom. The small to medium-sized heads have crinkly golden-green leaves that blush to rose at the heart. The leaves are super tender and I plant several dozen seedlings in spring and again in autumn so we have plenty of May Queen to harvest.

8) Dragon’s Tongue bean – I don’t grow a lot of bush beans, preferring pole varieties, but I do grow Dragon’s Tongue every summer. The plants are very productive, yielding a heavy crop of tender pods that can be eaten as snap beans, allowed to mature for fresh shell beans, or left to dry in the garden for dried beans. The butter yellow pods are streaked with bright purple and the interior beans are creamy white and splashed with violet purple. Gorgeous!

9) Costata Romanesco summer squash – A family vegetable garden can probably get by with just one zucchini plant, but there are so many wonderful varieties to grow, I always plant at least four types. I’ve been growing Costata Romanesco for the past decade and love the high productivity, unusual ribbed fruits, and edible blossoms. Each squash has medium green and light green stripes and is more richly flavored than other varieties of summer squash. As with most zucchini, the fruits can grow large – up to 18 inches long – but harvest them when immature. We often pick them with the blossoms still attached. They can be sautéed, pan fried, or grilled with a drizzle of olive oil and garlic for a tasty summer treat. If you want to save seeds from your heirloom squash, grow just one variety as they cross pollinate very easily.

10) Purple Podded pole bean – Purple pole beans are both ornamental and delicious and I grow the plants up tunnels so we can enjoy the purple-tinged foliage as well as the deep purple pods. This variety was discovered in an Ozark garden about 90 years ago and was soon shared with seed catalogs, becoming popular across North America. The vigorous vines grow seven to eight feet tall and yield dozens of six to eight inches long flattened purple pods. When cooked, the beans turn green. Enjoy them as a snap bean or let the pods dry on the vine for dried beans.

Heirloom seed companies

There are many companies that specialize in heirloom seeds or sell them along with hybrid varieties. Below you’ll find some of my favorite seed catalogs that offer heirloom varieties. Please let us know about your go-to heirloom seed suppliers in the comments.

US:

• Baker Creek Heirloom Seeds
• High Mowing Organic Seeds
• Seed Savers Exchange
• Southern Exposure Seed Exchange
• Fedco Seeds
• Peaceful Valley Seeds
• Johnny’s Selected Seeds
• Territorial Seed Company
• Seeds of Change

Canada:

• Yonder Hill Farm
• Annapolis Seeds
• Heritage Harvest Seed
• Salt Spring Seeds
• Hope Seeds
• Urban Harvest
• Solana Seeds

For more information about heirloom seeds and seed saving, be sure to check out these articles: 

• Collecting seeds from your garden
• Fish pepper: a spicy and delicious heirloom variety
• Heirloom tomatoes to grow in your garden
• Cucuamelon: a popular heirloom vegetable
• 5 questions with heirloom tomato expert Craig LeHoullier